From 99baacb1f33acaea45b00e6661c29302b01562a6 Mon Sep 17 00:00:00 2001
From: ottjk <joshott16@gmail.com>
Date: Sun, 31 Dec 2023 15:01:25 -0500
Subject: sway and tex

---
 texmf/source/latex/revtex/revtex4-2.dtx | 8383 +++++++++++++++++++++++++++++++
 1 file changed, 8383 insertions(+)
 create mode 100644 texmf/source/latex/revtex/revtex4-2.dtx

(limited to 'texmf/source/latex/revtex/revtex4-2.dtx')

diff --git a/texmf/source/latex/revtex/revtex4-2.dtx b/texmf/source/latex/revtex/revtex4-2.dtx
new file mode 100644
index 0000000..f6e0b1c
--- /dev/null
+++ b/texmf/source/latex/revtex/revtex4-2.dtx
@@ -0,0 +1,8383 @@
+% \iffalse meta-comment balanced on line 122
+% revtex4-2.dtx: package to typeset APS, AIP, SOR, ASA, etc. journal articles
+% Copyright (c) 2019 American Physical Society.
+% https://journals.aps.org/revtex/
+% mailto:revtex@aps.org
+%
+% Disclaimer
+%   This file is distributed WITHOUT ANY WARRANTY;
+%   without even the implied warranty of
+%   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+% License
+%   You may distribute this file under the conditions of the 
+%   LaTeX Project Public License 1.3c or later 
+%   (http://www.latex-project.org/lppl.txt).
+% ReadMe
+%   For the documentation and more detailed instructions for
+%   installation, typeset this document with \LaTeX.
+% Maintenance Status
+%   This work has the LPPL maintenance status "maintained";
+%   Current Maintainer of this work is Arthur Ogawa.
+%
+% This work consists of the main source file revtex4-2.dtx
+% and the derived files
+%    revtex4-2.cls, revtex4-2.pdf
+% Distribution:
+%    CTAN:macros/latex/contrib/revtex/
+%
+% Unpacking:
+%    tex revtex4-2.dtx
+%
+% Documentation:
+%    latex revtex4-2.dtx; ...
+%
+%    Programm calls to get the documentation (example):
+%       pdflatex revtex4-2.dtx
+%       makeindex -s gind.ist revtex4-2.idx
+%       makeindex -s gglo.ist -o revtex4-2.gls revtex4-2.glo
+%       pdflatex revtex4-2.dtx
+%       makeindex -s gind.ist revtex4-2.idx
+%       pdflatex revtex4-2.dtx
+%
+% Installation:
+%    TDS:bibtex/bst/revtex/
+%    TDS:doc/latex/revtex/
+%    TDS:tex/latex/revtex/
+%    TDS:source/latex/revtex/
+%
+% Thanks, Heiko!
+%    This method of letting a single .dtx file serve as both
+%    documentation (via latex) and installer (via tex) follows
+%    the example of Heiko Oberdiek. Thanks!
+%<*ignore>
+\begingroup
+  \def\x{LaTeX2e}%
+\expandafter\endgroup
+\ifcase
+ 0\expandafter\ifx\csname processbatchFile\endcsname\relax\else1\fi\ifx\fmtname\x\else 1\fi
+ \relax
+\else
+ \csname fi\endcsname
+%</ignore>
+%<*install>
+%% This file will generate documentation and runtime files
+%% from revtex4-2.dtx when run through TeX.
+\input docstrip
+\preamble
+
+This file is part of the APS files in the REVTeX 4 distribution.
+For the version number, search on the string %FileInfo
+
+Original version by David Carlisle
+Modified by Arthur Ogawa (mailto:arthur_ogawa at sbcglobal dot net)
+
+Version (4.2a, unreleased)
+Modified by Aptara on behalf of American Physical Society and American Institute of Physics
+
+Version (4.2b,4.2c)
+Modified by Mark Doyle, American Physical Society (mailto:revtex at aps.org)
+
+Version (4.2d,4.2e)
+Modified by Phelype Oleinik for the American Physical Society (mailto:phelype.oleinik at latex-project.org)
+
+Copyright (c) 2019--2020 American Physical Society.
+https://journals.aps.org/revtex/
+mailto:revtex@aps.org
+
+See the REVTeX 4.2 README-REVTEX file for restrictions and more information.
+
+\endpreamble
+\askforoverwritefalse
+\keepsilent
+\generate{%
+  \file{revtex4-2.cls}{%
+   \from{revtex4-2.dtx}{kernel}%
+   \from{ltxutil.dtx}{kernel}%
+   \from{ltxfront.dtx}{kernel}%
+   \from{ltxgrid.dtx}{kernel}%
+   \from{revtex4-2.dtx}{options}%
+   \from{ltxutil.dtx}{options}%
+   \from{ltxfront.dtx}{options}%
+   \from{ltxgrid.dtx}{options}%
+   \from{revtex4-2.dtx}{package}%
+  }%
+  \file{aps4-2.rtx}{\from{revtex4-2.dtx}{aps}}%
+  \file{apsrmp4-2.rtx}{\from{revtex4-2.dtx}{rmp}}%
+  \file{aps10pt4-2.rtx}{\from{revtex4-2.dtx}{10pt}}%
+  \file{aps11pt4-2.rtx}{\from{revtex4-2.dtx}{11pt}}%
+  \file{aps12pt4-2.rtx}{\from{revtex4-2.dtx}{12pt}}%
+  \file{revsymb4-2.sty}{\from{revtex4-2.dtx}{revsymb}}%
+}%
+\ifToplevel{
+\Msg{***********************************************************}
+\Msg{*}
+\Msg{* To finish the installation, please move}
+\Msg{*    *.cls, *.rtx, and *.sty }
+\Msg{* into a directory searched by TeX;}
+\Msg{* in a TDS-compliant installation:}
+\Msg{* texmf/tex/macros/latex/revtex/.}
+\Msg{*}
+\Msg{* To produce the documentation,
+       run revtex4-2.dtx through LaTeX.}
+\Msg{*}
+\Msg{* Happy TeXing}
+\Msg{***********************************************************}
+}
+\endbatchfile
+%</install>
+%<*ignore>
+\fi
+%</ignore>
+% \fi
+%
+% \GetFileInfo{revtex4-2.dtx}
+%
+% \StopEventually{}
+% \iffalse ltxdoc klootch
+%<*package>
+%%%  @LaTeX-file{
+%%%     filename        = "revtex4-2.dtx",
+%%%     version         = "4.2e",
+%%%     date            = "2020/10/03",
+%%%     author          = "Mark Doyle (mailto: revtex at aps.org), Arthur Ogawa (mailto:arthur_ogawa at sbcglobal.net),
+%%%                        commissioned by the American Physical Society.
+%%%                        ",
+%%%     copyright       = "Copyright (C) 1999, 2009 Arthur Ogawa, Version 4.2 Copyright (C) 2019 American Physical Society
+%%%                        distributed under the terms of the 
+%%%                        LaTeX Project Public License 1.3c, see
+%%%                        ftp://ctan.tug.org/macros/latex/base/lppl.txt
+%%%                        ",
+%%%     address         = "Mark Doyle,
+%%%                        USA",
+%%%     telephone       = "",
+%%%     FAX             = "",
+%%%     email           = "mailto colon revtex at aps.org",
+%%%     codetable       = "ISO/ASCII",
+%%%     keywords        = "",
+%%%     supported       = "yes",
+%%%     abstract        = "",
+%%%  }
+%</package>
+% \fi
+%
+% \iffalse ltxdoc klootch
+% The following references the \file{README-REVTEX.tex} file,
+% which contains the frontmatter for the programmer's docs.
+% The contents of this file are generated when
+% you typeset this file with LaTeX.
+% Search on "{filecontents*}{README-REVTEX.tex}" to locate it.
+% \fi\input{README-REVTEX.tex}%
+%
+% \subsection{Bill of Materials}
+%
+% Following is a list of the files in this distribution arranged
+% according to provenance.
+%
+% \subsubsection{Primary Source}%
+% One single file generates all.
+%\begin{verbatim}
+%revtex4-2.dtx
+%\end{verbatim}
+%
+% \subsubsection{Generated by \texttt{tex revtex4-2.dtx}}%
+% Typesetting ths file under \TeX\ itself runs the installer, 
+% which generates the package files.
+%\begin{verbatim}
+%revtex4-2.cls, revtex4.ins, revtex4.drv, aps4-2.rtx, 
+%aps10pt4-2.rtx, aps11pt4-2.rtx, aps12pt4-2.rtx, revsymp.sty
+%\end{verbatim}
+%
+% \subsubsection{Generated by \texttt{pdflatex revtex4-2.dtx}}%
+% Typesetting the source file under \LaTeX\
+% generates the documentation.
+%\begin{verbatim}
+%revtex4.pdf, 
+%\end{verbatim}
+%
+% \subsubsection{Auxiliary}%
+% The following are auxiliary files generated
+% in the course of running \LaTeX:
+% \begin{verbatim}
+%revtex4.aux revtex4.idx revtex4.ind revtex4.log revtex4.toc
+% \end{verbatim}
+%
+% \section{Code common to all modules}%
+%
+% The following may look a bit klootchy, but we
+% want to require only one place in this file
+% where the version number is stated,
+% and we also want to ensure that the version
+% number is embedded into every generated file.
+%
+% Now we declare that
+% these files can only be used with \LaTeXe.
+% An appropriate message is displayed if
+% a different \TeX{} format is used.
+%    \begin{macrocode}
+%<*doc|kernel|aps|rmp|revsymb>
+\NeedsTeXFormat{LaTeX2e}[1996/12/01]%
+%</doc|kernel|aps|rmp|revsymb>
+%<kernel>\ProvidesClass{revtex4-2}
+%<aps>\ProvidesFile{aps4-2}
+%<rmp>\ProvidesFile{apsrmp4-2}
+%<10pt>\ProvidesFile{aps10pt4-2}
+%<11pt>\ProvidesFile{aps11pt4-2}
+%<12pt>\ProvidesFile{aps12pt4-2}
+%<revsymb>\ProvidesPackage{revsymb4-2}
+%<*doc>
+\ProvidesFile{revtex4-2.dtx}
+%</doc>
+%<*!package&!options>
+%<version>
+ [2020/10/03 4.2e (https://journals.aps.org/revtex/ for documentation)]% \fileversion
+%</!package&!options>
+%    \end{macrocode}
+% The current class name is remembered in \cmd\class@name.
+% This is something of a klootch, relying as it does on knowledge of the implementation of \cmd\ProvidesPackage.
+%    \begin{macrocode}
+%<kernel>\let\class@name\@gtempa
+%    \end{macrocode}
+%
+% \section{The driver module \texttt{driver}}
+%
+% This module, consisting of the present section,
+% typesets the programmer's documentation,
+% generating the \file{README-REVTEX.txt} and sample document as needed.
+%
+% Because the only uncommented-out lines of code at the beginning of
+% this file constitute the \file{driver} module itself,
+% we can simply typeset the \file{.dtx} file directly,
+% and there is thus rarely any need to
+% generate the ``driver'' {\sc docstrip} module.
+% Module delimiters are nonetheless required so that
+% this code does not find its way into the other modules.
+%
+% The \enve{document} command concludes the typesetting run.
+%
+%    \begin{macrocode}
+%<*doc>
+%    \end{macrocode}
+% The driver uses packages \file{ltxdoc.sty}, \file{ltxdocext.sty}, 
+% \file{hyperref.sty}, and whatever font package has been selected.
+%    \begin{macrocode}
+\documentclass{ltxdoc}
+\RequirePackage{ltxdocext}%
+\let\url\undefined
+\RequirePackage[colorlinks=true,linkcolor=blue]{hyperref}%
+%    \end{macrocode}
+% We ask for the usual indices and glossaries.
+%    \begin{macrocode}
+\CodelineIndex\EnableCrossrefs % makeindex -s gind.ist revtex4
+\RecordChanges % makeindex -s gglo.ist -o revtex4.gls revtex4.glo
+%    \end{macrocode}
+%
+% \subsubsection{Docstrip and info directives}
+%    We use so many {\sc docstrip} modules that we set the
+%    \texttt{StandardModuleDepth} counter to 1.
+%    \begin{macrocode}
+\setcounter{StandardModuleDepth}{1}
+%    \end{macrocode}
+%    The following command retrieves the date and version information
+%    from this file.
+%    \begin{macrocode}
+\expandafter\GetFileInfo\expandafter{\jobname.dtx}%
+%    \end{macrocode}
+%
+% \subsection{The Frontmatter File}
+% As promised above, here is the contents of the frontmatter file. 
+%    \begin{macrocode}
+\begin{filecontents*}{README-REVTEX.tex}
+\title{%
+ The \classname{revtex4-2} document class of the American Physical Society%
+ \protect\thanks{Work under hire to American Physical Society. Version \fileversion\ \copyright\ 2019 American Physical Society}%
+}%
+\author{Arthur Ogawa and Mark Doyle%
+ \protect\thanks{First revision of REV\TeX4.0 (unreleased) by David Carlisle, all released versions of 4.0 and 4.1 by Art Ogawa, 4.2a (unreleased) by Aptara, 4.2b,c by Mark Doyle}%
+}%
+\date{Version \fileversion, dated \filedate}%
+\newcommand\revtex{REV\TeX}
+
+\maketitle
+
+This file embodies the implementation of the APS \revtex\ 4.2 document class
+for electronic submissions to journals.
+
+The distribution point for this work is
+\url{https://journals.aps.org/revtex/},
+which contains fully unpacked, prebuilt runtime files and documentation.
+
+\tableofcontents
+
+\section{Using \protect\revtex}
+
+The file \file{README} has retrieval and installation information.
+
+User documentation is presented separately in \file{auguide.tex}.
+
+The file \file{template.aps} is a boilerplate file. 
+
+\changes{4.0a}{1998/01/16}{Initial version}
+\changes{4.0a}{1998/01/31}{Move after process options, so \cs{clearpage} not in scope of twocolumn}
+\changes{4.0a}{1998/01/31}{Rearrange the ordering so numerical ones come first. AO: David, what does this mean?}
+\changes{4.0a}{1998/01/31}{use font-dependent spacing}
+\changes{4.0a}{1998/01/31}{4.0d had twoside option setting twoside switch to false}
+\changes{4.0a}{1998/01/31}{Move after process options, so the following test works}
+\changes{4.0a}{1998/01/31}{print homepage}
+\changes{4.0a}{1998/01/31}{protect against hyperref revtex kludges which are not needed now}
+\changes{4.0a}{1998/06/10}{multiple preprint commands}
+\changes{4.0a}{1998/06/10}{comma not space between email and homepage}
+\changes{4.0a}{1998/06/10}{single space footnotes}
+\changes{4.0b}{1999/06/20}{First modifications by Arthur Ogawa (mailto:arthur\_ogawa at sbcglobal dot net)}
+\changes{4.0b}{1999/06/20}{Added localization of \cs{figuresname}}
+\changes{4.0b}{1999/06/20}{Added localization of \cs{tablesname}}
+\changes{4.0b}{1999/06/20}{AO: all code for \protect\classoption{10pt} is in this module.}
+\changes{4.0b}{1999/06/20}{AO: all code for \protect\classoption{11pt} is in this module.}
+\changes{4.0b}{1999/06/20}{AO: all code for \protect\classoption{12pt} is in this module.}
+\changes{4.0b}{1999/06/20}{AO: made aps.rtx part of revtex4.dtx}
+\changes{4.0b}{1999/06/20}{AO: remove duplicates}
+\changes{4.0b}{1999/06/20}{call \cs{print@floats}}
+\changes{4.0b}{1999/06/20}{Defer assignment until \cs{AtBeginDocument} time.}
+\changes{4.0b}{1999/06/20}{Defer decision until \cs{AtBeginDocument} time}
+\changes{4.0b}{1999/06/20}{Define three separate environments, defer assignment to \cs{AtBeginDocument} time.}
+\changes{4.0b}{1999/06/20}{Frank Mittelbach, has stated in \protect\classname{multicol}: ``The kernel command \cs{@footnotetext} should not be modified.'' Thus, I have removed David Carlisle's redefinition of that command. Note, however, that later versions of \protect\classname{multicol} do not require this workaround. Belt and suspenders.}%
+\changes{4.0b}{1999/06/20}{Move this ``complex'' option to the front, where it can be overridden by ``simple'' options.}
+\changes{4.0b}{1999/06/20}{New option}
+\changes{4.0b}{1999/06/20}{One-line caption sets flush left.}
+\changes{4.0b}{1999/06/20}{only execute if appropriate}
+\changes{4.0b}{1999/06/20}{Processing delayed to \cs{AtBeginDocument} time}
+\changes{4.0b}{1999/06/20}{Removed invocation of nonexistent class option \protect\classoption{groupauthors} and all other class options that should only be invoked by the document. (Otherwise precedence of class options does not work.)}
+\changes{4.0b}{1999/06/20}{Restore all media size class option of \protect\file{classes.dtx}}
+\changes{4.0b}{1999/06/20}{Stack \cs{preprint} args flush right at right margin.}
+\changes{4.0c}{1999/11/13}{(AO, 115) If three or more preprints specified, set on single line, with commas.}
+\changes{4.0c}{1999/11/13}{(AO, 129) section* within appendix was producing appendixname}
+\changes{4.0c}{1999/11/13}{*-form mandates pagebreak}
+\changes{4.0c}{1999/11/13}{also spelled ``acknowledgements''.}
+\changes{4.0c}{1999/11/13}{Do not put by REVTeX in every page foot}
+\changes{4.0c}{1999/11/13}{grid changes via ltxgrid procedures}
+\changes{4.0c}{1999/11/13}{grid changes with ltxgrid}
+\changes{4.0c}{1999/11/13}{Insert procedure \cs{checkindate}}
+\changes{4.0c}{1999/11/13}{Lose compatability mode.}
+\changes{4.0c}{1999/11/13}{New ltxgrid-based  code, other bug fixes}
+\changes{4.0c}{1999/11/13}{New option ``checkin''}
+\changes{4.0c}{1999/11/13}{Prevent an inner footnote from performing twice}
+\changes{4.0d}{2000/04/10}{Also alter how lists get indented.}
+\changes{4.0d}{2000/04/10}{eprint takes an optional argument, syntactical only in this case.}
+\changes{4.0d}{2000/04/10}{New option}
+\changes{4.0d}{2000/05/10}{More features and bug fixes: compatability with longtable and array packages. Now certainly incompatible with multicol.}
+\changes{4.0d}{2000/05/17}{make longtable trigger the head, too}
+\changes{4.0d}{2000/05/18}{But alternative spelling is deprecated.}
+\changes{4.0e}{2000/09/20}{New option showkeys}
+\changes{4.0e}{2000/11/14}{Bug fixes and minor new features: title block affiliations can have ancillary data, just like authors; clearpage processing revamped, with floats staying in order; widetext ornaments.}
+\changes{4.0e}{2000/11/21}{adornments above and below.}
+\changes{4.0f}{2001/02/13}{Last bug fixes before release.}
+\changes{4.0rc1}{2001/06/17}{Running headers always as if two-sided}
+\changes{4.0rc1}{2001/06/18}{grid changes with push and pop}
+\changes{4.0rc1}{2001/06/18}{grid changes with push and pop}
+\changes{4.0rc4}{2001/07/23}{hyperref is no longer loaded via class option: use a usepackage statement instead}
+\changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+\changes{4.1a}{2008/01/18}{(AO, 451) ``Cannot have more than 256 cites in a document''}%
+\changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+\changes{4.1a}{2008/01/18}{(AO, 460) ``Proper style is "FIG. 1. ..." (no colon)''}%
+\changes{4.1a}{2008/01/18}{(AO, 478) \cs{ds@letterpaper}, so that ``letterpaper really is the default''}%
+\changes{4.1a}{2008/01/18}{(AO, 488) Change processing of options to allow an unused option to specify society and journal}%
+\changes{4.1a}{2008/01/19}{(AO, 461) Change the csname revtex uses from @dotsep to ltxu@dotsep. The former is understood in mu. (What we wanted was a dimension.)}%
+\changes{4.1a}{2008/01/19}{For natbib versions before 8.21, \cs{NAT@sort} was consulted only as natbib was being read in. Now it is fully dynamic.}
+\changes{4.1b}{2008/05/29}{The csname substyle@ext is now defined without a dot (.), to be compatible with \LaTeX usage (see @clsextension and @pkgextension).}
+\changes{4.1b}{2008/06/01}{(AO) Implement bibnotes through \cs{frontmatter@footnote@produce} instead of \cs{bibnotes@sw}}%
+\changes{4.1b}{2008/06/01}{Add option reprint, opposite of preprint, and preferred alternative to twocolumn}
+\changes{4.1b}{2008/06/29}{(AO, 455) Be nice to a list within the abstract (assign \cs{@totalleftmargin}).}
+\changes{4.1b}{2008/06/30}{(AO) Structure the Abstract using the \texttt{bibliography} environment}
+\changes{4.1b}{2008/07/01}{(AO) coordinate \cs{if@twoside} with \cs{twoside@sw}}
+\changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+\changes{4.1b}{2008/07/01}{(AO) No longer need to test \cs{chapter} as of \texttt{natbib} version 8.2}
+\changes{4.1b}{2008/07/01}{(AO) No longer use \cs{secnumarabic@sw}, instead use \cs{setup@secnums}}
+\changes{4.1b}{2008/07/01}{(AO) Provide more diagnostics when \cs{@society} is assigned.}
+\changes{4.1b}{2008/07/01}{(AO) provide option longbibliography}
+\changes{4.1b}{2008/07/01}{Add \cs{@hangfroms@section}}
+\changes{4.1b}{2008/07/01}{Break out \cs{@caption@fignum@sep}}
+\changes{4.1b}{2008/07/01}{Class option galley sets \cs{preprintsty@sw} to false}
+\changes{4.1b}{2008/07/01}{Code relating to new syntax for frontmatter has been placed in \file{ltxfront.dtx}}
+\changes{4.1b}{2008/07/01}{Package textcase is now simply a required package}
+\changes{4.1b}{2008/07/01}{Procedures \cs{@parse@class@options@society} and \cs{@parse@class@options@journal} and friends}
+\changes{4.1b}{2008/07/01}{Read in all required packages together}
+\changes{4.1b}{2008/07/01}{Remove options newabstract and oldabstract}
+\changes{4.1b}{2008/08/01}{Section numbering via procedures \cs{secnums@rtx} and \cs{secnums@arabic}.}
+\changes{4.1b}{2008/08/04}{As with author formatting, rag the right more, and assign \cs{@totalleftmargin}. Also neutralize \cs{def@after@address}.}%
+\changes{4.1b}{2008/08/04}{Rag the right even more: .8\cs{hsize}. Also, assign \cs{@totalleftmargin}.}%
+\changes{4.1b}{2008/08/04}{The \texttt{rmp} journal substyle selects \texttt{groupedaddress} by default.}%
+\changes{4.1b}{2008/08/04}{Use \cs{setup@hook} to initialize all.}
+\changes{4.1c}{2008/08/15}{Document class option longbibliography via \cs{substyle@post}}
+\changes{4.1d}{2009/03/27}{Definition of \cs{	@fnsymbol} follows fixltx2e.sty}
+\changes{4.1e}{2008/06/29}{(AO, 455) be nice to a list within the abstract}
+\changes{4.1f}{2009/07/07}{(AO, 513) Add class option linenumbers: number the lines a la \classname{lineno}}
+\changes{4.1f}{2009/07/07}{(AO, 516) Merged references are separated with a semicolon}
+\changes{4.1f}{2009/07/10}{(AO, 520) Automatically produce \cs{bibliography} command when needed}%
+\changes{4.1f}{2009/07/11}{(AO, 521) Lonely bibliography head}%
+\changes{4.1f}{2009/07/11}{(AO, 522) Warn if software is expired}%
+\changes{4.1f}{2009/07/15}{(AO, 523) Add class option nomerge, to turn off new natbib 8.3 syntax}
+\changes{4.1f}{2009/07/20}{(AO, 524) Makes no sense if citations are superscript numbers and so are footnotes}
+\changes{4.1f}{2009/10/05}{(AO, 530) \cs{@fnsymbol}: Failed to import fixltx2e.sty technology. Return to LaTeX core.}
+\changes{4.1g}{2009/10/07}{(AO, 525) Remove phantom paragraph above display math that is given in vertical mode}%
+\changes{4.1g}{2009/10/07}{(AO, 538) \cs{MakeTextUppercase} inappropriately expands the double backslash}
+\changes{4.1h}{2009/10/09}{(AO) Remove expiry code in the release software}%
+\changes{4.1i}{2009/10/23}{(AO, 541) Defer assignment of \cs{cite} until after natbib loads}
+\changes{4.1j}{2009/10/24}{(AO, 549) Repairing natbib's \cs{BibitemShut} and \cs{bibAnnote}}
+\changes{4.1j}{2009/10/25}{(AO, 545) hypertext capabilities off by default; enable with \classoption{hypertext}}
+\changes{4.1j}{2009/10/25}{(AO, 552) Repair spacing in \cs{onlinecite}}
+\changes{4.1k}{2009/11/06}{(AO, 554) give the \cs{newlabel} command syntax appropriate to the hyperref package}
+\changes{4.1n}{2009/11/06}{(AO, 565) restore 4.0 behavior: invoking class option preprint implies class option preprintnumbers}
+\changes{4.1n}{2009/11/30}{(AO, 566) restore 4.0 behavior: flush column bottoms}
+\changes{4.1n}{2009/12/05}{(AO, 569) Use of \classname{hyperref} interferes with column balancing of last page}%
+\changes{4.1n}{2009/12/09}{(AO, 569) execute the after-last-shipout procedures from within the safety of the output routine}%
+\changes{4.1n}{2010/01/02}{(AO, 571) Interface \cs{set@footnotewidth} for determining the set width of footnotes}%
+\changes{4.1n}{2010/01/02}{(AO, 572) Independent footnote counter for title block. Abstract footnote counter shared with body.}%
+\changes{4.1n}{2009/12/13}{(AO, 573) arrange to load \classname{lineno} after any other packages.}%
+\changes{4.1n}{2010/01/04}{(AO, 575) the default for journal prstper is longbibliography}%
+\changes{4.1n}{2010/01/04}{(AO, 576) In .bst files, remove support for the annote field}%
+\changes{4.1n}{2010/01/02}{(AO) fine-tune spacing above and below widetext}%
+\changes{4.1n}{2010/01/02}{(AO, 571) class file must set \cs{splittopskip}; fine tune \cs{skip}\cs{footins}; \cs{footnoterule} defined in terms of \cs{skip}\cs{footins}}%
+\changes{4.1n}{2010/01/02}{(AO, 572) \cs{@makefntext} and \cs{frontmatter@makefntext} must be defined harmoniously}%
+\changes{4.1o}{2010/02/02}{(AO, 575) Automatically incorporate the (Bib\TeX-generated) .bbl into an explicit \env{thebibliography}}%
+\changes{4.1o}{2010/02/05}{(AO, 549) Remove patch to natbib, which is now at version 8.31a}
+\changes{4.1o}{2010/02/07}{(AO, 578) accommodate the possible space character preceding \cs{BibitemShut}.} 
+\changes{4.1o}{2010/02/05}{(AO, 579) Endnote shall comprise their own Bib\TeX\ entry type: @FOOTNOTE.} 
+\changes{4.1o}{2010/02/10}{(AO, 580) Provide a document class option to turn off production of eprint field in bibliography.} 
+\changes{4.1o}{2010/02/12}{(AO, 580) Control .bst at run time.}%
+\changes{4.1o}{2010/02/09}{(AO, 581) Handle case: merged references, with first ending in a stop character.} 
+\changes{4.1p}{2010/02/24}{(AO, 583) Provide interface to \classname{ltxgrid} \cs{onecolumn@grid@setup} and \cs{twocolumn@grid@setup}} 
+\changes{4.1p}{2010/02/24}{(AO, 584) Per MD, remove trailing space character from each journal abbreviation: it had caused an extraneous space in the .bbl} 
+\changes{4.1q}{2010/04/01}{(AO, 586) When .bbl is pasted into the document, prevent automatic bibliography inclusion.}%
+\changes{4.1q}{2010/04/13}{(AO, 588) Only write \revtex-specific BibTeX .bib data if the .bst style is set by REVTeX.}%
+\changes{4.1r}{2010/06/22}{(AO, 595) Provide \cs{lovname} along with other List of Videos definitions.}%
+\changes{4.2a}{2014/12/31}{(Aptara, MD) Added initial support for SOR and AAPM journals, additional journals for APS, and additional journals and proceedings for AIP, unreleased.}%
+\changes{4.2a}{2014/12/31}{(Aptara) Make prb style to follow other Phys. Rev. journals.}%
+\changes{4.2a}{2014/12/31}{(Aptara) Corrected indentation for tableofcontents appearing along with listoffigure/listoftable.}%
+\changes{4.2a}{2017/11/21}{(MD) Make long bibliography style the default now.}%
+\changes{4.2a}{2017/11/28}{(MD) Add call to normalsize to be a good citizen and allow booktabs.sty to work properly}.%
+\changes{4.2b}{2018/12/26}{(MD) Make titles in bibliography default, prb style to follow other Phys. Rev. journals, add a unified physrev option as well as prx and prapplied options. Corrected indentation for tableofcontents appearing along with listoffigure/listoftable.}%
+\changes{4.2b}{2017/11/21}{(MD) Update options for new titles without "Special Topics" and make prper match style of other journal options}%
+\changes{4.2b}{2017/11/21}{(MD) Add options for new APS journals and a generic physrev option for future-proofing}%
+\changes{4.2b}{2017/11/22}{(MD) Change default to not use a title page - it seems antiquated}%
+\changes{4.2b}{2017/11/22}{(MD) MD - not sure why these parameters were different previously. Made them match except for title.}%
+\changes{4.2b}{2017/11/22}{(MD) PACS are obsolete altogether now}%
+\changes{4.2b}{2018/12/26}{(MD) Improve control over display of e-print ids in bibliography.}%
+
+\end{filecontents*}
+%    \end{macrocode}
+%
+% \subsection{The Document Body}
+%
+% Here is the document body, containing only a
+% \cmd\DocInput\ directive---referring to this very file.
+% This very cute self-reference is a common \classname{ltxdoc} idiom.
+%    \begin{macrocode}
+%%\newcommand\revtex{REV\TeX}% TeXSupport
+\begin{document}%
+\expandafter\DocInput\expandafter{\jobname.dtx}%
+\PrintChanges
+\end{document}
+%    \end{macrocode}
+% And that is the end of the driver for the programmer's documentation.
+%    \begin{macrocode}
+%</doc>
+%    \end{macrocode}
+%
+% \section{Overview}%
+% \revtex\ is a \LaTeXe\ document class, somewhat like a hybrid of 
+% the standard \LaTeX\ \classname{book} and \classname{article} classes.
+%
+% Certain packages are (should be) loaded by this class in any case:
+% \classname{amssymb}, \classname{amsmath}, \classname{bm}, \classname{natbib}.
+% 
+% Certain packages are automatically loaded by this class
+% when a corresponding class option has been invoked:
+% 
+% \begin{tabular}{ll}
+% \textbf{\revtex\ option}&\textbf{package}\\
+% \classoption{amsfonts}&\classname{amsfonts}\\
+% \classoption{amssymb}&\classname{amssymb}\\
+% \classoption{aps}&\classname{overcite}\\
+% \end{tabular}
+%
+% Certain other packages are to be loaded by the
+% document through explicit use of \cmd\usepackage.
+% Some mentioned in the user documentation are
+% \classname{graphicx}, \classname{longtable}, \classname{hyperref}, 
+% and \classname{bm}.
+%
+% Certain commonly used packages are known to be incompatible with
+% \revtex, among them \classname{multicol} and \classname{cite}.
+% If such a package is found to be loaded, \revtex\ issues an error message
+% and halts the job.
+% Halting might be considered severe punishment for loading an incompatible 
+% package, but if we were to proceed, an even weirder error might be encountered
+% further down the road.
+%
+% This document class implements the substyle: a set of mutually
+% exclusive class options that, in this case, allow the 
+% document class to address multiple societies.
+% It also implements a sub-substyle, giving the 
+% journal of the given society.
+% Any society may create a substyle;
+% this file generates one for \classoption{aps}.
+%
+% FIXME: should always load the \classname{graphicx} package. No, allow user to load whichever graphics package is desired.
+% 
+% QUERY: since \classname{amsfonts} and \classname{amssymb} extend
+% syntax, why not load them in any case?
+% 
+% Certain processing occurs at the endgame for reading in \revtex, thereby establishing
+% precedence for assignments to \LaTeX's (and \revtex's) parameters:
+% \begin{enumerate}
+% \item
+%  Figure out which society is operative and read in the indicated \file{.rtx} file.
+% \item
+%  Figure out which journal option is operative and execute the indicated journal command. This may lead to reading in a journal substyle \file{.rtx} file.
+% \item
+%  Figure out which pointsize is operative and execute the indicateded pointsize command. This may lead to reading in a pointsize  \file{.rtx} file.
+% \item
+%  Execute all of the document's options, in the order declared within the document.
+% \item
+%  Read in all required packages (like \classname{natbib}, \classname{amsfonts}, \classname{amssymb}), that were determined by class, society, and journal.
+% \item
+%  The last required package, if existing, is the document's style file, the \file{.rty} file. 
+%  Note that the \file{.rty} file can override the assignments of \revtex, society, journal, and required packages, and even load its own packages.
+%  It can also, via appendations to \cmd\setup@hook, override the setup code itself.
+% \item
+%  Execute all of the setup code accumulated. Such code can be queued by \revtex\ itself, by the society, by the journal, or by the pointsize. 
+% \item
+%  At this point, \revtex\ has completed the process of inputting itself, 
+%  and \LaTeX\ will now execute the \cmd\AtEndOfClass\ procedures.
+% \end{enumerate}
+%
+% \revtex\ will have enqueued code to execute at \cmd\AtBeginDocument\ time,
+% in two different queues. 
+% \cmd\document@inithook\ executes immediately upon encountering the \cmd\begin\env{document} statement, 
+% \cmd\class@documenthook\ at the end of all the code enqueued via \cmd\AtBeginDocument. 
+% \begin{enumerate}
+% \item
+%  Install procedures to execute at the very end of the class's
+%  \cmd\AtBeginDocument\ processing, such as
+%  \begin{enumerate}
+%  \item
+%   closing out the page grid
+%  \item
+%   putting out the LastPage label.
+%  \item
+%   issuing a \cmd\bibliographystyle\ command, based on the value set
+%   by the society substyle.
+%  \item
+%   setting default values for parameters used in the document.
+%FIXME: differentiate between class's parameters that can wait until
+% they are used in the document, and parameters that are used at \cmd\AtBeginDocument\ time.
+%  \end{enumerate}
+% \item
+%  Install procedures to execute the very last at \cmd\AtEndDocument\ time,
+%  such as the \cmd\clearpage\ processing.
+% \end{enumerate}
+%
+% Certain events are optionally scheduled for \cmd\AtBeginDocument\ time:
+% \begin{enumerate}
+% \item
+%  Setting default values for the Booleans and for other procedures used in formatting.
+% \item
+%  In response to class options options, adjusting parameters and procedures used in formatting.
+% \item
+%  Implementing the \classoption{eqsecnum} option, if required.
+% \item
+%  Setting the state engine for data commands.
+% \item
+%  Memorizing procedures for later use.
+% \item
+%  Setting type size and area, for use by later calculations.
+% \end{enumerate}
+%
+% Certain events are scheduled for \cmd\class@enddocumenthook\ time:
+% \begin{enumerate}
+% \item
+%  Print out the migrated floats or the end notes, if needed.
+% \item
+%  Close out the page grid.
+% \item
+%  Label the last page of the document
+% \item
+%  (\classname{natbib}) prepare to read in the \file{.aux} file.
+% \end{enumerate}
+%
+% \section{Writing journal-specifc extensions to \revtex}
+%
+% With this version of \revtex, we introduce a somewhat different
+% scheme for adapting \revtex\ to the needs of a specific journal.
+%
+% To create a journal substyle, you create new class options in 
+% \revtex\ for the society, say \classoption{osa}, and any of that society's journals,
+% one of which is, say, \classoption{josaa},
+% using the code for the APS as a guide.
+% In particular, each of your new options should separately define \cmd\@society\
+% and \cmd\@journal. That for the former will be the same for
+% all options relating to a particular society.
+%
+% Then, for the society, you create a corresponding \file{.rtx}
+% file, in our case \file{osa.rtx}.
+% Within that file, you override procedures and parameter assignments as you see fit.
+% Ideally they will be generally applicable to all of that society's
+% journals (see the file \file{aps.rtx} for a realization of this scheme).
+% Also within that file, you include a 
+% section of code for each journal, that for josaa looks like:
+% \begin{verbatim}
+% \@ifx{\@journal\journal@josaa}{%
+% <code specific to the josaa>
+% }{}%
+% \end{verbatim}
+% 
+% Thus far, the scheme is similar to that used in \revtex\ 3.1.
+% However, the new scheme does differ from the old in that 
+% the \file{.rtx} file should define no syntactical extensions
+% to \revtex.
+%
+% \section{The \classname{revtex4} Document Class}
+% Above, we took
+% advantage of 1) the \LaTeX\ definition of \cmd\ProvidesPackage\ and
+% 2) that the line of code immediately afterwards follows the \cmd\ProvidesClass\ statement above. 
+%    \begin{macrocode}
+%<*kernel>
+%    \end{macrocode}
+%
+% Print a banner in the log:
+%    \begin{macrocode}
+\GenericInfo{}{\space
+ Copyright (c) 2019 American Physical Society.^^J
+ mailto:revtex@aps.org^^J
+ Licensed under the LPPL:^^Jhttp://www.ctan.org/tex-archive/macros/latex/base/lppl.txt^^J
+ Arthur Ogawa <arthur_ogawa at sbcglobal dot net>^^J
+ Based on work by David Carlisle <david at dcarlisle.demon.co.uk>^^J
+ Version (4.2d,4.2e): Modified by Mark Doyle and Phelype Oleinik^^J
+ \@gobble
+}%
+%    \end{macrocode}
+%
+% \subsection{Compatibility Processing}
+%
+% If the document has \cmd\documentstyle|{revtex4}|,
+% then, instead of attempting to run in compatability mode,
+% just complain and exit.
+% \changes{4.0c}{1999/11/13}{Lose compatability mode.}
+%    \begin{macrocode}
+\if@compatibility    
+  \edef\reserved@a{\errhelp{%
+   Change your \string\documentstyle\space statement to
+   \string\documentclass\space and rerun.
+  }}\reserved@a
+  \errmessage{You cannot run \class@name\space in compatability mode}%
+  \expandafter\@@end
+\fi
+%    \end{macrocode}
+%
+%
+% \section{Extensions to the \LaTeX\ Kernel}
+%
+%    \begin{macrocode}
+%</kernel>
+%    \end{macrocode}
+%
+% Here, we incorporate the utility, frontmatter, and page grid packages.
+% The \classname{ltxutil}, \classname{ltxfront}, and \classname{ltxgrid} source are distributed with 
+% \revtex.
+%
+% Here begins the \file{options} \textsc{docstrip} module.
+%    \begin{macrocode}
+%<*options>
+%    \end{macrocode}
+%
+% \subsection{Hooks}
+%
+% \begin{macro}{\setup@hook}
+% The procedure 
+% \cmd\setup@hook\
+% serves as the vehicle for all code that 
+% gives values to the class's parameters once all the 
+% society, journal, options, and packages have been processed. 
+%
+% Arrange for journal substyles to set their own default values.
+%    \begin{macrocode}
+\let\setup@hook\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% After preamble processing is complete,
+% detect whether package \classname{longtable} has been loaded and patch it.
+%    \begin{macrocode}
+\appdef\document@inithook{%
+ \switch@longtable
+ \let\LT@makecaption\LT@makecaption@rtx
+}%
+%    \end{macrocode}
+%
+% \begin{macro}{\LT@makecaption}
+% We override the caption processing method of the \classname{longtable} package:
+% space below the caption is created via strut instead of whitespace.
+%    \begin{macrocode}
+\def\LT@makecaption@rtx#1#2#3{%
+  \LT@mcol\LT@cols c{%
+    \hbox to\z@{%
+     \hss
+     \parbox[t]\LTcapwidth{%
+      \sbox\@tempboxa{#1{#2: }#3\unskip\nobreak\vrule\@width\z@\@height\z@\@depth .5\baselineskip}%
+      \ifdim\wd\@tempboxa>\hsize
+        #1{#2: }#3\unskip\nobreak\vrule\@width\z@\@height\z@\@depth .5\baselineskip
+      \else
+        \hbox to\hsize{\hfil\box\@tempboxa\hfil}%
+      \fi
+      \endgraf
+     }%
+     \hss
+    }%
+  }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\robust@boldmath}
+% Robustify the \cmd\boldmath command. 
+% If Team \LaTeX\ (or any package) ever gets around to fixing this problem, 
+% we will bow out. (This fix relates to bug \#394.)
+%    \begin{macrocode}
+\def\protectdef@boldmath{%
+ \expandafter\@ifnotrelax\csname boldmath \endcsname{}{%
+  \class@info{Robustifying \string\LaTeX's \string\boldmath\space command}%
+  \expandafter\let\csname boldmath \endcsname\boldmath
+  \expandafter\def\expandafter\boldmath\expandafter{\expandafter\protect\csname boldmath \endcsname}%
+ }%
+}%
+\appdef\document@inithook{%
+ \protectdef@boldmath
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \section{Compatability with the geometry package}
+%
+% The \classname{geometry} package of Hideo Umeki provides a way to 
+% specify the metrics of the media and page layout.
+% We want to ensure that \revtex\ does not foreclose on the use of 
+% this or any other such package, nor to interfere with
+% explicit assignments of such metric parameters within the 
+% document preamble.
+% 
+% The \LaTeX\ parameters (resp. \TeX\ primitives) set by \classname{geometry} are:
+% \cmd\paperwidth, \cmd\paperheight, 
+% \cmd\textwidth, \cmd\textheight, 
+% \cmd\topmargin, \cmd\headheight, \cmd\headsep, 
+% \cmd\footskip, \cmd\skip\cmd\footins, 
+% \cmd\marginparwidth, \cmd\marginparsep, 
+% \cmd\oddsidemargin, \cmd\evensidemargin, 
+% \cmd\columnsep, 
+% \cmd\hoffset, \cmd\voffset, \cmd\mag, 
+% \cmd\if@twocolumn, \cmd\if@twoside, \cmd\if@mparswitch, \cmd\if@reversemargin, 
+%
+% \revtex's assignments can be overridden by 
+% any package or other statement in the document preamble, 
+% so it should be compatible. 
+%
+%FIXME: one parameter is rendered semantically void (by \file{ltxgrid.dtx}): 
+% \cmd\if@twocolumn. 
+%
+% \section{Options}\label{sec:options}%
+%
+% \subsection{Define Booleans Used in Options}%
+% The following Booleans are used within the document class to
+% allow the document or the substyle to make selections
+% of formatting.
+% An explicit document class option overrides an assignment made by a substyle.
+%
+% \subsection{Declare Options}%
+%
+% \subsubsection{Checkin: for Editorial Use}%
+% A document class option declaring that the document is being processed by the 
+% editorial staff.
+%
+% This option should:
+% \begin{itemize}
+% \item
+% put date in footer along with folio
+% \item
+% Have the effect of selecting the \classoption{preprint} class option.
+% \item
+% Have the effect of selecting the \classoption{showpacs} class option.
+% \item
+% specify that when a float is placed h or H, it will be allowed to break over pages.
+% (Note: be sure that if the enclosed \env{tabular} has an optional argument, you change it to [v], or remove it entirely.)
+% \end{itemize}
+% \changes{4.0c}{1999/11/13}{New option ``checkin''}
+%    \begin{macrocode}
+\DeclareOption{checkin}{%
+  \@booleantrue\dateinRH@sw
+  \@booleantrue\preprintsty@sw
+  \def\@pointsize{12}%
+  \@booleantrue\showPACS@sw
+  \@booleantrue\showKEYS@sw
+  \def\fp@proc@h{\allow@breaking@tables}%
+  \def\fp@proc@H{\allow@breaking@tables}%
+}%
+\@booleanfalse\dateinRH@sw
+\def\checkindate{\dateinRH@sw{{\tiny(\today)}}{}}%
+\def\allow@breaking@tables{%
+ \def\array@default{v}% tabular can break over pages
+ \@booleanfalse\floats@sw % table can break over pages
+}%
+%    \end{macrocode}
+%
+% \subsubsection{Preprint Style}%
+%
+% \begin{macro}{\preprintsty@sw}
+% The boolean \cmd\preprintsty@sw\ signifies that 
+% the document is to be formatted in preprint style.
+% \changes{4.0a}{1998/01/31}{Rearrange the ordering so numerical ones come first. AO: David, what does this mean?}
+% \changes{4.0a}{1998/06/10}{comma not space between email and homepage}
+% \changes{4.0b}{1999/06/20}{Move this ``complex'' option to the front, where it can be overridden by ``simple'' options.}
+% \changes{4.1b}{2008/06/01}{Add option reprint, opposite of preprint, and preferred alternative to twocolumn}
+%    \begin{macrocode}
+\DeclareOption{preprint}{%
+ \@booleantrue\preprintsty@sw
+ \ExecuteOptions{12pt}%
+}%
+\DeclareOption{reprint}{%
+\@booleanfalse\preprintsty@sw
+\@booleantrue\twocolumn@sw
+ \ExecuteOptions{10pt}%
+}%
+\DeclareOption{manuscript}{%
+ \class@warn{Document class option manuscript is obsolete; use preprint instead}%
+ \ExecuteOptions{preprint}%
+}%
+\@booleanfalse\preprintsty@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\showPACS@sw}
+% \begin{macro}{\showKEYS@sw}
+% If \cmd\showPACS@sw\ is true, print the PACS information in the title block,
+% otherwise not.
+% Similarly for \cmd\showKEYS@sw\ and the keywords.
+% \subsubsection{Showing PACS and keywords}%
+% \changes{4.0b}{1999/06/20}{New option}
+% \changes{4.0e}{2000/09/20}{New option showkeys}
+%    \begin{macrocode}
+\DeclareOption{showpacs}{%
+  \@booleantrue\showPACS@sw
+}%
+\DeclareOption{noshowpacs}{%
+  \@booleanfalse\showPACS@sw
+}%
+\DeclareOption{showkeys}{%
+  \@booleantrue\showKEYS@sw
+}%
+\DeclareOption{noshowkeys}{%
+  \@booleanfalse\showKEYS@sw
+}%
+\@booleanfalse\showPACS@sw
+\@booleanfalse\showKEYS@sw
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Balance the last page when in two-column page grid}%
+%
+% \begin{macro}{\balancelastpage@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% If we are in a two-column page grid, we may wish to balance the columns
+% of the last page. This will be done automatically if the 
+% \classoption{twocolumn} document class option is chosen.
+% This action will be turned off by the \classoption{nobalancelastpage}.
+% A complementary class option, \classoption{balancelastpage} is also provided.
+%    \begin{macrocode}
+\DeclareOption{balancelastpage}{%
+  \@booleantrue\balancelastpage@sw
+}%
+\DeclareOption{nobalancelastpage}{%
+  \@booleanfalse\balancelastpage@sw
+}%
+\@booleantrue\balancelastpage@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Showing preprint numbers}%
+%
+% \begin{macro}{\preprint@sw}
+% \changes{4.0d}{2000/04/10}{New option}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% \changes{4.1n}{2009/11/06}{(AO, 565) restore 4.0 behavior: default value of \cs{preprint@sw} follows \cs{preprintsty@sw}}
+% The boolean \cmd\preprint@sw\ signifies that 
+% the preprints (cf. \cmd\preprint) are to be formatted (usually on the title page).
+% The option \classoption{preprintnumbers} declares to do so,
+% \classoption{nopreprintnumbers} declares not to; 
+% the default is to follow \cmd\preprintsty@sw. 
+%    \begin{macrocode}
+\DeclareOption{nopreprintnumbers}{\@booleanfalse\preprint@sw}%
+\DeclareOption{preprintnumbers}{\@booleantrue\preprint@sw}%
+\appdef\setup@hook{%
+ \@ifxundefined\preprint@sw{\let\preprint@sw\preprintsty@sw}{}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Hypertext Option}%
+%
+% \changes{4.0a}{1998/01/31}{protect against hyperref revtex kludges which are not needed now}
+% \changes{4.0b}{1999/06/20}{Move this ``complex'' option to the front, where it can be overridden by ``simple'' options.}
+% \changes{4.0rc4}{2001/07/23}{hyperref is no longer loaded via class option: use a usepackage statement instead}
+%    \begin{macrocode}
+\DeclareOption{hyperref}{%
+%    \end{macrocode}
+% The following code had been commented out, it is now truly a comment:
+%    \begin{verbatim}
+%\AtEndOfClass{%
+% \begingroup
+%  \edef\@tempa{%
+%   \let
+%   \noexpand\@clsextension
+%   \noexpand\@empty
+%   \noexpand\RequirePackage{hyperref}%
+%   \def\noexpand
+%   \@clsextension{\@clsextension}%
+%  }%
+%  \expandafter
+% \endgroup
+% \@tempa
+%}%
+% \def\@pointsize{10}%
+%    \end{verbatim}
+%
+% If you have a hyper-foo enabled browser you may prefer this format
+% which does not print the URL for the home page, but just makes the
+% name a link, but by default print it so it works on paper.
+% \changes{4.0a}{1998/01/31}{print homepage}
+%
+%    \begin{macrocode}
+ \class@warn{Class option "hyperref" is no longer supported.^^JEmploy \string\usepackage{hyperref} instead}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{Type Size}%
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% Use \cmd\@pointsize|=10| rather than \cmd\@ptsize|=0| to allow easy extensions
+% to 9pt or whatever. 
+% Note: the three alternatives are mutually exclusive. 
+%
+% At this point, the parameter \cmd\@pointsize\ is set to \cmd\undefined:
+% a society \emph{must} give it a definition.
+%    \begin{macrocode}
+\DeclareOption{10pt}{\def\@pointsize{10}}%
+\DeclareOption{11pt}{\def\@pointsize{11}}%
+\DeclareOption{12pt}{\def\@pointsize{12}}%
+\let\@pointsize\@undefined
+%    \end{macrocode}
+%
+% \subsubsection{Media Size}%
+%
+% \begin{macro}{\paperheight}
+% \begin{macro}{\paperwidth}
+% \changes{4.0b}{1999/06/20}{Restore all media size class option of \protect\file{classes.dtx}}
+%    \begin{macrocode}
+\DeclareOption{a4paper}{%
+    \setlength\paperheight {297mm}%
+    \setlength\paperwidth  {210mm}%
+}%
+\DeclareOption{a5paper}{%
+    \setlength\paperheight {210mm}%
+    \setlength\paperwidth  {148mm}%
+}%
+\DeclareOption{b5paper}{%
+    \setlength\paperheight {250mm}%
+    \setlength\paperwidth  {176mm}%
+}%
+\DeclareOption{letterpaper}{%
+    \setlength\paperheight {11in}%
+    \setlength\paperwidth  {8.5in}%
+}%
+\DeclareOption{legalpaper}{%
+    \setlength\paperheight {14in}%
+    \setlength\paperwidth  {8.5in}%
+}%
+\DeclareOption{executivepaper}{%
+    \setlength\paperheight {10.5in}%
+    \setlength\paperwidth  {7.25in}%
+}%
+\DeclareOption{landscape}{%
+    \setlength\@tempdima   {\paperheight}%
+    \setlength\paperheight {\paperwidth}%
+    \setlength\paperwidth  {\@tempdima}%
+}%
+%    \end{macrocode}
+%
+% \changes{4.1a}{2008/01/18}{(AO, 478) \cs{ds@letterpaper}, so that ``letterpaper really is the default''}%
+% Effectively select \classoption{letterpaper}. 
+%    \begin{macrocode}
+\ds@letterpaper
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Bibnotes}%
+%
+% \begin{macro}{\frontmatter@footnote@produce}
+% Frontmatter footnotes result from frontmatter commands like
+% \cmd\email, \cmd\homepage, \cmd\altaffiliation, and \cmd\thanks.
+% The default for \cmd\frontmatter@footnote@produce\ is
+% \cmd\frontmatter@footnote@produce@footnote, which formats the frontmatter footnotes
+% at the foot of the title page. The \classoption{bibnotes} class option
+% defers them to the bibliography.
+% \changes{4.1b}{2008/06/01}{(AO) Implement bibnotes through \cs{frontmatter@footnote@produce} instead of \cs{bibnotes@sw}}%
+%    \begin{macrocode}
+\DeclareOption{bibnotes}{\let\frontmatter@footnote@produce\frontmatter@footnote@produce@endnote}%
+\DeclareOption{nobibnotes}{\let\frontmatter@footnote@produce\frontmatter@footnote@produce@footnote}%
+\let\frontmatter@footnote@produce\frontmatter@footnote@produce@footnote
+\appdef\class@enddocumenthook{\auto@bib}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Footinbib}%
+%
+% \begin{macro}{\footinbib@sw}
+% The boolean \cmd\footinbib@sw\ signifies that 
+% text footnotes are to be set in the bibliography, as endnotes.
+% 
+% The document may set the value one way or the other via
+% the following two class options.
+%    \begin{macrocode}
+\DeclareOption{footinbib}{\@booleantrue\footinbib@sw}
+\DeclareOption{nofootinbib}{\@booleanfalse\footinbib@sw}
+%    \end{macrocode}
+% The default value is \cmd\false@sw, and the society or journal
+% may override the default. 
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+%    \begin{macrocode}
+\@booleanfalse\footinbib@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{altaffilletter}%
+% 
+% \begin{macro}{\altaffilletter@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% Determine the procedure \cmd\thefootnote\ used in frontmatter: 
+% the footnote symbol used in titlepage footnotes.
+%     \begin{macrocode}
+\DeclareOption{altaffilletter}{\@booleantrue\altaffilletter@sw}%
+\DeclareOption{altaffilsymbol}{\@booleanfalse\altaffilletter@sw}%
+\@booleanfalse\altaffilletter@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{superbib}%
+%
+% \begin{macro}{\place@bibnumber}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The procedure \cmd\place@bibnumber\ produces the number
+% at the head of the \cmd\bibitem, in the bibliography.
+% By default, it has the \cmd\bibnumfmt\ meaning assigned by the \classname{natbib} package.
+% It may be overridden by society, journal, or by the document options.
+%
+%     \begin{macrocode}
+\DeclareOption{superbib}{%
+ \let\place@bibnumber\place@bibnumber@sup
+}%
+\def\place@bibnumber{\NATx@bibnumfmt}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\place@bibnumber@sup}
+% \begin{macro}{\place@bibnumber@inl}
+% For producing the \cmd\bibitem\ device,
+% we define two procedures to select from.
+%
+% Note that we could have used \classname{natbib}'s \cmd\ifNAT@super\
+% switch, but it does not allow for altering the meaning of \cmd\bibnumfmt.
+%    \begin{macrocode}
+\def\place@bibnumber@sup#1{\textsuperscript{#1}}%
+\def\place@bibnumber@inl#1{[#1]}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{citeautoscript}%
+% \begin{macro}{\citeautoscript@sw}
+% This class option allows you to automatically accomodate a change from non-superscripted, numbered references
+% to superscripted, bunmbered references.
+%
+% Note: you should always mark up your document with the assumption that references are \emph{not} going to be superscripted.
+% Otherwise this option has no hope of working properly.
+%
+%     \begin{macrocode}
+\DeclareOption{citeautoscript}{\@booleantrue\citeautoscript@sw}%
+\@booleanfalse\citeautoscript@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Variants on the Bibliography Style}%
+% \changes{4.1b}{2008/07/01}{(AO) provide option longbibliography}
+%
+% \revtex\ anticipates that a society or journal will provide two related Bib\TeX bibliography style variants,
+% designating one as the default.
+% A pair of document class options \classoption{longbibliography} and \classoption{nolongbibliography}
+% allows the user to explicitly select between them. 
+% \begin{macro}{\longbibliography@sw}
+%
+%\changes{4.2a}{2017/11/21}{(MD) Make long bibliography style the default now.}
+% \revtex's default for \cmd\longbibliography@sw\ is \cmd\true@sw.
+%
+%     \begin{macrocode}
+\DeclareOption{longbibliography}{\@booleantrue\longbibliography@sw}%
+\DeclareOption{nolongbibliography}{\@booleanfalse\longbibliography@sw}%
+\@booleantrue\longbibliography@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\eprint@enable@sw}
+% \changes{4.1o}{2010/02/10}{(AO, 580) Provide a document class option to turn off production of eprint field in bibliography.} 
+%
+% The document class options \classoption{eprint} and \classoption{noeprint}
+% give the user the ability to turn off production of the \texttt{eprint} field in the bibliography. 
+%     \begin{macrocode}
+\DeclareOption{eprint}{\@booleantrue\eprint@enable@sw}%
+\DeclareOption{noeprint}{\@booleanfalse\eprint@enable@sw}%
+\@booleantrue\eprint@enable@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Simplex/Duplex Pages}%
+%
+% \begin{macro}{\twoside@sw}
+% \changes{4.1b}{2008/07/01}{(AO) coordinate \cs{if@twoside} with \cs{twoside@sw}}
+% The flag \cmd\twoside@sw\ signifies that the document is to be 
+% formatted for duplex printing.
+% After the preamble is processed, we align the value
+% of the kernel \cmd\newif\ switch \cmd\if@twoside\ 
+% to that of \cmd\twoside@sw. 
+% \cmd\if@twoside\ itself is used in the kernel's
+% \cmd\cleardoublepage\ and \cmd\@outputpage\ procedures.
+%    \begin{macrocode}
+\@booleanfalse\twoside@sw
+\appdef\document@inithook{%
+ \twoside@sw{\@twosidetrue}{\@twosidefalse}%
+}%
+%    \end{macrocode}
+% \changes{4.0a}{1998/01/31}{4.d had twoside option setting twoside switch to false}
+% The complementary options \classoption{twoside} and \classoption{oneside}
+% assert formatting for duplex or simplex printing, respectively.
+% At the same time, we arrange for the selection of the page grid 
+% with respect to the marginal column:
+% Because \cmd\if@reversemargin\ remains default (false),
+% if duplex printing, this column will always be on the (right),
+% if simplex printing, it will always be on the (outside).
+% QUERY: correct choice?
+%FIXME: assign \cmd\if@mparswitch\ later (and protect the assignment, too). 
+%    \begin{macrocode}
+\DeclareOption{twoside}{\@booleantrue \twoside@sw\@mparswitchfalse}%
+\DeclareOption{oneside}{\@booleanfalse\twoside@sw\@mparswitchtrue}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Two-Column Page Grid}%
+%
+% \begin{macro}{\twocolumn@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% \changes{4.1p}{2010/02/24}{(AO, 583) Provide interface to \classname{ltxgrid} \cs{onecolumn@grid@setup} and \cs{twocolumn@grid@setup}} 
+% The flag \cmd\twocolumn@sw\ signifies that the document is to be 
+% formatted in the two-column page grid.
+%
+% If no options relating to page grid are invoked by 
+% \cmd\AtBeginDcoument\ time, we set default values.
+% Up to that point, the class can check if \cmd\twocolumn@sw\
+% is \cmd\undefined\ to see if any related options have been invoked.
+%
+% \classoption{onecolumn} specifies one-column page grid.
+% The \classoption{twocolumn} class option employs the standard mechanism for
+% changing the column grid: the \classname{ltxgrid} package.
+%    \begin{macrocode}
+\DeclareOption{onecolumn}{\@booleanfalse\twocolumn@sw}%
+\DeclareOption{twocolumn}{\@booleantrue\twocolumn@sw}%
+\@booleanfalse\twocolumn@sw
+%    \end{macrocode}
+% The column grid is determined by the state of the switch \cmd\twocolumn@sw
+% and is effected at \cmd\class@documenthook\ time.
+% The society or journal file may re-define \cmd\select@column@grid\ 
+% to accomodate, e.g., more than two choices for the page grid. 
+%
+% Note that \cmd\open@column@two\ adds items to the Main Vertical List, 
+% so constitutes the true beginning of the document.
+%
+% Note also that if the selected column grid is a one-column grid, 
+% there is nothing to do, because \classname{ltxgrid} has already
+% set that up via \cmd\@begindocumenthook.
+%    \begin{macrocode}
+\def\select@column@grid{%
+ \twocolumn@sw{%
+  \twocolumn@grid@setup
+  \open@twocolumn
+ }{%
+  \onecolumn@grid@setup
+%    \end{macrocode}
+%    \begin{verbatim}
+% \open@onecolumn
+%    \end{verbatim}
+%    \begin{macrocode}
+ }%
+}%
+\appdef\class@documenthook{%
+ \select@column@grid
+}%
+%    \end{macrocode}
+%
+% \end{macro}
+%
+% \begin{macro}{\clear@document}
+% \changes{4.1n}{2009/12/05}{(AO, 569) Use of \classname{hyperref} interferes with column balancing of last page}%
+%
+% We install into \cmd\class@enddocumenthook\ 
+% a trap for the procedure \cmd\clearpage\ that attempts to end the current page.
+% This procedure needs to be headpatched with \cmd\close@column\ to end the current page grid. 
+%
+% This procedure is executed after all typesetting is complete
+% i.e., after items like \cmd\printtables, as well as all commands queued up by \cmd\AtEndDocument. 
+%
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \let\clearpage@ltx\clearpage
+ \prepdef\clear@document{\let\clearpage\clearpage@ltx\let\clear@document\@empty\close@column}%
+ \appdef\class@documenthook{%
+  \appdef\class@enddocumenthook{%
+   \let\clearpage\clear@document
+  }%
+ }%
+}%
+%    \end{macrocode}
+%
+% \end{macro}
+%
+% \begin{macro}{\authoryear@sw}
+% \changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+% The boolean \cmd\authoryear@sw\ signifies that we are to use author-year citations rather than numerical citations.
+% 
+% The \classoption{author-year} class option selects ``'author-year'' citations;  
+% \classoption{numerical} selectes ``numerical'' citations.
+% The former is the default.
+%    \begin{macrocode}
+\DeclareOption{author-year}{\@booleantrue\authoryear@sw}%
+\DeclareOption{numerical}{\@booleanfalse\authoryear@sw}%
+\@booleanfalse\authoryear@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\galley@sw}
+% The boolean \cmd\galley@sw\ signifies that 
+% the document is to be formatted in galley style.
+%
+% Asserting both \cmd\galley@sw\ and \cmd\preprintsty@sw\ 
+% may produce strange formatting results, but it is not illegal.
+% However, it \emph{is} illegal to assert galley and any 
+% twocolumn option.
+%    \begin{macrocode}
+%    \end{macrocode}
+% \classoption{galley} emulates setting the galleys of
+% a two-column journal.
+% CHANGED: this option should effectively set \cmd\preprintsty@sw\ false.
+% NOTE: it makes no sense to assert both galley and twocolumn.
+% \changes{4.1b}{2008/07/01}{Class option galley sets \cs{preprintsty@sw} to false}
+% 
+%    \begin{macrocode}
+\DeclareOption{galley}{%
+  \ExecuteOptions{onecolumn}%
+  \@booleantrue\galley@sw
+  \@booleanfalse\preprintsty@sw
+  \appdef\setup@hook{%
+    \advance\textwidth-\columnsep
+    \textwidth.5\textwidth
+  }%
+}%
+\@booleanfalse\galley@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{raggedbottom or flushbottom}%
+% \begin{macro}{\raggedcolumn@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The class options \classoption{raggedbottom} and \classoption{flushbottom} determine whether the columns (page)
+% are ragged bottom or flush bottom.
+% Note that we do not select a default here; that is done by the journal substyle.
+%    \begin{macrocode}
+\DeclareOption{raggedbottom}{\@booleantrue\raggedcolumn@sw}
+\DeclareOption{flushbottom}{\@booleanfalse\raggedcolumn@sw}
+\@booleanfalse\raggedcolumn@sw
+\appdef\setup@hook{%
+ \raggedcolumn@sw{\raggedbottom}{\flushbottom}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{tightenlines}%
+%
+% This class option specifies that standard leading 
+% is to be used to set the type.
+% If lacking, the leading will be loose.
+%
+% \begin{macro}{\tightenlines@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The boolean \cmd\tightenlines@sw\ signifies that 
+% the leading is to be made standard amount.
+% If false, it means that the leading is to be set extra open.
+% Has no effect on 10pt size option.
+%
+%    \begin{macrocode}
+\DeclareOption{tightenlines}{\@booleantrue\tightenlines@sw}
+\@booleanfalse\tightenlines@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{lengthcheck}%
+%
+% \begin{macro}{\lengthcheck@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The flag \cmd\lengthcheck@sw\ signifies that 
+% the length checking is in effect.
+% It is up to the individual journal substyle 
+% to alter its formatting accordingly.
+%    \begin{macrocode}
+\@booleanfalse\lengthcheck@sw
+%    \end{macrocode}
+% This class option specifies that the formatted document 
+% should approach as closely as possible the
+% formatting of an actual journal article 
+% to facilitate the author's performance of a length check.
+%
+%FIXME: society or journal may have its own definition of this option.
+%    \begin{macrocode}
+\DeclareOption{lengthcheck}{%
+ \@booleantrue\lengthcheck@sw
+ \ExecuteOptions{reprint}%
+}%
+%    \end{macrocode}
+% In addition, if length checking is in effect, we will enable 
+% the tally of text length. 
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \lengthcheck@sw{\@booleantrue\tally@box@size@sw}{}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Draft and Final}%
+%
+% \begin{macro}{\draft@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The flag \cmd\draft@sw\ signifies that the document is to be 
+% formatted in draft mode. 
+%
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \draft@sw{\overfullrule 5\p@}{\overfullrule\z@}%
+}%
+%    \end{macrocode}
+%
+% Certain packages may pay attention to the 
+% class option \classoption{draft} that sets this Boolean.
+%    \begin{macrocode}
+\DeclareOption{draft}{\@booleantrue\draft@sw}%
+\DeclareOption{final}{\@booleanfalse\draft@sw}%
+\@booleanfalse\draft@sw
+%    \end{macrocode}
+%
+% \end{macro}
+%
+% \subsubsection{eqsecnum}%
+%
+% \begin{macro}{\eqsecnum@sw}
+% The flag \cmd\eqsecnum@sw\ signifies that equations are to be 
+% numbered with the section, e.g., ``Eq. (2.13)''.
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \eqsecnum@sw{%
+  \@addtoreset{equation}{section}%
+  \def\theequation@prefix{\arabic{section}.}%
+ }{}%
+}%
+%    \end{macrocode}
+%
+% The \classoption{eqsecnum} class option signifies that equations are
+% to be numbered within sections.
+%    \begin{macrocode}
+\DeclareOption{eqsecnum}{\@booleantrue\eqsecnum@sw}%
+\@booleanfalse\eqsecnum@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{secnumarabic}%
+% \changes{4.1b}{2008/07/01}{(AO) No longer use \cs{secnumarabic@sw}, instead use \cs{setup@secnums}}
+% The \classoption{secnumarabic} class option signifies that sectioning commands are
+% to be numbered arabic: 
+% the procedure \cmd\secnums@arabic\ is executed as the default. 
+% Otherwise, the procedure \cmd\secnums@rtx\ determines things. 
+% The society or journal may redefine either procedure,
+% and may change the definition of \cmd\setup@secnums\ itself, 
+% thereby establishing a different default. 
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \setup@secnums
+}%
+\DeclareOption{secnumarabic}{%
+ \def\setup@secnums{\secnums@arabic}%
+}%
+\def\setup@secnums{\secnums@rtx}%
+%    \end{macrocode}
+% The code that defines \cmd\secnums@rtx\ and \cmd\secnums@arabic\ appears
+% in Section~\ref{sec:secnumarabic}.
+%
+% \begin{macro}{fleqn}
+% FIXME: model fleqn after amsfonts. I no longer understand why I said this.
+% \file{fleqn.clo} is not a package, so it can simply be \cmd\input. 
+%    \begin{macrocode}
+\DeclareOption{fleqn}{%
+ \input{fleqn.clo}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{floats/endfloats}%
+%
+% \begin{macro}{\floats@sw}
+% \begin{macro}{\floatp@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The Boolean \cmd\floats@sw\ signifies that floats are to be floated;
+% if false, that floats are to be deferred to the end of the document.
+% By default, the former.
+% Note that the state of this Boolean is to be changed by 
+% the document class in response to user-selected options.
+% 
+% This boolean and the assignment of its default value is done by
+% the \classname{ltxutil} package.
+%
+% The Boolean \cmd\floatp@sw\ signifies that endfloats are to be set one per page;
+% if false, that endfloats are to be set with multiple floats per page permitted.
+% By default, the latter.
+% Note that the state of this Boolean is to be changed by 
+% the document class in response to user-selected options.
+% The default is established here.
+%
+% These options control, via the Boolean \cmd\floats@sw, 
+% whether floats are to be migrated to the end of the document.
+%    \begin{macrocode}
+\DeclareOption{floats}{\@booleantrue\floats@sw\@booleanfalse\floatp@sw}
+\DeclareOption{endfloats}{\@booleanfalse\floats@sw\@booleanfalse\floatp@sw}
+\DeclareOption{endfloats*}{\@booleanfalse\floats@sw\@booleantrue\floatp@sw}
+\@booleantrue\floats@sw
+\@booleantrue\floatp@sw
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{titlepage/notitlepage}%
+% These options control, via \cmd\titlepage@sw, 
+% whether the title block is to be set on a separate page.
+%
+% \begin{macro}{\titlepage@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The flag \cmd\titlepage@sw\ signifies that a forced 
+% page break is to follow the title page: the article
+% title appears on a page by itself.
+%
+%    \begin{macrocode}
+\DeclareOption{titlepage}{\@booleantrue\titlepage@sw}
+\DeclareOption{notitlepage}{\@booleanfalse\titlepage@sw}
+\@booleanfalse\titlepage@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Substyle and Sub-substyle}%
+%
+% \begin{macro}{\change@society}
+% \begin{macro}{\change@journal}
+% \changes{4.1b}{2008/07/01}{(AO) Provide more diagnostics when \cs{@society} is assigned.}
+% If the society or, resp., journal has already been assigned,
+% notify user whether it is being overridden. 
+% 
+%    \begin{macrocode}
+\def\change@society#1{%
+ \def\@tempa{#1}%
+ \@ifxundefined\@society{%
+  \class@info{Selecting society \@tempa}%
+  \let\@society\@tempa
+ }{%
+  \@ifx{\@tempa\@society}{}{%
+   \class@warn{Conflicting society \@tempa<>\@society; not selected}%
+  }%
+ }%
+}%
+\def\change@journal#1{%
+ \def\@tempa{#1}%
+ \@ifxundefined\@journal{%
+  \class@info{Selecting journal \@tempa}%
+  \let\@journal\@tempa
+ }{%
+  \@ifx{\@tempa\@journal}{}{%
+   \class@warn{Conflicting journal \@tempa<>\@journal; not selected}%
+  }%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% Here had been the class options relating to the APS.
+% Now that all societies are on an equal footing, this code is in the
+% respective \file{.rtx} file.
+%    \begin{macrocode}
+%    \end{macrocode}
+%
+% \subsubsection{Optical Society of America}%
+% Here are the class options relating to the Optical Society of America.
+%
+% Note: as of 2008, the only OSA module being distributed by ctan is \file{osajnl.rtx}.
+% The class options declared here are, I think, unused.
+%    \begin{macrocode}
+\DeclareOption{osa}{\change@society{osa}\let\@journal\@undefined}%
+\DeclareOption{osameet}{\change@society{osa}\def\@journal{osameet}}%
+\DeclareOption{opex}{\change@society{osa}\def\@journal{opex}}%
+\DeclareOption{tops}{\change@society{osa}\def\@journal{tops}}%
+\DeclareOption{josa}{\change@society{osa}\def\@journal{josa}}%
+%    \end{macrocode}
+%
+% \begin{macro}{\rtx@require@packages}
+% \changes{4.1b}{2008/07/01}{Read in all required packages together}
+% The procedure \cmd\rtx@require@packages\ accumulates all \cmd\RequirePackage\ statements
+% in the course of loading the document class. 
+% Carrying out these operations at that time is needed:
+% \cmd\ProcessOptions\ must be executed first. 
+%    \begin{macrocode}
+\let\rtx@require@packages\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\MakeUppercase}
+% \begin{macro}{\MakeLowercase}
+% \changes{4.1b}{2008/07/01}{Package textcase is now simply a required package}
+% \changes{4.1b}{2008/07/01}{Read in all required packages together}
+% \changes{4.1g}{2009/10/07}{(AO, 538) \cs{MakeTextUppercase} inappropriately expands the double backslash}
+% We load the \classname{textcase} package of David Carlisle.
+% Now that its bug of long standing has been repaired, we no longer need to doctor it up. 
+% And, because its loading has been deferred until \cmd\rtx@require@packages\ time, 
+% we no longer override \LaTeX\ here. Instead, the \classname{textcase} package
+% will be asked to do that. 
+%    \begin{macrocode}
+\appdef\rtx@require@packages{%
+ \RequirePackage[overload]{textcase}%
+}%
+%    \end{macrocode}
+% The following code used to
+% let the \classname{textcase} commands override those of \LaTeX:
+%    \begin{verbatim}
+%\appdef\setup@hook{%
+% \expandafter
+% \let\csname MakeUppercase \expandafter\endcsname
+%    \csname MakeTextUppercase \endcsname
+% \expandafter
+% \let\csname MakeLowercase \expandafter\endcsname
+%    \csname MakeTextLowercase \endcsname
+% }%
+%    \end{verbatim}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{amsfonts}
+% \changes{4.1b}{2008/07/01}{Read in all required packages together}
+% The class option \classoption{amsfonts} has the
+% same effect as if the document preamble contained
+% a \cmd\usepackage\verb${amsfonts}$ statement.
+%    \begin{macrocode}
+\DeclareOption{amsfonts}{%
+  \def\class@amsfonts{\RequirePackage{amsfonts}}%
+}%
+\DeclareOption{noamsfonts}{%
+  \let\class@amsfonts\@empty
+}%
+\appdef\rtx@require@packages{%
+ \@ifxundefined\class@amsfonts{}{\class@amsfonts}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{amssymb}
+% \changes{4.1b}{2008/07/01}{Read in all required packages together}
+% The class option \classoption{amssymb} has the
+% same effect as if the document preamble contained
+% a \cmd\usepackage\verb${amssymb}$ statement.
+%    \begin{macrocode}
+\DeclareOption{amssymb}{%
+  \def\class@amssymb{\RequirePackage{amssymb}}%
+}%
+\DeclareOption{noamssymb}{%
+  \let\class@amssymb\@empty
+}%
+\appdef\rtx@require@packages{%
+ \@ifxundefined\class@amssymb{}{\class@amssymb}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{amsmath}
+% \changes{4.1b}{2008/07/01}{Read in all required packages together}
+% The class option \classoption{amsmath} has the
+% same effect as if the document preamble contained
+% a \cmd\usepackage\verb${amsmath}$ statement.
+%
+% We require version 1.2 (datestamped 1997/03/20) or later.
+% The \expandafter\cmd\csname ver@amsmath.sty\endcsname, will 
+% 
+% \LaTeX\ note:
+% Certain \LaTeX\ procedures have an arbitrary and pointless restriction that they may be used only within the preamble.
+% We get around this by preserving the procedures in private \cmd\csname s.
+%
+% FIXME note: it is difficult to ensure that an error summary will be printed on the console at the very end,
+% but \classname{ltxgrid} allows accomplishing this via an interrupt, put down at \cmd\AtEndDocument\ time.
+%
+%    \begin{macrocode}
+\DeclareOption{amsmath}{%
+  \def\class@amsmath{\RequirePackage{amsmath}[\ver@amsmath@prefer]}%
+}%
+\DeclareOption{noamsmath}{%
+  \let\class@amsmath\@empty
+}%
+\appdef\rtx@require@packages{%
+ \preserve@LaTeX
+ \@ifxundefined\class@amsmath{}{\class@amsmath}%
+ \appdef\class@enddocumenthook{\test@amsmath@ver}%
+}%
+\appdef\preserve@LaTeX{%
+ \let\@ifl@aded@LaTeX\@ifl@aded
+ \let\@ifpackageloaded@LaTeX\@ifpackageloaded
+ \let\@pkgextension@LaTeX\@pkgextension
+ \let\@ifpackagelater@LaTeX\@ifpackagelater
+ \let\@ifl@ter@LaTeX\@ifl@ter
+ \let\@ifl@t@r@LaTeX\@ifl@t@r
+ \let\@parse@version@LaTeX\@parse@version
+}%
+\appdef\restore@LaTeX{%
+ \let\@ifl@aded\@ifl@aded@LaTeX
+ \let\@ifpackageloaded\@ifpackageloaded@LaTeX
+ \let\@pkgextension\@pkgextension@LaTeX
+ \let\@ifpackagelater\@ifpackagelater@LaTeX
+ \let\@ifl@ter\@ifl@ter@LaTeX
+ \let\@ifl@t@r\@ifl@t@r@LaTeX
+ \let\@parse@version\@parse@version@LaTeX
+}%
+\def\test@amsmath@ver{%
+ \begingroup
+  \restore@LaTeX
+  \@ifpackageloaded{amsmath}{%
+   \@ifpackagelater{amsmath}{\ver@amsmath@prefer}{}{%
+     \class@warn{%
+      You have loaded amsmath, version "\csname ver@amsmath.sty\endcsname",\MessageBreak
+      but this class requires version "\ver@amsmath@prefer", or later.\MessageBreak
+      Please update your LaTeX installation.
+     }%
+   }%
+  }{%
+  }%
+ \endgroup
+}%
+\def\ver@amsmath@prefer{2000/01/15 v2.05 AMS math features}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Presenting Authors and Their Affiliations}%
+% \changes{4.1b}{2008/07/01}{Code relating to new syntax for frontmatter has been placed in \file{ltxfront.dtx}}
+% Class options for presenting authors and their affiliations are now defined in 
+% \file{ltxfront.dtx}.
+%
+%    \begin{macrocode}
+%    \end{macrocode}
+%
+% \subsubsection{Typeset by \revtex}%
+%
+% \begin{macro}{\byrevtex@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% The flag \cmd\byrevtex@sw\ signifies that the document should
+% bear an imprint to the effect that it was formatted by this document class.
+%
+% The class option \classoption{byrevtex} signifies that you want the 
+% ``Typeset by \revtex'' byline to appear on your formatted output.
+% By default, no such byline appears.
+%    \begin{macrocode}
+\DeclareOption{byrevtex}{\@booleantrue\byrevtex@sw}%
+\@booleanfalse\byrevtex@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Attempt to fix float placement failure}%
+% 
+% \begin{macro}{\force@deferlist@sw}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% \revtex\ uses the \classname{ltxgrid} package, which provides the ability to attempt repairs when 
+% \LaTeX's float placement mechanism is about to fail, but that facility is turned off by default.
+% Users should invoke the \classoption{floatfix} document class option to enable this \LaTeX\ extension.
+% If not, a helpful message is printed in the log, indicating how to work around the difficulty.
+%    \begin{macrocode}
+\DeclareOption{floatfix}{\@booleantrue\force@deferlist@sw}%
+\DeclareOption{nofloatfix}{\@booleanfalse\force@deferlist@sw}%
+\@booleanfalse\force@deferlist@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@fltovf}
+% \begin{macro}{\@fltstk}
+%  The \LaTeX\ kernel error message \cmd\@fltovf\ may now be a bit more helpful to the user;
+%  likewise for the \cmd\@fltstk\ message of \classname{ltxgrid}.
+%    \begin{macrocode}
+\gdef\@fltovf{%
+ \@latex@error{%
+  Too many unprocessed floats%
+  \force@deferlist@sw{}{; try class option [floatfix]}%
+ }\@ehb
+}%
+\def\@fltstk{%
+ \@latex@warning{%
+  A float is stuck (cannot be placed)%
+  \force@deferlist@sw{}{; try class option [floatfix]}%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\ltxgrid@info@sw}
+% \begin{macro}{\outputdebug@sw}
+% The two options \classoption{ltxgridinfo} and \classoption{outputdebug} turn on informative diagnostics within the 
+% package \classname{ltxgrid}. Only people who really want to see this output will select these class options.
+% Consult documentation for the \classname{ltxgrid} package to see what output the related switches enable.
+%    \begin{macrocode}
+\DeclareOption{ltxgridinfo}{%
+ \@booleantrue\ltxgrid@info@sw
+%\@booleantrue\ltxgrid@foot@info@sw
+}%
+\DeclareOption{outputdebug}{%
+ \@booleantrue\outputdebug@sw
+ \@booleantrue\ltxgrid@info@sw
+ \@booleantrue\ltxgrid@foot@info@sw
+ \traceoutput
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Option to relax page height}%
+% 
+% \begin{macro}{\textheight@sw}
+% The \classname{ltxgrid} package can set text pages to their natural height or force them to the full 
+% text height; the latter is the default.
+% If setting the pages with a variable length,
+% the running foot will move up or down with the natural length of the text column.
+% While I recommend against doing so, this option will turn that switch to the latter setting.
+%    \begin{macrocode}
+\DeclareOption{raggedfooter}{\@booleanfalse\textheight@sw}%
+\DeclareOption{noraggedfooter}{\@booleantrue\textheight@sw}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Selecting procedure for processing abstract}%
+% \changes{4.1b}{2008/07/01}{Remove options newabstract and oldabstract}
+% Code defining options \classoption{newabstract} and \classoption{oldabstract} has been removed.
+%
+% \subsection{Option to turn on diagnostics in the frontmatter}%
+% 
+% \begin{macro}{\frontmatterverbose@sw}
+% \changes{4.1b}{2008/07/01}{Code relating to new syntax for frontmatter has been placed in \file{ltxfront.dtx}}
+% A diagnostic option, not for the average enduser, which reveals 
+% the workings of the frontmatter.
+% This code interfaces to that of \file{ltxfront.dtx}.
+%    \begin{macrocode}
+\DeclareOption{frontmatterverbose}{\@booleantrue\frontmatterverbose@sw}%
+\@booleanfalse\frontmatterverbose@sw
+%    \end{macrocode}
+% \end{macro}
+% 
+% \begin{macro}{\linenumbers@sw}
+% \changes{4.1f}{2009/07/07}{(AO, 513) Add class option linenumbers: number the lines a la \classname{lineno}}
+% \changes{4.1n}{2009/12/13}{(AO, 573) arrange to load \classname{lineno} after any other packages.}%
+% An option to number the lines of type in the output in the manner of \classname{lineno}.
+%
+% At present, we use that very package to implement this functionality.
+% This means that users may modify the workings of that package per its documentation (which see).
+%
+% However, compatibility with \classname{amsmath} requires that \classname{lineno} be loaded afterwards.
+% Therefore, we defer loading of this package until after the preamble is completed. 
+%    \begin{macrocode}
+\DeclareOption{linenumbers}{%
+ \appdef
+ \class@documenthook{%
+  \RequirePackage{lineno}[2005/11/02 v4.41]%
+  \linenumbersep4pt\relax
+  \linenumbers\relax
+ }%
+}%
+%    \end{macrocode}
+% By default, line numbering is off. 
+% \end{macro}
+% 
+% \begin{macro}{\NAT@merge}
+% \changes{4.1f}{2009/07/15}{(AO, 523) Add class option nomerge, to turn off new natbib 8.3 syntax}
+% Add class option nomerge, to turn off natbib 8.3 syntax for citation key. 
+% The default value of REVTeX 4.1 for \cmd\NAT@merge is \cmd\thr@@, which turns on  
+% the new syntax along with its semantics. 
+% Legacy documents that would be incompatible with the new syntax can be successfully processed 
+% with class option \classoption{nomerge}.
+%    \begin{macrocode}
+\DeclareOption{nomerge}{%
+ \appdef\setup@hook{%
+  \@ifnum{\NAT@merge>\z@}{\let\NAT@merge\z@}{}%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Default Option, Society, Journal, and pointsize}%
+%
+% \changes{4.1a}{2008/01/18}{(AO, 488) Change processing of options to allow an unused option to specify society and journal}%
+% This change will not break OSA documents because that society is still built in to revtex4.
+%
+% \begin{macro}{\@parse@class@options@society}
+% \begin{macro}{\@parse@class@options@}
+% \changes{4.1b}{2008/07/01}{Procedures \cs{@parse@class@options@society} and \cs{@parse@class@options@journal} and friends}
+% The procedure \cmd\@parse@class@options@society\ parses the options passed to this document class 
+% for the \cmd\@society. 
+% It is like \cmd\ProcessOptions*\ in that it accesses
+% \cmd\@ptionlist\{\cmd\@currname.\cmd\@currext\}.
+% Any undefined option is considered: if there is a corresponding \file{.rtx} file,
+% it will change the society accordingly
+% and define a placeholder class option for the society thus found
+% (thus preventing a spurious "option not found" message). 
+% 
+% The procedure \cmd\@parse@class@options@\ parses the document's options
+% for any that set the \cmd\csname\ provided. 
+%    \begin{macrocode}
+\def\@parse@class@options@society{%
+ \edef\@tempa{\@ptionlist{\@currname.\@currext}}%
+ \expandafter\@for\expandafter\CurrentOption\expandafter:\expandafter=\@tempa\do{%
+  \expandafter\@ifnotrelax\csname ds@\CurrentOption\endcsname{}{%
+   \IfFileExists{\CurrentOption\substyle@post.\substyle@ext}{%
+    \expandafter\change@society\expandafter{\CurrentOption}%
+    \expandafter\let\csname ds@\CurrentOption\endcsname\@empty
+   }{}%
+  }%
+ }%
+}%
+\def\@parse@class@options@#1{%
+ \edef\@tempa{\@ptionlist{\@currname.\@currext}}%
+ \expandafter\@for\expandafter\CurrentOption\expandafter:\expandafter=\@tempa\do{%
+  \expandafter\@ifnotrelax\csname ds@\CurrentOption\endcsname{%
+   \begingroup\csname ds@\CurrentOption\endcsname
+    \@ifxundefined#1{%
+     \endgroup
+    }{%
+     \expandafter\endgroup\expandafter\def\expandafter#1\expandafter{#1}%
+    }%
+  }{}%
+ }%
+}%
+\def\@parse@class@options@journal{%
+ \edef\@tempa{\@ptionlist{\@currname.\@currext}}%
+ \expandafter\@for\expandafter\CurrentOption\expandafter:\expandafter=\@tempa\do{%
+  \expandafter\@ifnotrelax\csname ds@\CurrentOption\endcsname{%
+   \begingroup
+    \csname ds@\CurrentOption\endcsname
+    \@ifxundefined\@journal{%
+     \endgroup
+    }{%
+     \expandafter\endgroup\expandafter\def\expandafter\@journal\expandafter{\@journal}%
+    }%
+  }{}%
+ }%
+}%
+\def\@parse@class@options{%
+ \edef\@tempa{\@ptionlist{\@currname.\@currext}}%
+ \expandafter\@for\expandafter\CurrentOption\expandafter:\expandafter=\@tempa\do{%
+  \expandafter\@ifnotrelax\csname ds@\CurrentOption\endcsname{%
+   \begingroup
+    \csname ds@\CurrentOption\endcsname
+    \@ifxundefined\@pointsize{%
+     \endgroup
+    }{%
+     \expandafter\endgroup\expandafter\def\expandafter\@pointsize\expandafter{\@pointsize}%
+    }%
+  }{%
+   \IfFileExists{\CurrentOption\substyle@post.\substyle@ext}{%
+    \expandafter\change@society\expandafter{\CurrentOption}%
+    \expandafter\let\csname ds@\CurrentOption\endcsname\@empty
+   }{}%
+  }%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \changes{4.1j}{2009/10/25}{(AO, 545) hypertext capabilities off by default; enable with \classoption{hypertext}}
+% The class option \classoption{hypertext} enables the built-in hypertext capabilities,
+% which coincide with those of \classname{custom-bib}-generated BIBTeX styles
+% using the guard code \texttt{hypertext}. 
+%
+% Note that APS has these capabilities turned off by default;
+% Loading the hyperref package turns them on.
+%    \begin{macrocode}
+\DeclareOption{hypertext}{\hypertext@enable@ltx}%
+\appdef\document@inithook{\@ifpackageloaded{hyperref}{\hypertext@enable@ltx}{}}%
+%    \end{macrocode}
+%
+% The default handling for a document class option depends upon whether the \cmd\@society\ is 
+% defined. 
+%
+% If not, then hunt for a \file{.rtx} file with that name.
+% If it exists, then we will take this option as the name of the society, 
+% otherwise, declare the option as not used.
+% 
+% (This behavior is similar to the \LaTeX2.09 handling, where
+% one looked for a \file{.sty} file, except that 
+% in this case, we must provide for journal substyles that may be 
+% defined in the society file, or have their own journal substyle file.)
+%
+% At the point where the class file is finished loading, 
+% we then read in the society file. 
+% That file can define further class options, such as the journal substyle.
+%
+% For users, this will mean that they can specify the society and journal simply 
+% by specifying first the former and then the latter among their document class options.
+% The society \emph{must} have a corresponding \file{.rtx}.
+%
+% \changes{4.1b}{2008/05/29}{The csname substyle@ext is now defined without a dot (.), to be compatible with \LaTeX usage (see @clsextension and @pkgextension).}
+%
+%    \begin{macrocode}
+%</options>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%<*package>
+%    \end{macrocode}
+%
+% \begin{macro}{\@process@society}
+% \begin{macro}{\@process@journal}
+% \begin{macro}{\@process@pointsize}
+%    \begin{macrocode}
+\def\substyle@post{4-2}%
+\def\substyle@ext{rtx}%
+\DeclareOption*{\OptionNotUsed}%
+%    \end{macrocode}
+% A society substyle may define its own options, via \cmd\DeclareOption. 
+%
+% At the end of this document class, we process the society file,
+% using \file{aps.rtx} if none has been specified in the document.
+%    \begin{macrocode}
+\def\@process@society#1{%
+ \@ifxundefined\@society{%
+  \class@warn{No Society specified, using default society #1}%
+  \def\@society{#1}\let\@journal\@undefined
+ }{}%
+ \expandafter\input\expandafter{\@society\substyle@post.\substyle@ext}%
+}%
+%    \end{macrocode}
+%
+% A society substyle can encompass any number of journal substyles;
+% we use the following procedure to invoke the proper one.
+%    \begin{macrocode}
+\def\@process@journal#1{%
+ \@ifxundefined\@journal{%
+  \class@warn{No journal specified, using default #1}%
+  \def\@journal{#1}%
+ }{}%
+ \expandafter\expandafter
+ \expandafter\rtx@do@substyle
+ \expandafter\expandafter
+ \expandafter{\expandafter\@society\@journal}%
+}%
+\def\rtx@do@substyle#1{%
+ \InputIfFileExists{#1\substyle@post.\substyle@ext}{}{\csname rtx@#1\endcsname}%
+}%
+%    \end{macrocode}
+% 
+% Document class options \classoption{10pt}, \classoption{11pt}, and \classoption{12pt} 
+% are implemented by \revtex\ itself and determine \cmd\@pointsize. 
+% These provide formatting settings appropriate to the society's journals. 
+%
+% If not specified by the document, a value \cmd\@pointsize@default\ is used. 
+% This default can be set by the journal. Here, the society sets its default. 
+%    \begin{macrocode}
+\def\@process@pointsize#1{%
+ \@ifxundefined\@pointsize{%
+  \def\@pointsize{#1}%
+  \class@warn{No type size specified, using default \@pointsize}%
+ }{}%
+ \expandafter\expandafter
+ \expandafter\rtx@do@substyle
+ \expandafter\expandafter
+ \expandafter{\expandafter\@society\@pointsize pt}%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Class-Asserted Options}%
+% \changes{4.0b}{1999/06/20}{Removed invocation of nonexistent class option \protect\classoption{groupauthors} and all other class options that should only be invoked by the document. (Otherwise precedence of class options does not work.)}
+% Here we establish the default document class options.
+% Those of the document itself will override these.
+%
+% \section{Procedures Dependent Upon Options}
+%
+% Here we introduce \classname{classes.dtx} definitions for 
+% the page styles that people will expect to be able to use.
+% \begin{macro}{\ps@headings}
+% \begin{macro}{\ps@myheadings}
+%    \begin{macrocode}
+  \def\ps@headings{%
+      \let\@oddfoot\@empty\let\@evenfoot\@empty
+      \def\@evenhead{\thepage\hfil\slshape\leftmark}%
+      \def\@oddhead{{\slshape\rightmark}\hfil\thepage}%
+      \let\@mkboth\markboth
+    \def\sectionmark##1{%
+      \markboth {\MakeUppercase{%
+        \ifnum \c@secnumdepth >\z@
+          \thesection\quad
+        \fi
+        ##1}}{}}%
+    \def\subsectionmark##1{%
+      \markright {%
+        \ifnum \c@secnumdepth >\@ne
+          \thesubsection\quad
+        \fi
+        ##1}}}%
+\def\ps@myheadings{%
+    \let\@oddfoot\@empty\let\@evenfoot\@empty
+    \def\@evenhead{\thepage\hfil\slshape\leftmark}%
+    \def\@oddhead{{\slshape\rightmark}\hfil\thepage}%
+    \let\@mkboth\@gobbletwo
+    \let\sectionmark\@gobble
+    \let\subsectionmark\@gobble
+    }%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\ps@article}
+% \begin{macro}{\ps@article@final}
+% \begin{macro}{\ps@preprint}
+% \changes{4.0a}{1998/01/31}{Move after process options, so the following test works}
+% \changes{4.0b}{1999/06/20}{Defer decision until \cs{AtBeginDocument} time}
+% \changes{4.0c}{1999/11/13}{Insert procedure \cs{checkindate}}
+% \changes{4.0rc1}{2001/06/17}{Running headers always as if two-sided}
+%    \begin{macrocode}
+\def\ps@article{%
+    \def\@evenhead{\let\\\heading@cr\thepage\quad\checkindate\hfil{\leftmark}}%
+    \def\@oddhead{\let\\\heading@cr{\rightmark}\hfil\checkindate\quad\thepage}%
+    \def\@oddfoot{}%
+    \def\@evenfoot{}%
+    \let\@mkboth\markboth
+  \let\sectionmark\@gobble
+  \let\subsectionmark\@gobble
+}%
+\def\ps@article@final{%
+    \def\@evenhead{\let\\\heading@cr\thepage\quad\checkindate\hfil{\leftmark}}%
+    \def\@oddhead{\let\\\heading@cr{\rightmark}\hfil\checkindate\quad\thepage}%
+    \def\@oddfoot{}%
+    \def\@evenfoot{}%
+    \let\@mkboth\markboth
+    \def\sectionmark##1{%
+      \markboth{%
+       \MakeTextUppercase{%
+        \@ifnum{\c@secnumdepth >\z@}{\thesection\hskip 1em\relax}{}%
+         ##1%
+       }%
+       }{}%
+    }%
+    \def\subsectionmark##1{%
+      \markright {%
+        \@ifnum{\c@secnumdepth >\@ne}{\thesubsection\hskip 1em\relax}{}%
+         ##1%
+      }%
+    }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\heading@cr{\unskip\space\ignorespaces}%
+%    \end{macrocode}
+%
+% \changes{4.0c}{1999/11/13}{Do not put by REVTeX in every page foot}
+% \changes{4.0c}{1999/11/13}{Insert procedure \cs{checkindate}}
+%    \begin{macrocode}
+\def\ps@preprint{%
+  \def\@oddfoot{\hfil\thepage\quad\checkindate\hfil}%
+  \def\@evenfoot{\hfil\thepage\quad\checkindate\hfil}%
+  \def\@oddhead{}%
+  \def\@evenhead{}%
+  \let\@mkboth\@gobbletwo
+  \let\sectionmark\@gobble
+  \let\subsectionmark\@gobble
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\let\@oddhead\@empty
+\let\@evenhead\@empty
+\let\@oddfoot\@empty
+\let\@evenfoot\@empty
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\lastpage@putlabel}
+% Support the default meaning of \cmd\@endpage.
+% \changes{4.0a}{1998/01/31}{Move after process options, so \cs{clearpage} not in scope of twocolumn}
+% \changes{4.1k}{2009/11/06}{(AO, 554) give the \cs{newlabel} command syntax appropriate to the hyperref package}
+% Name of this macro (and the \cmd\label\ key) taken from 
+% \url{CTAN:/macros/latex/contrib/other/lastpage}%
+% with code optimised slightly.
+%    \begin{macrocode}
+\def\lastpage@putlabel{%
+ \if@filesw
+  \begingroup
+    \advance\c@page\m@ne
+    \immediate\write\@auxout{\string\newlabel{LastPage}{{}{\thepage}{}{}{}}}%
+  \endgroup
+ \fi
+}%
+%    \end{macrocode}
+% Install a procedure into document endgame processing that 
+% labels the last page of the document.
+% This is done just before the \file{.aux} file
+% is closed, and does not require a \cmd\shipout, because it writes
+% directly to the \file{.aux} file.
+% Note that we assume no further \cmd\shipout s will be done past this point.
+% \changes{4.1n}{2009/12/09}{(AO, 569) execute the after-last-shipout procedures from within the safety of the output routine}%
+%    \begin{macrocode}
+\appdef\clear@document{%
+ \do@output@cclv{%
+  \lastpage@putlabel
+  \tally@box@size@sw{\total@text}{}%
+ }%
+}%
+\providecommand\write@column@totals{}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{Required Packages}
+% \url{CTAN:macros/latex/contrib/other/misc/url.sty}%
+%    \begin{macrocode}
+\appdef\rtx@require@packages{%
+ \RequirePackage{url}%
+}%
+%    \end{macrocode}
+%
+% \section{Incompatible Packages}
+%
+% We wait until after the preamble is processed, then check for any packages 
+% that might have been loaded which we know to be incompatible with \revtex.
+%
+% The \classname{multicol} package is incompatible with \classname{ltxgrid}, which replaces it.
+% The \classname{cite} package is incompatible with \classname{natbib}, which replaces its functionality.
+% The functionality of the \classname{mcite} package is provided by \classname{natbib}. 
+%    \begin{macrocode}
+\appdef\document@inithook{%
+ \incompatible@package{cite}%
+ \incompatible@package{mcite}%
+ \incompatible@package{multicol}%
+}%
+%    \end{macrocode}
+%
+% \section{Society- and Journal-Specific Code}
+%
+% \begin{macro}{\@journal}
+% Journal test helper, used as
+% \begin{verbatim}
+%\@ifx{\@journal\journal@pra}{%
+%  <journal-specific setup>
+%\fi
+% \end{verbatim}
+% Journal code might like to further specify (if as yet undefined) or distinguish on
+% the following Booleans.
+%
+% Note: the journal substyle code should only alter the value of one of these Booleans if
+% the Boolean is \cmd\undefined. This convention is what makes the document's
+% options take precedence over the values set by the journal.
+% 
+% FIXME: make this table an exhaustive listing of all the parameters set by
+% the class options.
+%
+% \begin{tabular}{ll}
+% \cmd\@pointsize      &(10|11|12), depending on the type size\\
+% \cmd\footinbib@sw    &true if footnotes are to be formatted in the bibliography\\
+% \cmd\preprintsty@sw  &true for preprint and hyperpreprint\\
+% \cmd\eqsecnum@sw     &true means that equations are numbered within sections\\
+% \cmd\groupauthors@sw &true means authors listed separately for each address\\
+% \cmd\preprint@sw     &true means to produce the preprint numbers as part of the title block\\
+% \cmd\showPACS@sw     &true means to produce the PACS as part of the title block\\
+% \cmd\showKEYS@sw     &true means to produce the keywords as part of the title block\\
+% \cmd\@affils@sw      &true means each affiliation is printed, for each author\\
+% \cmd\runinaddress@sw &true means author addresses are printed run-in\\
+% \cmd\draft@sw        &true implies that PACS will be printed\\
+% \cmd\tightenlines@sw &true if preprint single spaced\\
+% \cmd\lengthcheck@sw  &true if length checking is in effect\\
+% \cmd\byrevtex@sw     &true means to announce ``typeset by \revtex''\\
+% \cmd\titlepage@sw    &true for title is to be set on a separate page\\
+% \cmd\twocolumn@sw    &true if two-column page grid\\
+% \cmd\twocolumn@sw    &true if we are to automatically balance the columns of the last page\\
+% \cmd\twoside@sw      &true means to format pages for duplex printing\\
+% \cmd\floats@sw       &false means floats are migrated to end of document\\
+% \cmd\floatp@sw       &true means endfloats are set one to a page\\
+% \cmd\class@amsfonts  &if \cmd\@empty, means that \classname{amsfonts} will \emph{not} be loaded\\
+% \cmd\class@amssymb   &if \cmd\@empty, means that \classname{amssymb} will \emph{not} be loaded\\
+% \cmd\frontmatter@footnote &if \cmd\undefined, means that the default (\cmd\footnote) will be used\\
+% \cmd\place@bibnumber &if \cmd\undefined, means that the default (inline) will be used\\
+% \end{tabular}
+%
+% Note: if \cmd\twocolumn@sw\ and \cmd\preprintsty@sw\ are both false,
+% then `galley' style is in effect. The \classoption{galley} option invokes
+% \classoption{onecolumn}, but does not affect the \cmd\preprintsty@sw.
+%
+% Note: \cmd\paperwidth\ and \cmd\paperheight\ are not integrated into this scheme,
+% and should be selected by the document alone.
+% \end{macro}
+%
+% \section{Body}
+%
+% \subsection{counters}
+% The following definitions are probably identical to those in 
+% \file{classes.dtx}%
+%    \begin{macrocode}
+\def\labelenumi{\theenumi.}
+\def\theenumi{\arabic{enumi}}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\labelenumii{(\theenumii)}
+\def\theenumii{\alph{enumii}}
+\def\p@enumii{\theenumi}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\labelenumiii{\theenumiii.}
+\def\theenumiii{\roman{enumiii}}
+\def\p@enumiii{\theenumi(\theenumii)}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\labelenumiv{\theenumiv.}
+\def\theenumiv{\Alph{enumiv}}
+\def\p@enumiv{\p@enumiii\theenumiii}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\labelitemi{\textbullet}
+\def\labelitemii{\normalfont\bfseries\textendash}
+\def\labelitemiii{\textasteriskcentered}
+\def\labelitemiv{\textperiodcentered}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\pagenumbering{arabic}
+%    \end{macrocode}
+%
+% \subsection{float parameters}
+%
+% from the old aps.sty. (DPC: same as article I think)
+% AO: here, \LaTeX's standard classes fail very poorly
+% (the price of backward compatability): the values for
+% \cmd\floatpagefraction\ and \cmd\dblfloatpagefraction\
+% need to be raised to avoid creating extremely short
+% float pages.
+%    \begin{macrocode}
+\setcounter{topnumber}{2}
+\def\topfraction{.9}
+\setcounter{bottomnumber}{1}
+\def\bottomfraction{.9}
+\setcounter{totalnumber}{3}
+\def\textfraction{.1}
+\def\floatpagefraction{.9}
+\setcounter{dbltopnumber}{2}
+\def\dbltopfraction{.9}
+\def\dblfloatpagefraction{.9}
+%    \end{macrocode}
+%
+% \subsection{List Environments}
+%
+%    \begin{macrocode}
+\newenvironment{verse}{%
+  \let\\=\@centercr
+  \list{}{%
+    \itemsep\z@ \itemindent -1.5em\listparindent \itemindent
+    \rightmargin\leftmargin\advance\leftmargin 1.5em}\item[]%
+}{%
+ \endlist
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newenvironment{quotation}{%
+  \list{}{%
+    \listparindent 1.5em
+    \itemindent\listparindent
+    \rightmargin\leftmargin \parsep \z@ \@plus\p@}\item[]%
+}{%
+ \endlist
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newenvironment{quote}{%
+  \list{}{%
+  \rightmargin\leftmargin}\item[]%
+}{%
+ \endlist
+}%
+%    \end{macrocode}
+%
+% \changes{4.1b}{2008/06/30}{(AO) Structure the Abstract using the \texttt{bibliography} environment}
+%    \begin{macrocode}
+\def\descriptionlabel#1{%
+  \hspace\labelsep \normalfont\bfseries #1\unskip:%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\newenvironment{description}{%
+ \list{}{%
+    \labelwidth\z@ \itemindent-\leftmargin
+    \let\makelabel\descriptionlabel
+ }%
+}{%
+ \endlist
+}%
+%    \end{macrocode}
+%
+% \subsection{Sectioning Commands\label{sec:secnumarabic}}
+%
+% \subsubsection{Sectioning Commands and Their Productions}%
+% The following counters are defined by LaTeX's standard document classes.
+% We do likewise, then assign flag values to the productions, awaiting
+% overrides.
+%    \begin{macrocode}
+\newcounter{part}%
+\let\thepart\@undefined
+\newcounter{section}%
+\let\thesection\@undefined
+\newcounter{subsection}[section]%
+\let\thesubsection\@undefined
+\newcounter{subsubsection}[subsection]%
+\let\thesubsubsection\@undefined
+\newcounter{paragraph}[subsubsection]%
+\let\theparagraph\@undefined
+\newcounter{subparagraph}[paragraph]%
+\let\thesubparagraph\@undefined
+%    \end{macrocode}
+% The procedure invoked by \cmd\setup@secnums\ provides meanings for these productions. 
+% 
+% \begin{macro}{\secnums@rtx}
+% \begin{macro}{\secnums@arabic}
+% These two procedures define the meanings of each of the productions
+% of the counters of the sectioning commands,
+% but only if nothing else has defined it.
+%    \begin{macrocode}
+\def\secnums@rtx{%
+ \@ifxundefined\thepart{%
+  \def\thepart{\Roman{part}}%
+ }{}%
+ \@ifxundefined\thesection{%
+  \def\thesection       {\Roman{section}}%
+  \def\p@section        {}%
+ }{}%
+ \@ifxundefined\thesubsection{%
+  \def\thesubsection    {\Alph{subsection}}%
+  \def\p@subsection     {\thesection\,}%
+ }{}%
+ \@ifxundefined\thesubsubsection{%
+  \def\thesubsubsection {\arabic{subsubsection}}%
+  \def\p@subsubsection  {\thesection\,\thesubsection\,}%
+ }{}%
+ \@ifxundefined\theparagraph{%
+  \def\theparagraph     {\alph{paragraph}}%
+  \def\p@paragraph      {\thesection\,\thesubsection\,\thesubsubsection\,}%
+ }{}%
+ \@ifxundefined\thesubparagraph{%
+  \def\thesubparagraph  {\arabic{subparagraph}}%
+  \def\p@subparagraph   {\thesection\,\thesubsection\,\thesubsubsection\,\theparagraph\,}%
+ }{}%
+}%
+\def\secnums@arabic{%
+ \@ifxundefined\thepart{%
+  \def\thepart          {\Roman{part}}%
+ }{}%
+ \@ifxundefined\thesection{%
+  \def\thesection       {\Roman{section}}%
+  \def\p@section        {}%
+ }{}%
+ \@ifxundefined\thesubsection{%
+  \def\thesubsection    {\thesection.\arabic{subsection}}%
+  \def\p@subsection     {}%
+ }{}%
+ \@ifxundefined\thesubsubsection{%
+  \def\thesubsubsection {\thesubsection.\arabic{subsubsection}}%
+  \def\p@subsubsection  {}%
+ }{}%
+ \@ifxundefined\theparagraph{%
+  \def\theparagraph     {\thesubsubsection.\arabic{paragraph}}%
+  \def\p@paragraph      {}%
+ }{}%
+ \@ifxundefined\thesubparagraph{%
+  \def\thesubparagraph  {\theparagraph.\arabic{subparagraph}}%
+  \def\p@subparagraph   {}%
+ }{}%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{The Acknowledgments Environment}%
+% This user-level markup produces a head introducing 
+% the acknowledgments, and acts as a wrapper for the text.
+% In this implementation, it is an unnumbered section,
+% but appears within the toc.
+%
+% For compatiability's sake, we implement it under the alternative
+% spelling \env{acknowledgements}.
+% \changes{4.0c}{1999/11/13}{also spelled ``acknowledgements''.}
+% \changes{4.0d}{2000/05/18}{But alternative spelling is deprecated.}
+%    \begin{macrocode}
+\newenvironment{acknowledgments}{%
+ \acknowledgments@sw{%
+  \expandafter\section\expandafter*\expandafter{\acknowledgmentsname}%
+ }{%
+  \par
+  \phantomsection
+  \addcontentsline{toc}{section}{\protect\numberline{}\acknowledgmentsname}%
+ }%
+}{%
+ \par
+}%
+\@booleantrue\acknowledgments@sw
+\newenvironment{acknowledgements}{%
+ \replace@environment{acknowledgements}{acknowledgments}%
+}{%
+ \endacknowledgments
+}%
+%    \end{macrocode}
+%
+% \subsubsection{Part Opener}%
+% section setup copied verbatim from revtex3 aps/osa.
+% Does not explicitly depend on pointsize options.
+%    \begin{macrocode}
+\def\part{\par
+   \addvspace{4ex}%
+   \@afterindentfalse
+   \secdef\@part\@spart}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@part[#1]#2{%
+ \@ifnum{\c@secnumdepth >\m@ne}{%
+        \refstepcounter{part}%
+        \addcontentsline{toc}{part}{\thepart\hspace{1em}#1}%
+ }{%
+      \addcontentsline{toc}{part}{#1}%
+ }%
+ \begingroup
+    \parindent \z@ \raggedright
+    \interlinepenalty\@M
+    \@ifnum{\c@secnumdepth >\m@ne}{%
+      \Large \bf \partname~\thepart%
+      \par\nobreak
+    }{}%
+    \huge \bf
+    #2%
+    \markboth{}{}\par
+ \endgroup
+   \nobreak
+   \vskip 3ex
+   \@afterheading
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@spart#1{{\parindent \z@ \raggedright
+    \interlinepenalty\@M
+    \huge \bf
+    #1\par}
+    \nobreak
+    \vskip 3ex
+    \@afterheading}
+%    \end{macrocode}
+%
+% \subsubsection{Stacked Heads}%
+% Here are the class default definitions for sectioning commands.
+% A society or a journal substyle will likely override these definitions.
+%
+% In doing so, you can customize the formatting for a particular level by defining,
+% e.g., \cmd\@hangfrom@section\ or \cmd\@subsectioncntformat.
+%    \begin{macrocode}
+\def\section{%
+  \@startsection
+    {section}%
+    {1}%
+    {\z@}%
+    {0.8cm \@plus1ex \@minus .2ex}%
+    {0.5cm}%
+    {\normalfont\small\bfseries}%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\subsection{%
+  \@startsection
+    {subsection}%
+    {2}%
+    {\z@}%
+    {.8cm \@plus1ex \@minus .2ex}%
+    {.5cm}%
+    {\normalfont\small\bfseries}%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\subsubsection{%
+  \@startsection
+    {subsubsection}%
+    {3}%
+    {\z@}%
+    {.8cm \@plus1ex \@minus .2ex}%
+    {.5cm}%
+    {\normalfont\small\itshape}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{Runin Heads}%
+%    \begin{macrocode}
+\def\paragraph{%
+  \@startsection
+    {paragraph}%
+    {4}%
+    {\parindent}%
+    {\z@}%
+    {-1em}%
+    {\normalfont\normalsize\itshape}%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\subparagraph{%
+  \@startsection
+    {subparagraph}%
+    {5}%
+    {\parindent}%
+    {3.25ex \@plus1ex \@minus .2ex}%
+    {-1em}%
+    {\normalfont\normalsize\bfseries}%
+}%
+%    \end{macrocode}
+%
+%
+% \subsection{Math}
+%
+% \begin{macro}{\theequation}
+% We change the production of the equation counter so that 
+% we can accomodate the \classoption{eqsecnum} option.
+%    \begin{macrocode}
+\def\theequation{%
+ \theequation@prefix\arabic{equation}%
+}%
+\def\theequation@prefix{}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Type Size-Dependent Settings}
+%
+% \subsection{All Point Sizes}
+%    \begin{macrocode}
+\setcounter{secnumdepth}{4}
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\lineskip 1pt
+\normallineskip 1pt
+\def\baselinestretch{1}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\@lowpenalty   51
+\@medpenalty  151
+\@highpenalty 301
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\@beginparpenalty -\@lowpenalty
+\@endparpenalty   -\@lowpenalty
+\@itempenalty     -\@lowpenalty
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\arraycolsep 3pt
+\tabcolsep 2pt
+\arrayrulewidth .4pt
+\doublerulesep 2pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\skip\@mpfootins = 0pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\fboxsep  = 3.0pt
+\fboxrule = 0.4pt
+%    \end{macrocode}
+%
+% \subsection{Figures}
+% \changes{4.0b}{1999/06/20}{Processing delayed to \cs{AtBeginDocument} time}
+%
+% \begin{environment}{figure}
+% We define the \env{figure} environment.
+% Later, we will horse around with its meaning
+% in order to accomodate \cmd\floats@sw.
+%    \begin{macrocode}
+\newenvironment{figure}
+               {\@float{figure}}
+               {\end@float}
+\newenvironment{figure*}
+               {\@dblfloat{figure}}
+               {\end@dblfloat}
+%    \end{macrocode}
+% \end{environment}
+%
+%    \begin{macrocode}
+\def\listoffigures{\print@toc{lof}}%
+\def\l@figure{\@dottedtocline{1}{1.5em}{2.3em}}%
+%    \end{macrocode}
+%
+% \begin{macro}{\@makecaption}
+% If caption is one line long, to be centered; if lines turn, then set justified.
+%    \begin{macrocode}
+\newlength\abovecaptionskip
+\newlength\belowcaptionskip
+\setlength\abovecaptionskip{10\p@}
+\setlength\belowcaptionskip{2\p@}
+%    \end{macrocode}
+%
+% \changes{4.0b}{1999/06/20}{One-line caption sets flush left.}
+% \changes{4.0c}{1999/11/13}{Prevent an inner footnote from performing twice}
+% \changes{4.1a}{2008/01/18}{(AO, 460) ``Proper style is "FIG. 1. ..." (no colon)''}%
+% There is a hook \cmd\@caption@fignum@sep\ for determining 
+% the separator following the float number, e.g., ``Fig.1''.
+% Formerly, we had defined it to be ``: '', now the colon has been replace by a period (full stop). 
+%    \begin{macrocode}
+\long\def\@makecaption#1#2{%
+  \par
+% \nobreak
+  \vskip\abovecaptionskip
+  \begingroup
+   \small\rmfamily
+   \sbox\@tempboxa{%
+    \let\\\heading@cr
+    \@make@capt@title{#1}{#2}%
+   }%
+   \@ifdim{\wd\@tempboxa >\hsize}{%
+    \begingroup
+     \samepage
+     \flushing
+     \let\footnote\@footnotemark@gobble
+     \@make@capt@title{#1}{#2}\par
+    \endgroup
+   }{%
+     \global \@minipagefalse
+     \hb@xt@\hsize{\hfil\unhbox\@tempboxa\hfil}%
+   }%
+  \endgroup
+  \vskip\belowcaptionskip
+}%
+\def\@make@capt@title#1#2{%
+ \@ifx@empty\float@link{\@firstofone}{\expandafter\href\expandafter{\float@link}}%
+  {#1}\@caption@fignum@sep#2%
+}%
+\def\@footnotemark@gobble{%
+ \@footnotemark
+ \@ifnextchar[{\@gobble@opt@i}{\@gobble}%
+}%
+\def\@gobble@opt@i[#1]#2{}%
+\def\@mpmakefntext#1{%
+ \flushing
+ \parindent=1em
+ \noindent
+ \hb@xt@1em{\hss\@makefnmark}%
+ #1%
+}%
+\def\@caption@fignum@sep{. }%
+\def\setfloatlink{\def\float@link}%
+\let\float@link\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\thefigure}
+% The figure counter and float placement defaults.
+%    \begin{macrocode}
+\newcounter{figure}
+\renewcommand \thefigure {\@arabic\c@figure}
+%    \end{macrocode}
+% Note that we give the `!' modifier by default.
+% This is an effort to avoid the syndrome wherein
+% a deferred float finds itself unqualified for 
+% placement, thereby getting carried until \cmd\clearpage.
+%    \begin{macrocode}
+\def\fps@figure{tbp}
+\def\ftype@figure{1}
+\def\ext@figure{lof}
+\def\fnum@figure{\figurename~\thefigure}
+%    \end{macrocode}
+% We allocate a box register for use in tallying the column inches of floats of this type.
+%    \begin{macrocode}
+\expandafter\newbox\csname fbox@\ftype@figure\endcsname
+\expandafter\setbox\csname fbox@\ftype@figure\endcsname\hbox{}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Deferring \env{figure} Floats}%
+%
+% We determine if figures are to float or be deferred until \cmd\printfigures\ time. 
+% If so, we open the stream that will receive the deferred document portions. 
+%    \begin{macrocode}
+\appdef\class@documenthook{%
+ \do@if@floats{figure}{.fgx}%
+}%
+\appdef\class@enddocumenthook{%
+ \printfigures\relax
+}%
+%    \end{macrocode}
+% 
+% \begin{macro}{\printfigures}
+% The user-level command \cmd\printfigures\ determines
+% where the figures are to appear in a document in which
+% \cmd\floats@sw\ is false.
+% If the user invokes the \classoption{endfloats} class option and fails to
+% insert a \cmd\printfigures\ command, 
+% the figures will be printed at the end of the document.
+% If the command is given, but floats are not being deferred, 
+% it amounts to a no-op.
+% \changes{4.0b}{1999/06/20}{call \cs{print@floats}}
+% \changes{4.0c}{1999/11/13}{*-form mandates pagebreak}
+%    \begin{macrocode}
+\newcommand\printfigures{%
+ \@ifstar{\true@sw}{\floatp@sw{\true@sw}{\false@sw}}%
+ {%
+  \print@float{figure}{\oneapage}%
+ }{%
+  \print@float{figure}{}%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \begin{macro}{\@xfloat@prep}
+% We patch into the procedure \cmd\@xfloat@prep. 
+% This patch applies to all floats (not \env{figure} alone)
+% and makes the type center.
+%    \begin{macrocode}
+\appdef\@xfloat@prep{%
+ \appdef\@parboxrestore{\centering}%
+%\let\@makefnmark\@makefnmark@latex
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Tables}
+% \changes{4.0b}{1999/06/20}{Processing delayed to \cs{AtBeginDocument} time}
+%
+% DPC: More or less taken from \file{revtex2} \file{aps.sty},
+% but using dcolumn for decimal alignment.
+% \begin{environment}{table}
+% We define the \env{table} environment.
+% Later, we will horse around with its meaning
+% in order to accomodate \cmd\floats@sw.
+%    \begin{macrocode}
+\newenvironment{table}
+               {\@float{table}}
+               {\end@float}
+\newenvironment{table*}
+               {\@dblfloat{table}}
+               {\end@dblfloat}
+%    \end{macrocode}
+% \end{environment}
+%
+% \begin{macro}{\thetable}
+% Table counter and default float placement declarations.
+%    \begin{macrocode}
+\newcounter{table}
+\renewcommand\thetable{\@Roman\c@table}
+%    \end{macrocode}
+% Note that we give the `!' modifier by default.
+% This is an effort to avoid the syndrome wherein
+% a deferred float finds itself unqualified for 
+% placement, thereby getting carried until \cmd\clearpage.
+%    \begin{macrocode}
+\def\fps@table{tbp}
+\def\ftype@table{2}
+\def\ext@table{lot}
+\def\fnum@table{\tablename~\thetable}
+%    \end{macrocode}
+% We allocate a box register for use in tallying the column inches of floats of this type.
+%    \begin{macrocode}
+\expandafter\newbox\csname fbox@\ftype@table\endcsname
+\expandafter\setbox\csname fbox@\ftype@table\endcsname\hbox{}%
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+\def\listoftables{\print@toc{lot}}%
+\let\l@table\l@figure
+%    \end{macrocode}
+%
+% \begin{macro}{\table@hook}
+% \begin{macro}{\squeezetable}
+% Assign a meaning to the hook installed into float processing.
+%
+% By default floats are \cmd\small. The \cmd\squeezetable\ declaration
+% makes them smaller (\cmd\scriptsize). In general you can locally
+% redefine \cmd\table@hook\ to be whatever you like.
+% (DPC: |\Huge\color{magenta}|\ldots?)
+%    \begin{macrocode}
+\def\table@hook{\small}%
+\def\squeezetable{\def\table@hook{\scriptsize}}%
+\appdef\@floatboxreset{\table@hook}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Deferring \env{table} Floats}%
+%
+% After all packages are loaded, we decide
+% if tables will float or will be deferred until \cmd\printtables\ time.
+%
+% We also deal with the possibility of \env{longtable} environments.
+% 
+%    \begin{macrocode}
+\def\set@table@environments{%
+ \floats@sw{}{%
+  \let@environment{longtable@float}{longtable}%
+  \let@environment{longtable}{longtable@write}%
+  \let@environment{longtable*@float}{longtable*}%
+  \let@environment{longtable*}{longtable*@write}%
+  \let@environment{turnpage@float}{turnpage}%
+  \let@environment{turnpage}{turnpage@write}%
+ }%
+ \do@if@floats{table}{.tbx}%
+}%
+\appdef\document@inithook{%
+ \set@table@environments
+}%
+\appdef\class@enddocumenthook{%
+ \printtables\relax
+}%
+\newenvironment{longtable@write}{%
+ \write@@float{longtable}{table}%
+}{%
+ \endwrite@float
+}%
+\newenvironment{longtable*@write}{%
+ \write@@float{longtable*}{table}%
+}{%
+ \endwrite@float
+}%
+\newenvironment{turnpage@write}{%
+ \immediate\write\tablewrite{\string\begin{turnpage}}%
+}{%
+ \immediate\write\tablewrite{\string\end{turnpage}}%
+}%
+%    \end{macrocode}
+%
+% \begin{macro}{\printtables}
+% The user-level command \cmd\printtables\ determines
+% where the tables are to appear in a document in which
+% \cmd\floats@sw\ is false.
+% If the user invokes the \classoption{nofloats} and fails to
+% insert a \cmd\printtables\ command, 
+% the tables will be printed at the end of the document.
+% If the command is given, but floats are not being deferred, 
+% it amounts to a no-op.
+% \changes{4.0b}{1999/06/20}{only execute if appropriate}
+% \changes{4.0c}{1999/11/13}{*-form mandates pagebreak}
+% \changes{4.0d}{2000/05/17}{make longtable trigger the head, too}
+%    \begin{macrocode}
+\newcommand\printtables{%
+ \begingroup
+  \let@environment{longtable}{longtable@float}%
+  \let@environment{longtable*}{longtable*@float}%
+  \let@environment{turnpage}{turnpage@anchored}%
+  \prepdef\longtable{\trigger@float@par}%
+  \expandafter\prepdef\csname longtable*\endcsname{\trigger@float@par}%
+  \expandafter\prepdef\csname table@floats\endcsname{%
+   \onecolumngrid@push
+  }%
+  \expandafter\appdef\csname endtable@floats\endcsname{%
+   \onecolumngrid@pop
+  }%
+  \@ifstar{\true@sw}{\floatp@sw{\true@sw}{\false@sw}}%
+  {%
+   \print@float{table}{\oneapage}%
+  }{%
+   \print@float{table}{}%
+  }%
+ \endgroup
+}%
+\newenvironment{turnpage@anchored}{%
+ \onecolumngrid@push
+ \setbox\z@\vbox to\textwidth\bgroup
+  \columnwidth\textheight
+}{%
+  \vfil
+ \egroup
+ \rotatebox{90}{\box\z@}%
+ \onecolumngrid@pop
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsection{Videos}
+%\changes{4.1r}{2010/06/22}{(AO, 595) Provide \cs{lovname} along with other List of Videos definitions.}%
+%
+% \begin{environment}{video}
+% We define the \env{video} environment analogously to the 
+% \env{figure} and \env{table} environments; it is intended to contain a video.
+%
+%    \begin{macrocode}
+\newenvironment{video}
+ {\@float{video}}
+ {\end@float}%
+\newenvironment{video*}
+ {\@dblfloat{video}}
+ {\end@dblfloat}%
+%    \end{macrocode}
+% \end{environment}
+%
+% \begin{macro}{\thevideo}
+% The video counter, float placement defaults, strings.
+%    \begin{macrocode}
+\newcounter{video}
+\renewcommand \thevideo {\@arabic\c@video}
+%    \end{macrocode}
+%
+% File extension and localizable strings.
+%    \begin{macrocode}
+\def\ext@video{lov}%
+\def\fname@video{Video}%
+\def\lovname{List of Videos}%
+%    \end{macrocode}
+%
+% Float type and default placement. 
+%    \begin{macrocode}
+\def\fps@video{tbp}%
+\def\ftype@video{4}%
+\def\fnum@video{\fname@video~\thevideo}%
+\appdef\document@inithook{%
+ \@ifxundefined\c@float@type{}{%
+  \global\setcounter{float@type}{8}%
+ }%
+}%
+%    \end{macrocode}
+% We allocate a box register for use in tallying the column inches of floats of this type.
+%    \begin{macrocode}
+\expandafter\newbox\csname fbox@\ftype@video\endcsname
+\expandafter\setbox\csname fbox@\ftype@video\endcsname\hbox{}%
+%    \end{macrocode}
+% The documentation for the \classname{hyperref} package, \file{hyperref.dtx} states:
+% ``classes or package which introduce new elements need to define 
+%   an equivalent  \verb+\theH<name>+  for every  \verb+\the<name>+''
+% We do accordingly here.
+%    \begin{macrocode}
+\let\theHvideo\thevideo
+%    \end{macrocode}
+% But \file{hyperref.dtx} goes on to say, 
+% ``We do make a trap to make \verb+\theH<name>+ be the same as \verb+\arabic{<name>}+,
+% if \verb+\theH<name>+ is not defined\ldots''
+% However, it's not doing that right now (as of 6.77u), 
+% and I cannot find any such code in there anymore.
+% \end{macro}
+%
+%    \begin{macrocode}
+\def\listofvideos{\print@toc{lov}}%
+\let\l@video\l@figure
+%    \end{macrocode}
+%
+% \subsubsection{Deferring \env{video} Floats}%
+%
+% We determine if videos are to float or be deferred until \cmd\printvideos\ time. 
+% If so, we open the stream that will receive the deferred document portions. 
+%    \begin{macrocode}
+\appdef\class@documenthook{%
+ \do@if@floats{video}{.vdx}%
+}%
+\appdef\class@enddocumenthook{%
+ \printvideos\relax
+}%
+%    \end{macrocode}
+% 
+% \begin{macro}{\printvideos}
+% The user-level command \cmd\printvideos\ determines
+% where the videos are to appear in a document in which
+% \cmd\floats@sw\ is false.
+% If the user invokes the \classoption{endfloats} class option and fails to
+% insert a \cmd\printvideos\ command, 
+% the videos will be printed at the end of the document.
+% If the command is given, but floats are not being deferred, 
+% it amounts to a no-op.
+%    \begin{macrocode}
+\newcommand\printvideos{%
+ \@ifstar{\true@sw}{\floatp@sw{\true@sw}{\false@sw}}%
+ {%
+  \print@float{video}{\oneapage}%
+ }{%
+  \print@float{video}{}%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \section{Tabular}
+% Every APS tabular has a double (Scotch) rule above and below.
+% The column specifier ``d'' is implemented using the \classname{dcolumn}
+% package, if available.
+% FIXME: always load dcolumn!
+% \begin{macro}{\tabular@hook}
+% \begin{macro}{\endtabular@hook}
+% \begin{environment}{ruledtabular}
+%    \begin{macrocode}
+\def\endtabular@hook{}%
+%    \end{macrocode}
+%    \begin{verbatim}
+%\RequirePackage{dcolumn}%
+%    \end{verbatim}
+%    \begin{macrocode}
+\appdef\document@inithook{%
+ \@ifpackageloaded{dcolumn}{%
+  \expandafter\@ifnotrelax\csname NC@find@d\endcsname{}{%
+   \newcolumntype{d}{D{.}{.}{-1}}%
+  }%
+ }{}%
+}%
+\def\toprule{\hline\hline}%
+\def\colrule{\hline}%
+\def\botrule{\hline\hline}%
+\newenvironment{ruledtabular}{%
+ \def\array@default{v}%
+ \appdef\tabular@hook{\def\@halignto{to\hsize}}%
+ \let\tableft@skip@default\tableft@skip
+ \let\tableft@skip\tableft@skip@float
+ \let\tabmid@skip@default\tabmid@skip
+ \let\tabmid@skip\tabmid@skip@float
+ \let\tabright@skip@default\tabright@skip
+ \let\tabright@skip\tabright@skip@float
+ \let\array@row@pre@default\array@row@pre
+ \let\array@row@pre\array@row@pre@float
+ \let\array@row@pst@default\array@row@pst
+ \let\array@row@pst\array@row@pst@float
+ \appdef\array@row@rst{%
+  \let\array@row@pre\array@row@pre@default
+  \let\array@row@pst\array@row@pst@default
+  \let\tableft@skip\tableft@skip@default
+  \let\tabmid@skip\tabmid@skip@default
+  \let\tabright@skip\tabright@skip@default
+  \appdef\tabular@hook{\let\@halignto\@empty}%
+ }%
+}{%
+}%
+%    \end{macrocode}
+% \end{environment}
+% \end{macro}
+% \end{macro}
+%
+% \section{Footnote Text}
+%
+% \changes{4.0a}{1998/06/10}{single space footnotes}
+% \changes{4.0b}{1999/06/20}{Frank Mittelbach, has stated in \protect\classname{multicol}: ``The kernel command \cs{@footnotetext} should not be modified.'' Thus, I have removed David Carlisle's redefinition of that command. Note, however, that later versions of \protect\classname{multicol} do not require this workaround. Belt and suspenders.}%
+%
+% \begin{macro}{\@makefntext}
+% \begin{macro}{\@makefnmark}
+% We customize the presentation of the footnote mark: it will not be italic.
+%    \begin{macrocode}
+\def\@makefntext#1{%
+  \def\baselinestretch{1}%
+  \parindent1em%
+  \noindent
+  \hb@xt@1.8em{%
+   \hss\@makefnmark
+  }%
+  #1%
+  \par
+}%
+\def\@makefnmark{%
+ \hbox{%
+  \@textsuperscript{%
+   \normalfont\@thefnmark
+  }%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsection{Citations, Bibliography, Endnotes}
+%
+% \subsubsection{Bibliography}
+%
+% Load Patrick Daly's \classname{natbib} package,
+% \url{ftp://ctan.tug.org/macros/latex/contrib/supported/natbib}
+%
+% Note that \classname{natbib} assumes that it loads
+% over a document class, such as the \classname{article} class, 
+% that has already defined \env{thebibliography} and \cmd\@listi.
+%
+% Note also that \classname{natbib} also installs a command
+% \cmd\NAT@set@cites\ into \cmd\AtBeginDocument\ which presumes
+% that the proper \cmd\bibpunct\ command has been issued.
+% 
+% Note that the macro \cmd\NAT@sort\ controls 
+% whether citations are left alone (\cmd\NAT@sort=0), sorted (\cmd\NAT@sort=1), or sorted and compressed (\cmd\NAT@sort=2).
+% Since we give \classname{natbib} the \classoption{sort\&compress} option,
+% if you prefer \classoption{sort}, you need only \cmd\let \cmd\NAT@sort\ to be \cmd\@ne.
+% However, if you prefer the effect of having neither \classoption{sort} nor \classoption{sort\&compress},
+% you must \cmd\let \cmd\NAT@sort\ to be \cmd\z@ and you must also define 
+% \cmd\let\cmd\NAT@cmprs\ to be \cmd\z@.
+%
+% As of version 8.2, \classname{natbib} now no longer binds at the point where it is read in.
+% This means that we can freely change \cmd\NAT@sort, \cmd\NAT@cmprs, and the new
+% \cmd\NAT@merge. Henceforth, we require that this later version be used.
+%
+% For other \classname{natbib} customizations, you may proceed as if you were going to use
+% the \file{natbib.cfg} file: anything that you can modify by this means is fair game.
+% Once \revtex\ is finished loading, you can assert any definitions for \classname{natbib} that you wish.
+%
+% \begin{macro}{\rev@citet}
+% \begin{macro}{\rev@citealp}
+% \begin{macro}{\rev@citealpnum}
+% We define variants on \classname{natbib}'s commands \cmd\citet, \cmd\citealp, and \cmd\citealpnum. 
+% \cmd\rev@citealpnum\ uses a numerical citation.
+% \cmd\rev@citealp\ and \cmd\rev@citealpnum\ are the aliases of \cmd\onlinecite,
+% \cmd\rev@citet\ that of \cmd\textcite.
+% 
+% In each case, we invoke \cmd\rtx@swap@citea\ to effect different productions between 
+% multiple arguments to the \cmd\cite\ command.
+%
+% \cmd\rev@citealpnum\ provides textual citations where superscript citations are the default.
+% These should be accessible via the \cmd\citet\ command.
+%
+% Therefore we remember how to do a numerical citation
+% even when the superscript citation has been selected.
+%    \begin{macrocode}
+\expandafter\DeclareRobustCommand
+\expandafter\rev@citet
+\expandafter{%
+ \expandafter\begingroup
+  \expandafter\rtx@swap@citea
+  \expandafter\g@bblefirsttoken
+              \csname citet \endcsname
+}%
+\expandafter\DeclareRobustCommand
+\expandafter\rev@citealp
+\expandafter{%
+ \expandafter\begingroup
+  \expandafter\rtx@swap@citea
+  \expandafter\g@bblefirsttoken
+              \csname citealp \endcsname
+}%
+\expandafter\DeclareRobustCommand
+\expandafter\rev@citealpnum
+\expandafter{%
+ \expandafter\begingroup
+  \expandafter\rtx@swap@citenum
+  \expandafter\g@bblefirsttoken
+              \csname citealp \endcsname
+}%
+\def\rtx@swap@citenum{%
+  \rtx@swap@citea
+  \let\@cite\NAT@citenum
+  \let\NAT@mbox\mbox
+  \let\citeyear\NAT@citeyear
+  \let\NAT@space\NAT@spacechar
+}%
+\def\g@bblefirsttoken{%
+ \expandafter\true@sw
+ \expandafter\@empty
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\rtx@citesuper}
+% We prepare to redefine \classname{natbib}'s procedure \cmd\NAT@citesuper,
+% which is executed when setting a superscript citation.
+% The \cmd\hspace\ is removed: in any case, it
+% should really be \cmd\hspace*, to prevent an unwanted pagebreak.
+%    \begin{macrocode}
+\newcommand\rtx@citesuper[3]{%
+ \ifNAT@swa
+  \leavevmode
+  \unskip
+% \hspace{1\p@}%
+  \textsuperscript{\normalfont#1}%
+  \if*#3*\else\ (#3)\fi
+ \else
+  #1%
+ \fi
+ \endgroup
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@makefnmark@cite}
+% We define a procedure that will set a footnote mark the same way that
+% a citation is set. If footnotes are put in the bibliography with
+% \cmd\footinbib@sw, then the corresponding mark should look the same
+% as the result of a \cmd\cite. This is how we do it.
+%    \begin{macrocode}
+\def\@makefnmark@cite{\begingroup\NAT@swatrue\@cite{{\@thefnmark}}{}{}}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\rtx@bibsection}
+% Prepare to override \classname{natbib}'s definition of \cmd\bibsection.
+%    \begin{macrocode}
+\def\rtx@bibsection{%
+ \@ifx@empty\refname{%
+  \par
+ }{%
+% \let\@hangfroms@section\@hang@froms
+  \expandafter\section\expandafter*\expandafter{\refname}%
+  \@nobreaktrue
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\rtx@swap@citea}
+% \begin{macro}{\rtx@def@citea}
+% \begin{macro}{\rtx@def@citea@close}
+% \begin{macro}{\rtx@def@citea@box}
+% The procedures |\rtx@def@citea|, |\rtx@def@citea@close|, and |\rtx@def@citea@box| 
+% can take over the management of \classname{natbib}'s |\@citea| macro to effect more sophisticated
+% behavior of the punctuation between textual citations. The switch is performed by \cmd\rtx@swap@citea.
+%
+% \changes{4.1j}{2009/10/25}{(AO, 552) Repair spacing in \cs{onlinecite}}
+% In these procedures, we use \cmd\count@\ to count the number of arguments of the \cmd\cite\ command,
+% and we use \cmd\c@NAT@ctr\ to keep track of which argument we are processing.
+% The latter counter is created by \classname{natbib} and used there solely in bibliography processing,
+% where it keeps track of the reference number. 
+% We take over its use in these macros, but only locally; therefore these procedures should work properly, even within the bibliography.
+%FIXME: check whether this is true!
+%
+% Because we are using a scratch counter \cmd\count@, we are vulnerable to other \TeX\ programmers
+% who patch in to \classname{natbib}'s processing and who might use that counter at the same time we are doing so.
+% This is a potential source of trouble for us. 
+%FIXME: store the value of \cmd\count@\ in a private \cmd\csname!
+%
+% Note that \cmd\rtx@def@citea\ begins the same as \cmd\NAT@def@citea, which it replaces, 
+% then makes further decisions based on the values of the counters. 
+%
+% Note also that, in \classname{natbib}, the replacement part of \cmd\NAT@def@citea@close\ could be rewritten as
+% \cmd\NAT@def@citea\cmd\prepdef\cmd\@citea\verb+{+\cmd\NAT@@close\verb+}+, which 
+% would them obviate the need for us to override its meaning. 
+%
+% Note, too, the effect of \cmd\rtx@def@citea@box, which replaces \cmd\NAT@def@citea@box,
+% is almost the same as the latter, except the entire \cmd\@citea\ is given as the argument
+% of \cmd\NAT@mbox.
+%
+% Finally, bear in mind that the English (and some American editors) do not place a comma
+% before the ``and''; our procedures do (but they could be rewritten with that convention). 
+%    \begin{macrocode}
+\def\rtx@swap@citea{%
+ \let\NAT@def@citea\rtx@def@citea
+ \let\NAT@def@citea@close\rtx@def@citea@close
+ \let\NAT@def@citea@box\rtx@def@citea@box
+}%
+\def\rtx@def@citea{%
+ \def\@citea{\NAT@separator\NAT@space}%
+ \advance\c@NAT@ctr\@ne
+ \@ifnum{\count@>\tw@}{%
+  \@ifnum{\c@NAT@ctr=\count@}{\appdef\@citea{\NAT@conj\NAT@space}}{}%
+ }{%
+  \def\@citea{\NAT@space\NAT@conj\NAT@space}%
+ }%
+}%
+\def\rtx@def@citea@close{%
+ \rtx@def@citea
+ \prepdef\@citea{\NAT@@close}%
+}%
+\def\rtx@def@citea@box{%
+ \rtx@def@citea@close
+ \expandafter\def\expandafter\@citea\expandafter{\expandafter\NAT@mbox\expandafter{\@citea}}%
+}%
+\def\NAT@conj{and}%
+%    \end{macrocode}
+%
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\BibitemShut}
+% \begin{macro}{\bibAnnote}
+% \changes{4.1j}{2009/10/24}{(AO, 549) Repairing natbib's \cs{BibitemShut} and \cs{bibAnnote}}
+% \changes{4.1o}{2010/02/05}{(AO, 549) Remove patch to natbib, which is now at version 8.31a}
+% \changes{4.1o}{2010/02/07}{(AO, 578) accommodate the possible space character preceding \cs{BibitemShut}.} 
+% We remember a temporary patch to \classname{natbib}'s definition of \cmd\BibitemShut.
+%    \begin{macrocode}
+\def\NAT@BibitemShut#1{%
+ \def\@bibstop{#1}%
+ \let\bibitem@Stop\bibitemStop
+ \let\bibitem@NoStop\bibitemNoStop
+ \@ifx{\bibitemShut\relax}{\let\@bibitemShut\@empty}{%
+  \expandafter\def\expandafter\@bibitemShut\expandafter{\bibitemShut}%
+ }%
+}%
+%    \end{macrocode}
+% The following is a bug fix to \classname{natbib} version 8.31b.
+%    \begin{macrocode}
+\def\BibitemShut@ltx#1{%
+ \unskip
+ \def\@bibstop{#1}%
+ \let\bibitem@Stop\bibitemStop
+ \let\bibitem@NoStop\bibitemNoStop
+ \@ifx{\bibitemShut\relax}{\let\@bibitemShut\@empty}{%
+  \expandafter\def\expandafter\@bibitemShut\expandafter{\bibitemShut}%
+ }%
+}%
+%    \end{macrocode}
+%
+%    \begin{verbatim}
+%\providecommand{\bibAnnote}[3]{%
+%  \BibitemShut{#1}%
+%  \def\@tempa{#3}\@ifx{\@tempa\@empty}{}{%
+%   \begin{quotation}\noindent
+%    \textsc{Key:}\ #2\\\textsc{Annotation:}\ \@tempa
+%   \end{quotation}%
+%  }%
+%  \ignorespaces
+%}%
+%\def\@bibitemShut{}%
+%    \end{verbatim}
+% \end{macro}
+% \end{macro}
+%
+%
+%    \begin{macrocode}
+\newenvironment{thebibliography}{}{}%
+\let\@listi\@empty
+\appdef\rtx@require@packages{%
+ \RequirePackage[sort&compress]{natbib}[2009/11/07 8.31a (PWD, AO)]%
+ \let@environment{NAT@thebibliography}{thebibliography}%
+ \let@environment{thebibliography}{rtx@thebibliography}%
+ \let\bibliographystyle@latex\bibliographystyle
+ \let\NAT@citesuper\rtx@citesuper
+%    \end{macrocode}
+%
+% \begin{macro}{\NAT@bibsetnum}
+% \begin{macro}{\NAT@bibsetup}
+% \begin{macro}{\bibpreamble}
+% \begin{macro}{\newblock}
+% \begin{macro}{\bibnumfmt}
+% \begin{macro}{\NAT@merge}
+% We define the sectioning command to use when starting the bibliography
+% and gently coax \classname{natbib} into using
+% the formatting procedures that \emph{we} want it to use.
+%
+% This way of setting up \env{thebibliography} 
+% automatically sets the label width based on
+% the largest number used within the bibliography.
+% This scheme will not work properly using the
+% author/year style of bib entry, though.
+%
+% We define \cmd\bibnumfmt\ to be \cmd\place@bibnumber, which is a macro
+% managed by \revtex. If the document defines \cmd\bibnumfmt, then that
+% definition will be used instead, which is what the \classname{natbib}
+% package gives as its programming interface.
+%
+% We set \cmd\NAT@merge\ to \cmd\tw@, which turns on \classname{natbib}'s
+% \classname{mcite} capabilities. This is the default setting. 
+% If numerical citations are not to be used, then \cmd\NAT@merge\ 
+% should be set to \cmd\@ne\ (syntax is still enabled, but semantics are turned off). 
+%    \begin{macrocode}
+\let\bibsection\rtx@bibsection
+\let\NATx@bibsetnum\NAT@bibsetnum
+\def\NAT@bibsetnum#1{%
+ \setlength{\topsep}{\z@}%
+ \NATx@bibsetnum{\ref{LastBibItem}}%
+}%
+\let\NATx@bibsetup\NAT@bibsetup
+\def\NAT@bibsetup{%
+ \setlength{\labelwidth}{\z@}%
+ \setlength{\labelsep}{\z@}%
+ \setlength{\itemindent}{\z@}%
+ \setlength{\listparindent}{\z@}%
+ \setlength{\topsep}{\z@}%
+ \setlength{\parsep}{\z@}%
+ \NATx@bibsetup
+}%
+\let\bibpreamble\@empty
+\def\newblock{\ }%
+\let\NATx@bibnumfmt\bibnumfmt
+\def\bibnumfmt{\place@bibnumber}%
+\let\NAT@merge\thr@@
+\let\NAT@citeyear\citeyear
+\let\onlinecite\rev@citealp
+\let\textcite\rev@citet
+%    \end{macrocode}
+% The following is needed until \classname{natbib} is at 8.31b.
+%    \begin{macrocode}
+\@ifx{\BibitemShut\NAT@BibitemShut}{%
+ \class@info{Repairing natbib's \string\BibitemShut}%
+ \let\BibitemShut\BibitemShut@ltx
+}{}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\bibliographystyle}
+% \changes{4.1q}{2010/04/01}{(AO, 586) When .bbl is pasted into the document, prevent automatic bibliography inclusion.}%
+% \changes{4.1q}{2010/04/13}{(AO, 588) Only write \revtex-specific BibTeX .bib data if the .bst style is set by REVTeX.}%
+% We arrange for the selection of bibliography style
+% to occur either due to the document's explicit
+% \cmd\bibliographystyle\ statement or
+% via the journal substyle.
+%
+% Note that \revtex\ is incompatible with 
+% any package that patches \cmd\bibliographystyle.
+% Since \classname{natbib} does this, we need a fix.
+%
+% The Boolean \cmd\bibliographystyle@sw\ signifies that the document  contains explicit
+% \cmd\bibliographystyle\ markup. If, on the contrary, the bibliography style is set by
+% the the society or the journal, then no explicit \cmd\bibliographystyle\ command appears in the document instance.
+% In this case \cmd\bibliographystyle@sw\ will be \cmd\false@sw.
+%    \begin{macrocode}
+\let\bibliographystyle@latex\bibliographystyle
+\def\bibliographystyle{\@booleantrue\bibliographystyle@sw\def\@bibstyle}%
+\@booleanfalse\bibliographystyle@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \changes{4.1j}{2009/11/03}{(AO, 551) Punctuation at end of reference when optional arguments to the cite key are given.}
+% The following had been bug fixes to \classname{natbib} version 8.31a.
+%    \begin{verbatim}
+%\def\bibitemStop{\@bibitemShut}%
+%\def\NAT@bibitem@cont{%
+% \let\bibitem@Stop\bibitemContinue
+% \let\bibitem@NoStop\bibitemContinue
+%}%
+%    \end{verbatim}
+% The following are alterations to \classname{natbib} version 8.31a to 
+% accommodate the possible space character preceding \cmd\BibitemShut,
+% and to handle the case of merged references, where the first ends with a stop character. 
+% \changes{4.1o}{2010/02/07}{(AO, 578) accommodate the possible space character preceding \cs{BibitemShut}.} 
+% \changes{4.1o}{2010/02/09}{(AO, 581) Handle case: merged references, with first ending in a stop character.} 
+%    \begin{macrocode}
+\def\NAT@bibitem@cont{%
+ \let\bibitem@Stop\bibitemContinue@Stop
+ \let\bibitem@NoStop\bibitemContinue
+}%
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\bibitemNoStop{%
+ \@ifx@empty\@bibitemShut{.\spacefactor\@mmm\space}{\@bibitemShut}%
+}%
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\bibitemContinue{%
+ \@ifx@empty\@bibitemShut{;\spacefactor\@mmm\space}{\@bibitemShut}%
+}%
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\bibitemContinue@Stop{%
+ \@ifx@empty\@bibitemShut{\spacefactor\@mmm\space}{\@bibitemShut}%
+}%
+%    \end{macrocode}
+%
+% \changes{4.1k}{2009/11/11}{(AO, 561) remove dead code relating to \cs{bibitemContinue}} 
+% We used to customize one of the productions of \classname{natbib}, but no longer.
+%    \begin{verbatim}
+%\let\bibitemContinue\bibitemContinue@rtx
+%    \end{verbatim}
+%
+% Here ends the code to be executed at \cmd\rtx@require@packages\ time.
+%    \begin{macrocode}
+}%
+%    \end{macrocode}
+% \changes{4.1f}{2009/07/07}{(AO, 516) Merged references are separated with a semicolon}
+% Redefine a macro of \classname{natbib} so that merged references are separated with a semicolon.
+% \changes{4.1k}{2009/11/11}{(AO, 561) remove dead code relating to \cs{bibitemContinue}} 
+%    \begin{verbatim}
+% \def\bibitemContinue@rtx{;\spacefactor\@mmm\space}%
+%    \end{verbatim}
+%
+% \begin{macro}{\onlinecite}
+% \begin{macro}{\textcite}
+% We extend \classname{natbib}'s syntax with two commands to set a citation
+% on the baseline (as opposed to superscripted) and as text (rather than parenthetical), respectively.
+% A journal substyle that makes citations be superscripted or parenthetical as the case may be, should ensure
+% that the author has continued access to these two styles. 
+%
+% Note that the society or journal substyle override the meanings of \cmd\@onlinecite\ or
+% \cmd\@textcite\ given here.
+% 
+%    \begin{macrocode}
+\DeclareRobustCommand\onlinecite{\@onlinecite}%
+\DeclareRobustCommand\textcite{\@textcite}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\bibliography}
+% \changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+% Provide a hook for supplying Bib\TeX\ a bibliographic database that may contain, say, 
+% footnotes.
+% 
+% Note that Bib\TeX\ chokes if the argument of the \cmd\bibdata\ command has null fields,
+% hence these tests.
+%    \begin{macrocode}
+\let\bibliography@latex\bibliography
+\def\bibliography#1{%
+ \auto@bib@empty
+ \begingroup
+  \let\auto@bib@innerbib\@empty
+  \@ifx@empty{\pre@bibdata}{%
+   \bibliography@latex{#1}%
+  }{%
+   \@if@empty{#1}{%
+    \expandafter\bibliography@latex\expandafter{\pre@bibdata}%
+   }{%
+    \expandafter\bibliography@latex\expandafter{\pre@bibdata,#1}%
+   }%
+  }%
+ \endgroup
+}%
+\let\pre@bibdata\@empty
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{environment}{rtx@thebibliography}%
+% \begin{macro}{\present@bibnote}%
+% \changes{4.1f}{2009/07/11}{(AO, 521) Lonely bibliography head}%
+% \changes{4.1n}{2010/01/02}{(AO, 572) Independent footnote counter for title block. Abstract footnote counter shared with body.}%
+% \changes{4.1o}{2010/02/02}{(AO, 575) Automatically incorporate the (Bib\TeX-generated) .bbl into an explicit \env{thebibliography}}%
+% \changes{4.1q}{2010/04/01}{(AO, 586) When .bbl is pasted into the document, prevent automatic bibliography inclusion.}%
+% We put a tail patch into \cmd\thebibliogrphy\ and
+% a headpatch into \cmd\endthebibliography.
+%
+% Here we provide a default treatment for frontmatter notes 
+% deferred to the bibliography; a journal substyle 
+% might want to override the definition of \cmd\present@bibnote.
+%
+% We make provisions for the case where there are no \cmd\bibitem s 
+% for the bibliography: we produce no bibliography head at all.
+% 
+%    \begin{macrocode}
+\newenvironment{rtx@thebibliography}[1]{%
+ \NAT@thebibliography{#1}%
+ \let\@TBN@opr\present@bibnote
+ \@FMN@list
+}{%
+%    \end{macrocode}
+% The following line was commented out:
+%    \begin{verbatim}
+%\@endnotesinbib
+%    \end{verbatim}
+% The \cmd\auto@bib@innerbib\ directive has been moved from the begin processing to the end processing.
+% This means that the content of the \env{thebibliography} environment can itself prevent the 
+% automatic reading in of the .bbl file. This would be needed when the user has pasted in the 
+% content of the .bbl file into the document itself, something required by APS and AIP editorial direction.
+%    \begin{macrocode}
+ \auto@bib@innerbib
+ \edef\@currentlabel{\arabic{NAT@ctr}}%
+ \label{LastBibItem}%
+ \endNAT@thebibliography
+ \aftergroup\auto@bib@empty
+}%
+\def\present@bibnote#1#2{%
+ \item[%
+  \textsuperscript{%
+   \normalfont
+   \Hy@raisedlink{\hyper@anchorstart{frontmatter.#1}\hyper@anchorend}%
+   \begingroup
+    \csname c@\@mpfn\endcsname#1\relax
+    \frontmatter@thefootnote
+   \endgroup
+  }%
+ ]#2\par
+%    \end{macrocode}
+% The following line was commented out:
+%    \begin{verbatim}
+%\global\let\NAT@bibitem@first@sw\@secondoftwo
+%    \end{verbatim}
+%    \begin{macrocode}
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{environment}
+%
+% \begin{macro}{write@bibliographystyle}
+% \changes{4.1q}{2010/04/13}{(AO, 588) Only write \revtex-specific BibTeX .bib data if the .bst style is set by REVTeX.}%
+% We wish to delay committing the \cmd\bibliographystyle\ until as late as possible.
+% The journal substyle will define a default bibliography style, and 
+% the document's explicit \cmd\bibliographystyle\ command, if any, will override that default.
+%
+% The \cmd\bibstyle\ command is allowed appear quite late in the \file{.aux} file. 
+% We now delay the automatic writing of the \cmd\bibstyle\ command to the end of the job.
+%
+% The procedure \cmd\write@bibliographystyle\ tests whether a \cmd\bibliographystyle\ command has 
+% already been given.
+% If not, it effectively executes the needed \cmd\bibliographystyle\ command, then neutralizes itself
+% (we only need to do this once per job).
+%
+% If the document lacks explicit \cmd\bibliographystyle\ markup, we execute
+% \cmd\@bibdataout@rev, a hook for \revtex-aware processing. 
+%    \begin{macrocode}
+\def\write@bibliographystyle{%
+ \@ifxundefined\@bibstyle{}{%
+  \expandafter\bibliographystyle@latex\expandafter{\@bibstyle}%
+  \bibliographystyle@sw{}{\@bibdataout@rev}%
+ }%
+ \global\let\write@bibliographystyle\relax
+}%
+\AtEndDocument{\write@bibliographystyle}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\rtx@@citetp}
+% \begin{macro}{\rtx@citex}
+% \begin{macro}{\super@cite@let}
+% \begin{macro}{\super@cite@end}
+% \begin{macro}{\super@cite@swap}
+% We wish to extend \classname{natbib} to move spaces and citations around
+% a superscript-style citation, imitating Donald Arseneau's \classname{cite} package
+% with the \classoption{super}.
+%
+% The \cmd\rtx@@citetp\ procedure is substituted for \cmd\NAT@@citetp;
+% it then calls the \cmd\rtx@citex\ procedure and implements the features of the
+% \classoption{citeautoscript} class option.
+% In the end, \cmd\@citex\ is called with its customary parameters. 
+%
+% The document should be marked up as if citations were \emph{not} superscripted,
+% and then if you select a journal substyle that has superscripted citations, \revtex\ will do its best
+% to alter the formatting of the \cmd\cite s to accomodate superscript style.
+%
+% Only citations set as superscript are affected by this procedure,
+% because we check \cmd\@cite\ against \cmd\NAT@citesuper. 
+%
+% Here's a subtle point: when is the argument of \cmd\super@cite@swap\ not the same as the token \cmd\@let@token?
+% Answer: when the latter is \cmd\@sptoken! This case has to be handled separately.
+% 
+% Note that whether a punctuation is movable is determined by the definition
+% of a particular control sequence name.
+% A society or journal can alter things: to remove a character from the set,
+% do, say, \cmd\expandafter \cmd\let \cmd\csname \texttt{rtx@automove;} \cmd\endcsname \cmd\relax.
+% To add a character to the set, do, say, \cmd\expandafter \cmd\let \cmd\csname \texttt{rtx@automove;} \cmd\endcsname \cmd\@empty.
+%
+% Implementation note: due to a \TeX\ peculiarity, we have to check for the case
+% where \cmd\@let@token\ is a space token \emph{before} we parse forward.
+% At issue is the corner case where an end of file is at hand. If we 
+% were to let \cmd\super@cite@swap\ parse forward, we would encounter a \TeX\ end-of-file
+% error. Note that the test will be true in many distinct cases:
+% the file ends, the next character is a line terminator, the next character is a space.
+%    \begin{macrocode}
+\def\rtx@@citetp[#1]{\@ifnextchar[{\rtx@citex[#1]}{\rtx@citex[][#1]}}%
+\def\rtx@citex[#1][#2]#3{%
+ \begingroup
+  \def\@tempa{[#1][#2]{#3}}%
+  \@ifx{\@cite\NAT@citesuper}{%
+   \leavevmode
+   \skip@\lastskip
+   \unskip
+   \super@cite@let
+  }{%
+   \super@cite@end
+  }%
+}%
+\def\super@cite@let{%
+ \futurelet\@let@token\super@cite@check
+}%
+\def\super@cite@end{%
+ \aftergroup\@citex\expandafter\endgroup\@tempa
+}%
+\def\super@cite@check{%
+ \@ifx{\@let@token\@sptoken}{%
+  \super@cite@end
+ }{%
+  \super@cite@swap
+ }%
+}%
+\long\def\super@cite@swap#1{%
+ \expandafter\@ifx\expandafter{\csname rtx@automove#1\endcsname\@empty}{%
+  #1%
+  \super@cite@let
+ }{%
+  \super@cite@end
+  #1%
+ }%
+}%
+\expandafter\let\csname rtx@automove.\endcsname\@empty
+\expandafter\let\csname rtx@automove,\endcsname\@empty
+\expandafter\let\csname rtx@automove:\endcsname\@empty
+\expandafter\let\csname rtx@automove;\endcsname\@empty
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% The following must execute only after \classname{natbib} is loaded and has set
+% up its parameters (which it does at \cmd\AtBeginDocument\ time).
+% If superscript citations have been selected, and 
+% if the \classoption{citeautoscript} class option has been selected, 
+% we patch into \classname{natbib}'s mechanism to migrate punctuation around the 
+% citation, as in class \classname{cite} with the \classoption{superscript} option.
+%    \begin{macrocode}
+\appdef\class@documenthook{%
+ \citeautoscript@sw{%
+  \@ifx{\@cite\NAT@citesuper}{%
+   \let\NAT@@citetp\rtx@@citetp
+  }{}%
+ }{}%
+}%
+%    \end{macrocode}
+%
+% Resolve an incompatability between \classname{natbib} and \classname{listings}.
+% The latter package tests \cmd\chapter (which has now been \cmd\let\ to \cmd\relax\ as a side effect \classname{natbib}'s use of \LaTeX's \cmd\@ifundefined).
+%
+% We couch our fix in such terms that will not be disruptive if \cmd\chapter\ is actually defined at this point.
+%
+% \changes{4.1b}{2008/07/01}{(AO) No longer need to test \cs{chapter} as of \texttt{natbib} version 8.2}
+%    \begin{verbatim}
+%\@ifx{\chapter\relax}{\let\chapter\@undefined}{}%
+%    \end{verbatim}
+%
+%
+% \subsubsection{\cs{endnote}s and \cs{rtx@bibnote}s}
+%
+% \begin{macro}{\mini@note}
+% \begin{macro}{\save@note}
+% \changes{4.1n}{2010/01/02}{(AO, 572) Independent footnote counter for title block. Abstract footnote counter shared with body.}%
+% QUERY: how do footnotes get thrown to the bibliography. \cmd\footinbib@sw\ appears to be irrelevant. 
+%    \begin{macrocode}
+\def\mini@note{\save@note\mini@notes}%Implicit #2
+\def\save@note#1#2{%
+  \stepcounter\@mpfn
+  \protected@xdef\@thefnmark{\thempfn}%
+  \@footnotemark
+  \expandafter\g@addto@macro
+  \expandafter#1%
+  \expandafter{%
+  \expandafter \@@footnotetext
+  \expandafter {\@thefnmark}{#2}%
+              }%
+}%
+\long\def\@@footnotetext#1{\def\@thefnmark{#1}\@footnotetext}%
+\let\mini@notes\@empty
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\endnote}
+% A version of footnote that appears in the bibliography, or where \cmd\printendnotes\ appears.
+%    \begin{verbatim}
+%\def\@endnote{%
+% \begingroup
+%  \aftergroup\@footnotemark
+%  \aftergroup\@endnotetext
+%  \@ifnextchar[{%
+%   \@xendnote
+%  }{%
+%   \stepcounter{footnote}%
+%   \protected@xdef\@tempa{\thefootnote}%
+%   \expandafter\@xendnote\expandafter[\the\c@footnote]%
+% }%
+%}%
+%    \end{verbatim}
+% \end{macro}
+%
+% \begin{macro}{\@xendnote}
+% \changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+% \begin{verbatim}
+%\def\unused@xendnote[#1]{%
+%  \begingroup
+%   \c@footnote#1\relax
+%    \end{macrocode}
+% New for 4.1
+%    \begin{macrocode}
+%   \unrestored@protected@xdef\@endnotelabel{Note\thefootnote}%
+%   \authoryear@sw{%
+%    \unrestored@protected@xdef\@thefnmark{\noexpand\ref{\@endnotelabel}}%
+%   }{%
+%    \unrestored@protected@xdef\@thefnmark{\@endnotelabel}%
+%   }%
+%    \end{macrocode}
+% Was:
+% \unrestored@protected@xdef\@thefnmark{endnote\thefootnote}%
+% End 4.1 changes
+%    \begin{macrocode}
+%  \endgroup
+% \endgroup
+%}%
+%\def\@endnotemark{%
+% \expandafter\cite\expandafter{\@thefnmark}%
+%}%
+% \end{verbatim}
+%    \begin{macrocode}
+\def\rev@citemark#1{%
+ \expandafter\cite\expandafter{\@thefnmark}%
+}%
+\def\rev@endtext#1{%
+ \let\@endnotelabel\@thefnmark
+ \@endnotetext
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\endnote@ext}
+% \begin{macro}{\bibdata@app}
+% \begin{macro}{\bibdata@ext}
+% The macro \cmd\endnote@ext\ is the file extension for the auxiliary file holding footnotes.
+% The \cmd\bibdata@app\ and \cmd\bibdata@ext\ macros are used to form the name of a
+% Bib\TeX\ database file holding footnotes.
+%    \begin{macrocode}
+\def\endnote@ext{.end}%
+\def\bibdata@app{Notes}%
+\def\bibdata@ext{bib}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@endnotetext}
+% \changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+% The procedure \cmd\@endnotetext\ writes a Bib\TeX\ .bib file for the purpose
+% of insering a footnote into the (numbered, unsorted) bibliography.
+%
+% We need to define \cmd\pre@bibdata\ to be 
+% \cmd\jobname\cmd\endnote@ext, and we probably should define \cmd\endnote@ext\ to 
+% be something like ``Notes.bib''.
+%
+% In each case, the material to be written out requires robustification, provided by \cmd\endnote@relax.
+% The commands \cmd\label, \cmd\index, and \cmd\glossary,
+% which are robustified for \cmd\markright\ and \cmd\addcontentsline,
+% are likewise robustified here.
+%
+% Procedure \cmd\@endnotetext@note\ is the alias for \cmd\@endnotetext\ when the endnotes are to be
+% processed separately from the bibliography (generally true when citations are not sorted).
+%    \begin{verbatim}
+%\long\def\unused@endnotetext@note#1{%
+%  \@ifxundefined\@endnoteout{%
+%    \newwrite\@endnoteout
+%    \gdef\endnote@stream{\jobname\endnote@ext}%
+%    \immediate\openout\@endnoteout\endnote@stream\relax
+%  }{}%
+%  \begingroup
+%    \endnote@relax
+%    \immediate\write\@endnoteout{\string\@doendnote{\@endnotelabel}{#1}}%
+%  \endgroup
+%}%
+%    \end{verbatim}
+%
+% \cmd\@doendnote\ is obsolete.
+%    \begin{verbatim}
+%\def\@doendnote#1#2{\bibitem{#1}#2}%
+%    \end{verbatim}
+%
+% \changes{4.1o}{2010/02/05}{(AO, 579) Endnote shall comprise their own Bib\TeX\ entry type: @FOOTNOTE.} 
+% Procedure \cmd\@endnotetext\ is the operative procedure\ when the endnotes are to be
+% collated in with the other references, typically true when numerical citations are being used.
+% The technique involves writing a .bib file (\cmd\@bibdataout) with each endnote typed as 
+% a \texttt{@FOOTNOTE} entry. 
+%
+% Timing note: doing \cmd\openout\ should be deferred until the beginning of the document,
+% as is done here. This allows one to make a format (\filename{.fmt}) file out of this class.
+%    \begin{macrocode}
+\long\def\@endnotetext#1{%
+  \begingroup
+    \endnote@relax
+    \immediate\write\@bibdataout{%
+     @FOOTNOTE{%
+      \@endnotelabel,%
+%    \end{macrocode}
+% The \texttt{key} field is recommended in cases where there is no author (see \filename{btxdoc}).
+%    \begin{macrocode}
+      key="\@endnotelabel",%
+%    \end{macrocode}
+% The \texttt{note} field is simply the content of the footnote.
+%    \begin{macrocode}
+      note="#1"%
+     }%
+    }%
+  \endgroup
+}%
+\newwrite\@bibdataout
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\endnote@relax}
+% At \cmd\AtBeginDocument\ time, we open the job's \filename{.bib} file.
+%
+% Procedure \cmd\endnote@relax\ robustifies commands that ought not to be expanded when
+% the endnote is written out.
+% Note the similarity between \cmd\endnote@relax\ and  \cmd\protected@write.
+%    \begin{macrocode}
+\def\endnote@relax{%
+ \let\label\relax \let\index\relax \let\glossary\relax
+ \let\cite \relax \let\ref  \relax \let\pageref \relax
+ \let\(    \relax \let\)    \relax \let\\       \relax
+ \let~\relax
+%    \end{macrocode}
+%    \begin{verbatim}
+%\let\protect\noexpand
+%    \end{verbatim}
+%    \begin{macrocode}
+ \let \protect \@unexpandable@protect
+ \newlinechar`\^^M%
+%    \end{macrocode}
+%    \begin{verbatim}
+%\newlinechar`\ %
+%    \end{verbatim}
+%    \begin{macrocode}
+ \let\begin\relax \let\end\relax
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@bibdataout@init}
+% \begin{macro}{\@bibdataout@aps}
+% \changes{4.1o}{2010/02/10}{(AO, 580) Provide a document class option to turn off production of eprint field in bibliography.} 
+% \changes{4.1o}{2010/02/12}{(AO, 580) Control .bst at run time.}%
+% \changes{4.1q}{2010/04/13}{(AO, 588) Only write \revtex-specific BibTeX .bib data if the .bst style is set by REVTeX.}%
+%\changes{4.2b}{2018/12/26}{(MD) Improve control over display of e-print ids in bibliography.}%
+% At \cmd\AtBeginDocument\ time, we open the job's \filename{.bib} file.
+% The hook is available for use by a society to place its own @CONTROL record in the \cmd\@bibdataout\ stream.
+%    \begin{macrocode}
+\appdef\class@documenthook{\@bibdataout@init}%
+\def\@bibdataout@init{%
+ \immediate\openout\@bibdataout\pre@bibdata.\bibdata@ext\relax
+}%
+\def\@bibdataout@rev{%
+ \immediate\write\@bibdataout{%
+%    \end{macrocode}
+% The entry that controls processing of the \filename{.bst} file has entry type \texttt{@CONTROL}. 
+% The citation key (REVTEX42Control) is effectively a version number,
+% which the \filename{.bst} can use to interpret the bib entry.
+%    \begin{macrocode}
+  @CONTROL{%
+   REVTEX42Control%
+%    \end{macrocode}
+% Say if we want the \texttt{eprint} field disabled. Otherwise accept the default of the \filename{.bst}. 
+%    \begin{macrocode}
+   \eprint@enable@sw{}{,eprint="1"}%
+  }%
+ }%
+%    \end{macrocode}
+% Place a \cmd\citation\ into the auxiliary file corresponding to this entry. 
+%    \begin{macrocode}
+ \if@filesw
+  \immediate\write\@auxout{\string\citation{REVTEX42Control}}%
+ \fi
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\printendnotes}
+% \changes{4.1f}{2009/07/10}{(AO, 520) Automatically produce \cs{bibliography} command when needed}%
+% We have removed the endnotes facility from REVTeX, so the \cmd\printendnotes\ command now does nothing.
+%
+% Moving footnotes to the bibliogrphy is now accomplished through 
+% the automatic generation of a job BiB\TeX\ database (called \cmd\pre@bibdata) containing the footnotes.
+%    \begin{macrocode}
+\def\printendnotes{%
+ \class@warn{The \string\printendnotes\space command no longer serves any function. Please remove it from your document.}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@endnotesinbib}
+% \begin{macro}{\@endnotesinbibliography}
+% \changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+% We define a function \cmd\@endnotesinbib,
+% and a variant \cmd\@endnotesinbibliography.
+% The former is invoked at the start of 
+% the end processing for \enve{thebibliography};
+% the latter is a synonym.
+%
+% The procedure typesets the footnotes that are to 
+% appear in the bibliography; the default is to
+% simply arrange for the footnote counter to be
+% reset at the start of the document.
+%
+% Note that this code make the assumption that 
+% the counter used in \env{thebibliography} is \cmd\c@NAT@ctr.
+% \changes{4.1f}{2009/07/10}{(AO, 520) Automatically produce \cs{bibliography} command when needed}%
+%
+% Here is the sole place where \cmd\footinbib@sw\ has an effect, other code simple assigning its value.
+% If it is false, or \cmd\authoryear@sw\ is true, then footnotes are handled by the default mechanism.
+%    \begin{macrocode}
+\def\make@footnote@endnote{%
+ \footinbib@sw{%
+  \authoryear@sw{}{%
+   \ltx@footnote@push
+   \def\thempfn{Note\thefootnote}%
+   \let\ltx@footmark\rev@citemark
+   \let\ltx@foottext\rev@endtext
+%    \end{macrocode}
+% The endnotes facility has been removed. 
+% Also, there is no need to queue up \cmd\auto@bib\ here, since it is always queued up elsewhere. 
+% \changes{4.1f}{2009/07/10}{(AO, 520) Automatically produce \cs{bibliography} command when needed}%
+%    \begin{verbatim}
+%  \appdef\class@enddocumenthook{\auto@bib}%
+%  \let\printendnotes\relax
+%    \end{verbatim}
+%    \begin{macrocode}
+  }%
+ }{}%
+}%
+%    \end{macrocode}
+% 
+%    \begin{macrocode}
+\def\ltx@footnote@push{%
+ \let\ltx@footmark@latex\ltx@footmark
+ \let\ltx@foottext@latex\ltx@foottext
+ \let\thempfn@latex\thempfn
+ \def\ltx@footnote@pop{%
+  \let\ltx@footmark\ltx@footmark@latex
+  \let\ltx@foottext\ltx@foottext@latex
+  \let\thempfn\thempfn@latex
+ }%
+}%
+%    \end{macrocode}
+%
+% The switchover to setting footnotes in the bibliography
+% changes the meaning of \cmd\footnote\ and
+% substitutes the synonym for \cmd\@endnotesinbib. 
+%
+% We arrange for the procedure \cmd\make@footnote@endnote\ to be executed
+% at \cmd\class@documenthook\ time (we mustn't do this earlier because
+% the meaning of \cmd\@footnotemark\ must not be changed before then, 
+% for the sake of \file{ltxutil.dtx}).
+%    \begin{macrocode}
+\appdef\class@documenthook{%
+ \make@footnote@endnote
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\auto@bib}
+% \begin{macro}{\auto@bib@empty}
+% \begin{macro}{\test@bbl@sw}
+% \begin{macro}{\bibitem@set}
+% \begin{macro}{\auto@bib@innerbib}
+% \begin{macro}{\thebibliography@nogroup}
+% \changes{4.1f}{2009/07/10}{(AO, 520) Automatically produce \cs{bibliography} command when needed}%
+% \changes{4.1n}{2010/01/02}{(AO, 572) Independent footnote counter for title block. Abstract footnote counter shared with body.}%
+% \changes{4.1o}{2010/02/02}{(AO, 575) Automatically incorporate the (Bib\TeX-generated) .bbl into an explicit \env{thebibliography}}%
+% Under some circumstances, we must typeset the bibliography automatically.
+% If the document requires footnotes to be  set in the bibliography (effectively, class option \texttt{footinbib}), 
+% or that frontmatter footnotes be set in the bibliography (effectively, class option \texttt{bibnotes}), 
+% but contains no explicit \cmd\bibliography\ statement.
+%
+% Note that this facility is not able to work more than once per document.
+% If multiple bibliographys are required (e.g., per article), it will be the responsibility of the journal style
+% to restore \cmd\auto@bib\ to its original meaning so it can be re-invoked.
+% 
+% In procedure \cmd\auto@bib, we first test for the presence of frontmatter footnotes deferred to the bibliography.
+% If none, we further test for the presence of \cmd\bibitem\ commands in the job's \filename{.bbl} file.
+% If either condition is met, we ask for a bibliography. 
+% We know that the document itself lacks a \cmd\bibliography\ statement, 
+% so we know the argument of the \cmd\bibliography\ that we will issue.
+%    \begin{macrocode}
+\def\auto@bib{%
+ \@ifx@empty\@FMN@list{%
+  \footinbib@sw{%
+   \@ifnum{\csname c@\@mpfn\endcsname>\z@}{%
+    \true@sw
+   }{%
+    \test@bbl@sw
+   }%
+  }{%
+   \test@bbl@sw
+  }%
+ }{%
+  \true@sw
+ }%
+ {%
+  \bibliography{}%
+ }{}%
+}%
+\def\auto@bib@empty{%
+ \let\auto@bib\@empty
+}%
+%    \end{macrocode}
+% Testing the \filename{.bbl} file involves defanging all expected commands
+% and processing that file inside a box register (that will be simply discarded).
+% We provide a new meaning for the \cmd\bibitem\ command: it queues a Boolean.
+%    \begin{macrocode}
+\def\test@bbl@sw{%
+ \setbox\z@\vbox\bgroup
+  \let\providecommand\providecommand@j@nk
+  \let\bibfield\@gobbletwo
+  \let\bibinfo\@gobbletwo
+  \let\translation\@gobble
+  \let\BibitemOpen\@empty
+  \let\bibitemStop\@empty
+  \let\bibitemNoStop\@empty
+  \let\EOS\@empty
+  \let\BibitemShut\@gobble
+  \let\bibAnnoteFile\@gobbletwo
+  \let\bibAnnote\@gobblethree
+  \let\textbf\@gobble
+  \let\emph\@gobble
+  \@booleanfalse\bibitem@sw
+  \let\bibitem\bibitem@set
+  \auto@bib@innerbib
+  \bibitem@sw{\aftergroup\true@sw}{\aftergroup\false@sw}%
+ \egroup
+}%
+%    \end{macrocode}
+% The \cmd\bibitem@set\ is an alias for \cmd\bibitem\ for the purpose of detecting a non-trivial bibliography.
+%    \begin{macrocode}
+\newcommand\bibitem@set[1][]{%
+ \bibitem@sw{}{%
+  \@booleantrue\bibitem@sw
+  \aftergroup\@booleantrue\aftergroup\bibitem@sw
+ }%
+}%
+%    \end{macrocode}
+% The \cmd\auto@bib@innerbib\ procedure reads in the \filename{.bbl} file (if it exists)
+% within a context where its \env{thebibliography} environment does nothing, not even establishing a group. 
+%    \begin{macrocode}
+\def\auto@bib@innerbib{%
+ \begingroup
+  \let@environment{thebibliography}{thebibliography@nogroup}%
+  \bibliography{}%
+ \endgroup
+}%
+%    \end{macrocode}
+% Environment \env{thebibliography@nogroup} is an alias of the \env{thebibliography} environment that cancels itself. 
+% It assumes that it is called within a \env{thebibliography} environment. 
+%    \begin{macrocode}
+\def\thebibliography@nogroup#1{%
+ \endgroup
+ \def\@currenvir{thebibliography}%
+}%
+\def\endthebibliography@nogroup{\begingroup}%
+%    \end{macrocode}
+% The following should be part of \filename{ltxutil}.
+%    \begin{macrocode}
+\long\def \@gobblethree #1#2#3{}%
+\def\providecommand@j@nk#1[#2]{%
+ \@ifnum{#2=\z@}{\def\j@nk}{%
+  \@ifnum{#2=\@ne}{\def\j@nk##1}{%
+   \@ifnum{#2=\tw@}{\def\j@nk##1##2}{%
+    \@ifnum{#2=\thr@@}{\def\j@nk##1##2##3}{%
+    }%
+   }%
+  }%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \section{Initial setup}
+% 
+% The standard LaTeX document classes execute certain commands 
+% that are best deferred until \cmd\class@documenthook\ time.
+% Here, we effectively split \cmd\pagenumbering\ into two halves,
+% with a default definition for \cmd\thepage
+% and an initialization of \cmd\c@page\ at \cmd\class@documenthook\ time.
+%
+% The meaning of \cmd\thepage\ can be overridden by society, journal, or
+% anywhere within the document pramble, and the counter itself will be 
+% preset at the beginning of the document. 
+%    \begin{macrocode}
+\def\thepage{\@arabic\c@page}%
+%    \end{macrocode}
+% \changes{4.0b}{1999/06/20}{Defer assignment until \cs{AtBeginDocument} time.}
+% Note that this code is executed at \cmd\setup@hook\ time 
+% to allow for the possibility of overrides by packages like \classname{geometry}.
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \tabbingsep \labelsep
+ \leftmargin\leftmargini
+ \labelwidth\leftmargin\advance\labelwidth-\labelsep
+ \let\@listi\@listI
+ \@listi
+}%
+%    \begin{macrocode}
+%
+% We ensure that the ``environment'' component mark (implemented by \file{ltxgrid.dtx}) 
+% is initialized properly (via a hook, itself defined via \file{ltxutil.dtx}). 
+%    \begin{macrocode}
+\appdef\class@documenthook{%
+ \global\c@page\@ne
+ \def\curr@envir{document}%
+ \mark@envir{\curr@envir}%
+}%
+%    \end{macrocode}
+%
+% \begin{macro}{\open@onecolumn}%
+% \begin{macro}{\open@column@two}%
+% \changes{4.0c}{1999/11/13}{Grid changes with ltxgrid}
+% \changes{4.0d}{2000/04/10}{Also alter how lists get indented.}
+% When setting the column grid, we have to override the procedure
+% for formatting lists. 
+% Because \cmd\twocolumngrid\ requires rebalancing columns at some points, 
+% typesetting must employ only the manipulation of 
+% \cmd\leftskip\ and \cmd\rightskip, and must avoid the use of
+% \cmd\moveleft, \cmd\moveright, and \cmd\parshape. 
+%
+% It is one of the stranger features of \TeX\ that these two separate
+% mechanisms exist. The latter three have the effect of adding things to the 
+% Main Vertical List that cannot be removed and later added back with all their
+% properties intact.
+%
+% In detail, \cmd\moveleft, say, adds a box to the MVL with
+% its reference point shifted horizontally by some amount relative to the 
+% reference point of the enclosing list. If that box is removed from the 
+% MVL (via a \cmd\lastbox\ operation in the output routine), and later
+% thrown back to the MVL, the shift of the box will have been ``forgotten'' by \TeX.
+% This is a bug, but not one ``acceptible to D. E. Knuth'', so it will never be fixed. 
+%
+%    \begin{macrocode}
+\def\open@onecolumn{%
+ \open@column@one\@ne
+ \set@colht
+ \@floatplacement
+ \@dblfloatplacement
+}%
+\def\open@twocolumn{%
+ \open@column@mlt\tw@
+ \set@colht
+ \@floatplacement
+ \@dblfloatplacement
+ \sloppy
+ \let\set@listindent\set@listindent@
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \section{\cs{appendix}}
+%
+%    \begin{macrocode}
+%\newif\ifappendixon
+%    \end{macrocode}
+% Note that, within appendices, 
+% equations are numbered within sections (appendices).
+%    \begin{macrocode}
+\def\appendix{%
+ \par
+%\appendixontrue
+ \setcounter{section}\z@
+ \setcounter{subsection}\z@
+ \setcounter{subsubsection}\z@
+ \def\thesubsection{\arabic{subsection}}%
+ \def\thesubsubsection{\alph{subsubsection}}%
+ \@addtoreset{equation}{section}%
+ \def\theequation@prefix{\thesection}%
+ \addtocontents{toc}{\protect\appendix}%
+ \@ifstar{%
+  \def\thesection{\unskip}%
+  \def\theequation@prefix{A.}%
+ }{%
+  \def\thesection{\Alph{section}}%
+ }%
+}%
+%    \end{macrocode}
+%
+% \section{Changing the page grid}
+% \changes{4.0b}{1999/06/20}{Define three separate environments, defer assignment to \cs{AtBeginDocument} time.}
+%
+% \subsection{Avoiding Grid Changes}%
+%
+% In preprint styles, ``wide text'' is a no-op, and the title page
+% processing involves no grid change.
+% 
+% \begin{macro}{\title@column}%
+% \begin{macro}{\close@column}%
+% Provide default meanings for \cmd\title@column\ and \cmd\close@column,
+% in case they were never defined. 
+% Note that the society or journal substyle may define 
+% \cmd\title@column\ or \cmd\close@column: this code will not override. 
+%    \begin{macrocode}
+\def\title@column#1{%
+ \minipagefootnote@init
+ #1%
+ \minipagefootnote@foot
+}%
+\def\close@column{%
+ \newpage
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsection{Galley Style: Margin Changes}%
+% A variant of preprint processing. Emulate journal appearance somewhat.
+%
+% \begin{environment}{widetext@galley}
+% DPC: We're in galley style so do a lob sided display environment.
+%
+% QUERY: How can we be sure that we are in galley style?
+% ANSWER: as noted elsewhere, require that both \cmd\twocolumn@sw\ and \cmd\preprintsty@sw\ be false.
+%    \begin{macrocode}
+\def\galley@outdent{\rightmargin-\columnwidth\advance\rightmargin-\columnsep}%
+\let\widetext@outdent\@empty
+\newenvironment{widetext@galley}{%
+  \list{}{%
+    \topsep        \z@skip
+    \listparindent \parindent
+    \itemindent    \parindent
+    \leftmargin    \z@
+    \parsep        \z@\@plus\p@
+    \widetext@outdent
+    \relax
+  }%
+  \item\relax
+}{
+  \endlist
+}%
+%    \end{macrocode}
+% \end{environment}
+%
+%
+% \subsection{Grid Changing Via \classname{ltxgrid}}%
+%
+% In case \classoption{twocolumngrid} has been invoked,
+% switch column grid using the column grid-changing commands.
+% Supply stub definitions of those commands here.
+% \changes{4.0c}{1999/11/13}{grid changes with ltxgrid}
+%
+% \begin{macro}{\title@column@grid}%
+% \begin{macro}{\close@column@grid}%
+% The title block always starts at the top of a new page.
+% \changes{4.0c}{1999/11/13}{grid changes with ltxgrid}
+%
+% Note that, for the procedure \cmd\close@column@grid,
+% we balance columns by switching to the one-column page grid. 
+%    \begin{macrocode}
+\def\title@column@grid#1{%
+ \minipagefootnote@init
+  \onecolumngrid
+  \begingroup
+   \let\@footnotetext\frontmatter@footnotetext
+%<ignore>  \let\set@footnotewidth\set@footnotewidth@two
+   \ltx@no@footnote
+   #1%
+  \endgroup
+  \twocolumngrid
+ \minipagefootnote@foot
+}%
+\def\close@column@grid{%
+ \balancelastpage@sw{%
+  \onecolumngrid
+%<ignore>  \twocolumngrid
+ }{}%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{environment}{widetext@grid}
+% \changes{4.0c}{1999/11/13}{grid changes via ltxgrid procedures}
+% \changes{4.0e}{2000/11/21}{adornments above and below.}
+% \changes{4.1g}{2009/10/07}{(AO, 525) Remove phantom paragraph above display math that is given in vertical mode}%
+% We slip into the one-column page grid
+% within the scope of this environment.
+%
+% Note that we set adornments above and below the \env{widettext}.
+% These are set as leaders, so they will disappear at a page break.
+% \changes{4.1n}{2010/01/02}{(AO) fine-tune spacing above and below widetext}%
+%    \begin{macrocode}
+\newenvironment{widetext@grid}{%
+  \par\ignorespaces
+  \setbox\widetext@top\vbox{%
+%<ignore>  \vskip15\p@
+   \hb@xt@\hsize{%
+    \leaders\hrule\hfil
+    \vrule\@height6\p@
+   }%
+%<ignore>  \vskip6\p@
+  }%
+  \setbox\widetext@bot\hb@xt@\hsize{%
+    \vrule\@depth6\p@
+    \leaders\hrule\hfil
+  }%
+  \onecolumngrid
+  \vskip10\p@
+  \dimen@\ht\widetext@top\advance\dimen@\dp\widetext@top
+  \cleaders\box\widetext@top\vskip\dimen@
+%<ignore> \let\set@footnotewidth\set@footnotewidth@two
+  \vskip6\p@
+  \prep@math@patch
+}{%
+  \par
+  \vskip6\p@
+  \setbox\widetext@bot\vbox{%
+   \hb@xt@\hsize{\hfil\box\widetext@bot}%
+%<ignore>  \vskip14\p@
+  }%
+  \dimen@\ht\widetext@bot\advance\dimen@\dp\widetext@bot
+  \cleaders\box\widetext@bot\vskip\dimen@
+  \vskip8.5\p@
+  \twocolumngrid\global\@ignoretrue
+  \@endpetrue
+}%
+\newbox\widetext@top
+\newbox\widetext@bot
+%    \end{macrocode}
+% \end{environment}
+%
+%
+% Decide, finally, how the page grid is to be manipulated.
+%    \begin{macrocode}
+\def\set@page@grid{%
+ \twocolumn@sw{%
+%    \end{macrocode}
+% The following two assignments determine what procedures are to be executed when 
+% the footnote set width is calculated, and how footnotes are to be composed at the bottom of the page. 
+% A society or journal wishing to do otherwise will override this code. 
+%    \begin{macrocode}
+  \let\set@footnotewidth\set@footnotewidth@two
+  \let\compose@footnotes\compose@footnotes@two
+  \let@environment{widetext}{widetext@grid}%
+  \let\title@column\title@column@grid
+  \let\close@column\close@column@grid
+ }{%
+  \let@environment{widetext}{widetext@galley}%
+  \preprintsty@sw{%
+%    \end{macrocode}
+% Change the page grid not at all.
+%    \begin{macrocode}
+  }{%
+%    \end{macrocode}
+% If we are galley style, change the page margin only.
+%    \begin{macrocode}
+   \galley@sw{%
+    \let\widetext@outdent\galley@outdent
+   }{}%
+  }%
+ }%
+}%
+\appdef\setup@hook{\set@page@grid}%
+%    \end{macrocode}
+%
+% \section{Old font commands}
+%
+%    \begin{macrocode}
+\DeclareOldFontCommand{\rm}{\normalfont\rmfamily}{\mathrm}
+\DeclareOldFontCommand{\sf}{\normalfont\sffamily}{\mathsf}
+\DeclareOldFontCommand{\tt}{\normalfont\ttfamily}{\mathtt}
+\DeclareOldFontCommand{\bf}{\normalfont\bfseries}{\mathbf}
+\DeclareOldFontCommand{\it}{\normalfont\itshape}{\mathit}
+\DeclareOldFontCommand{\sl}{\normalfont\slshape}{\@nomath\sl}
+\DeclareOldFontCommand{\sc}{\normalfont\scshape}{\@nomath\sc}
+\DeclareRobustCommand*\cal{\@fontswitch\relax\mathcal}
+\DeclareRobustCommand*\mit{\@fontswitch\relax\mathnormal}
+%    \end{macrocode}
+%
+% \section{English-Language Texts}
+% As this class is just for English language journals, we
+% could hardwire these texts,
+% but to make it easier to use this as a
+% basis for the code for similar journal styles, separate out all the
+% fixed text strings into babel-style macros of the form 
+% |\|\ldots|name|
+%
+% Note: for babel compatability, use version 1999/05/05 v3.6x or later.
+%
+% Some of these might need changing in the society-specific code.
+%
+% \begin{macro}{\today}
+% Procedure \cmd\today\ is used in the article class, but not in 
+% this document class.
+%    \begin{macrocode}
+\def\today{\ifcase\month\or
+  January\or February\or March\or April\or May\or June\or
+  July\or August\or September\or October\or November\or December\fi
+  \space\number\day, \number\year}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\notesname}
+% Text entity \cmd\notesname\ had been used in \cmd\printendnotes.
+% \changes{4.1f}{2009/07/10}{(AO, 520) Automatically produce \cs{bibliography} command when needed}%
+% However, we have removed the endnotes facility from REVTeX.
+% 
+%    \begin{verbatim}
+%\def\notesname{Notes}
+%    \end{verbatim}
+%    \end{macro}
+%
+% \begin{macro}{\partname}
+% Text entity \cmd\partname\ is used in \cmd\@part.
+%    \begin{macrocode}
+\def\partname{Part}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\tocname}
+% Text entity \cmd\tocname\ is used in \cmd\tableofcontents,
+% as defined in the standard \LaTeX\ book class.
+%    \begin{macrocode}
+\def\tocname{Contents}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\lofname}
+% Text entity \cmd\lofname\ is used in \cmd\listoffigures,
+% as defined in the standard \LaTeX\ book class.
+%    \begin{macrocode}
+\def\lofname{List of Figures}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\lotname}
+% Text entity \cmd\lotname\ is used in \cmd\listoftables,
+% as defined in the standard \LaTeX\ book class.
+%    \begin{macrocode}
+\def\lotname{List of Tables}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\refname}
+% Text entity \cmd\refname\ is used in \env{thebibliography}.
+%    \begin{macrocode}
+\def\refname{References}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\indexname}
+% Text entity \cmd\indexname\ is used in \env{theindex},
+% as defined in the standard \LaTeX\ book class.
+%    \begin{macrocode}
+\def\indexname{Index}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\figurename}
+% \changes{4.0b}{1999/06/20}{Added localization of \cs{figuresname}}
+% Text entity \cmd\figurename\ is used in \env{figure},
+% \cmd\figuresname\ in \cmd\printfigures.
+%    \begin{macrocode}
+\def\figurename{FIG.}
+\def\figuresname{Figures}%
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\tablename}
+% \changes{4.0b}{1999/06/20}{Added localization of \cs{tablesname}}
+% Text entity \cmd\tablename\ is used in \env{table},
+% \cmd\tablesname\ in \cmd\printtables.
+%    \begin{macrocode}
+\def\tablename{TABLE}
+\def\tablesname{Tables}%
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\abstractname}
+% Text entity \cmd\abstractname\ is used in \env{abstract}.
+%    \begin{macrocode}
+\def\abstractname{Abstract}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\appendixesname}
+% \begin{macro}{\appendixname}
+% Text entity \cmd\appendixesname\ is used in TOC.
+%    \begin{macrocode}
+\def\appendixesname{Appendixes}%
+\def\appendixname{Appendix}%
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+% \begin{macro}{\acknowledgmentsname}
+% Text entity \cmd\acknowledgmentsname\ is used in \env{acknowledgments}.
+%    \begin{macrocode}
+\def\acknowledgmentsname{Acknowledgments}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\journalname}
+% This should be set by the society journal options, eg `pra'.
+%    \begin{macrocode}
+\def\journalname{??}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\copyrightname}
+% Default layout does not assign copyright, but a journal that wants
+% to might use this.
+%    \begin{macrocode}
+\def\copyrightname{??}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\andname}
+% The text string ``and'' for use in author lists.
+%    \begin{macrocode}
+\def\andname{and}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\@pacs@name}
+% \begin{macro}{\@keys@name}
+% The text string prepended to PACS numbers, resp. to keywords.
+%    \begin{macrocode}
+\def\@pacs@name{PACS numbers: }%
+\def\@keys@name{Keywords: }%
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+% \begin{macro}{\ppname}
+% The text string ``pp'' for use in page ranges.
+%    \begin{macrocode}
+\def\ppname{pp}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\numbername}
+% The text string ``number'' for use in article reference.
+%    \begin{macrocode}
+\def\numbername{number}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\volumename}
+% The text string ``volume'' for use in article reference.
+%    \begin{macrocode}
+\def\volumename{volume}
+%    \end{macrocode}
+%    \end{macro}
+%
+% \begin{macro}{\Dated@name}
+% \begin{macro}{\Received@name}
+% \begin{macro}{\Revised@name}
+% \begin{macro}{\Accepted@name}
+% \begin{macro}{\Published@name}
+% These texts are used in the \cmd\date, et al. commands.
+%    \begin{macrocode}
+\def\Dated@name{Dated: }%
+\def\Received@name{Received }%
+\def\Revised@name{Revised }%
+\def\Accepted@name{Accepted }%
+\def\Published@name{Published }%
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%    \end{macro}
+%    \end{macro}
+%    \end{macro}
+%
+% \section{Legacy Commands}
+% We define some commands left over from version 3.1, or give default meanings.
+% Some definitions can be overridden
+% in the document preamble or in included packages.
+%
+% Note on the namespace: command names like \cmd\REV@\emph{name} are used here,
+% because it is not clear that any of this code is generally useful.
+%    \begin{macrocode}
+\def\address{\replace@command\address\affiliation}%
+\def\altaddress{\replace@command\altaddress\altaffiliation}%
+\newenvironment{references}{%
+ \class@warn@end{The references environment is not supported; use thebibliography instead.}
+ \gdef\references{\thebibliography{}}\references
+}{%
+ \endthebibliography
+}%
+\def\draft{%
+ \class@warn@end{Command \string\draft\space is obsolete;^^JInvoke option draft instead.}%
+ \@booleantrue\draft@sw
+}%
+\def\tighten{%
+ \class@warn@end{Command \string\tighten\space is obsolete;^^JInvoke option tightenlines instead.}%
+ \@booleantrue\tightenlines@sw
+}%
+\def\tableline{%
+ \noalign{%
+  \class@warn@end{Command \string\tableline\space is obsolete;^^JUse \string\colrule\space instead.}%
+  \global\let\tableline\colrule
+ }%
+ \tableline
+}%
+\def\case{\replace@command\case\frac}%
+\def\slantfrac{\replace@command\slantfrac\frac}%
+\def\tablenote{\replace@command\tablenote\footnote}%
+\def\tablenotemark{\replace@command\tablenotemark\footnotemark}%
+\def\tablenotetext{\replace@command\tablenotetext\footnotetext}%
+% Lose the following definition:
+\DeclareRobustCommand\REV@text[1]{%
+ \relax
+ \ifmmode
+  \mathchoice
+   {\hbox{{\everymath{\displaystyle     }#1}}}%
+   {\hbox{{\everymath{\textstyle        }#1}}}%
+   {\hbox{{\everymath{\scriptstyle      }\let\f@size\sf@size\selectfont#1}}}%
+   {\hbox{{\everymath{\scriptscriptstyle}\let\f@size\ssf@size\selectfont#1}}}%
+  \glb@settings
+ \else
+  \mbox{#1}%
+ \fi
+}%
+% Lose the following definition:
+\DeclareRobustCommand\REV@bbox[1]{%
+ \relax
+ \ifmmode
+  \mathchoice
+   {\hbox{{\everymath{\displaystyle     }\boldmath$#1$}}}%
+   {\hbox{{\everymath{\textstyle        }\boldmath$#1$}}}%
+   {\hbox{{\everymath{\scriptstyle      }\boldmath$#1$}}}%
+   {\hbox{{\everymath{\scriptscriptstyle}\boldmath$#1$}}}%
+  \glb@settings
+ \else
+  \mbox{#1}%
+ \fi
+}%
+\DeclareRobustCommand\REV@bm[1]{%
+ \class@warn@end{To use \string\bm, please load the bm package!}%
+ \global\let\bm\relax
+}%
+\def\FL{\obsolete@command\FL}%
+\def\FR{\obsolete@command\FR}%
+\def\narrowtext{\obsolete@command\narrowtext}%
+\def\mediumtext{\obsolete@command\mediumtext}%
+\newenvironment{quasitable}{%
+ \let@environment{tabular}{longtable}%
+}{%
+}%
+%    \end{macrocode}
+%
+% \begin{macro}{\text}
+% \begin{macro}{\bm}
+% \begin{macro}{\bibinfo}
+% \begin{macro}{\eprint}
+% \begin{macro}{\url}
+% 
+% If not otherwise defined, give default meanings to certain commands.
+% \changes{4.0d}{2000/04/10}{eprint takes an optional argument, syntactical only in this case.}
+%FIXME: \cmd\bibinfo?
+%    \begin{macrocode}
+\let\text\REV@text
+\let\bm\REV@bm
+\appdef\setup@hook{%
+ \providecommand\bibinfo[2]{#2}%
+ \providecommand\eprint[2][]{#2}%
+%\providecommand\url[1]{#1}%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\bbox}
+% 
+%    \begin{macrocode}
+\def\bbox#1{%
+ \class@warn@end{\string\bbox\space is obsolete,^^Jload the bm package and use \string\bm\space instead.}%
+ \global\let\bbox\relax
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\mathletters}
+%
+%    \begin{macrocode}
+\newenvironment{mathletters}{%
+ \class@warn@end{Environment {mathletters} is obsolete;^^Jload the amsmath package and use {subequations}!}%
+ \global\let\mathletters\@empty
+}{%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\eqnum}
+% 
+%    \begin{macrocode}
+\def\eqnum#1{%
+ \class@warn@end{\string\eqnum\space is obsolete, load the amsmath package and use \string\tag!}%
+ \global\let\eqnum\@gobble
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% We read in the symbol definitions.
+%    \begin{macrocode}
+\appdef\rtx@require@packages{%
+ \RequirePackage{revsymb4-2}%
+}%
+\appdef\class@documenthook{\revsymb@inithook}%
+%    \end{macrocode}
+%
+%
+% \section{Corrected Indentation for \texttt{tableofcontents}}
+% \changes{4.2a}{2014/12/31}{(MD, Aptara) Make titles in bibliography default, prb style to follow other Phys. Rev. journals, add a unified physrev option as well as prx, prapplied, prmaterials, prfluids, prab, and prper options. Corrected indentation for tableofcontents appearing along with listoffigure/listoftable.}%
+%
+% Corrected indentation for \texttt{tableofcontents}, when appearing with \texttt{listoffigure} or \texttt{listoftable}.
+%
+%    \begin{macrocode}
+%%
+\def\@startflt#1{%
+  \begingroup
+    %\toc@pre
+    \makeatletter
+    \@input{\jobname.#1}%
+    \if@filesw
+      \expandafter\newwrite\csname tf@#1\endcsname
+      \immediate\openout \csname tf@#1\endcsname \jobname.#1\relax
+    \fi
+    \@nobreakfalse
+    %\toc@post
+  \endgroup
+}%
+\def\att@TOC{toc}%
+\def\print@toc#1{%
+ \begingroup
+  \expandafter\section
+  \expandafter*%
+  \expandafter{%
+              \csname#1name\endcsname
+              }%
+  \let\appendix\appendix@toc
+  \def\tempa{#1}%
+  \ifx\tempa\att@TOC%%
+  \@starttoc{#1}%
+  \else%%
+  \@startflt{#1}%%
+  \fi%%
+ \endgroup
+}%
+%%
+%    \end{macrocode}
+%
+%
+% \section{Patches for lineno.sty}
+%
+% The \classname{lineno} package detects the case where the package has been loaded
+% and the document invokes \cmd\linelabel, but the \cmd\linenumbers\ command has not been
+% issued: it treats this case as an error. 
+%
+% It is wrong for validity of document syntax to be dependent upon package semantics: 
+% we make the condition a warning rather than an error.  
+% 
+%    \begin{macrocode}
+\def\@LN@LLerror@org{%
+ \PackageError{lineno}{%
+  \string\linelabel\space without \string\linenumbers
+ }{% 
+  Just see documentation. (New feature v4.11)%
+ }%
+ \@gobble
+}%
+\def\@LN@LLerror@ltx{%
+ \PackageWarning{lineno}{%
+  To make the \string\linelabel\space command work, you must issue the \string\linenumbers\ command 
+ }%
+ \@gobble
+}%
+%    \end{macrocode}
+% 
+% If appropriate, enable line numbering within the abstract. 
+%
+% This mechanism applies generally:
+% Create the box in a context in which the meaning of \cmd\par\ has been patched by \classname{lineno},
+% then \cmd\unvbox\ the box in a context where \cmd\set@linepenalties\ has been executed, and 
+% follow up with \cmd\@linenumberpar, which forces a visit to the output routine just there.
+% Note that here, we have to de-fang \cmd\@LN@parpgbrk, which would otherwise causes the appearance
+% of a box with depth -1000 points. Go figure.
+%    \begin{macrocode}
+\appdef\class@documenthook{%
+ \@ifx{\@LN@LLerror\@LN@LLerror@org}{%
+  \class@info{Overriding \string\@LN@LLerror}%
+  \let\@LN@LLerror\@LN@LLerror@ltx
+ }{}%
+ \@ifpackageloaded{lineno}{%
+  \@ifxundefined{\set@linepenalties}{}{%
+   \def\prep@absbox{\set@linepenalties}%
+   \def\post@absbox{\let\@LN@parpgbrk\@empty\@linenumberpar}%
+  }%
+ }{}%
+}%
+%    \end{macrocode}
+%
+% One may well ask: how to obtain line numbering within an alignment in a float?
+% This objective, along with line numbering within footnotes, would require extraordinary measures.
+% The float would have to be thrown onto the MVL in order to acquire its line numbers, but
+% that fragment of MVL would then have to be protected from being shipped out.
+% The question of how to coordinate those lines' numbers with those of lines in the MVL would 
+% also require dealing with.
+%
+% \section{Endgame for the Document Class}
+%
+% We provide for a ``job macro package'' that can override
+% definitions and assignments made by the class or any other packages it loads.
+%
+% \subsection{Job Macro Package}
+% You can create a ``job macro package'' for your document
+% that will be read in automatically every time
+% your document is processed.
+% Thus, if your job is a file called \file{myarticle.tex},
+% then the file \file{myarticle.rty} will be read in
+% just the same as if you had placed a 
+% \cmd\usepackage|{myarticle.rty}| statement
+% immediately following your \cmd\documentclass\ statement.
+%
+% Within your \file{.rty} file,
+% you can define and use control sequence names that use the |@| character
+% and you can override any of the definitions or assignments made 
+% by the \revtex\ document class or the selected journal substyle.
+% That is, you have the power to really mess things up badly.
+%
+% If you choose to have a job macro package, you are well 
+% advised to read the \LaTeX\ guide to document classes,
+% \file{clsguide.tex} or read up on the subject 
+% in a book like the \LaTeX\ Companion.
+%
+% The file \file{template.rty} contains a template for
+% creating your own job macro package.
+%
+%    \begin{macrocode}
+\appdef\rtx@require@packages{%
+ \InputIfFileExists{\jobname.rty}{}{}%
+}%
+%    \end{macrocode}
+%
+% \subsection{Endgame Processing for the Document Class}
+%
+% The remaining steps in processing the document class involve
+% determining the needed society, journal, and pointsize from 
+% the document's class options and inputting the needed files or
+% executing the indicated procedures. 
+%
+% Note that the society file is expected to declare options that will
+% allow us to determine the journal involved, and the society and journal
+% themselves determine the which pointsize options are declared, along with
+% their meanings. 
+% 
+% Note also that required packages are read in only after the document options
+% have been processed, because the latter can affect the former. 
+% 
+% Finally, the setup code is executed: this is code that depends on the 
+% meanings of the switches we define and on the code within the packages we load. 
+%
+% Note that there are other hooks in use: \cmd\document@inithook, which is 
+% executed right at the beginning of the document, and \cmd\class@documenthook, 
+% which serves as a vehicle for any \cmd\AtBeginDocument\ code we might wish to
+% execute. 
+%
+%FIXME: use \cmd\class@documenthook\ only for things that bear on the MVL; 
+% use \cmd\document@inithook\ for all patches to procedures defined within the preamble. 
+%
+% Remember that \classname{natbib} changes its state at \cmd\AtBeginDocument\ time,
+% so we have to install our own code at a later point in the processing.
+%
+% We determine the proper \cmd\@society\ by examining the document's class options. 
+%    \begin{macrocode}
+\@parse@class@options@society
+%    \end{macrocode}
+%
+% Then, we input the society's substyle
+% (which may in turn lead to loading a journal substyle or a pointsize substyle). 
+% The substyle should not assume the value of any class option: 
+% instead, it should install code into \cmd\setup@hook. 
+%    \begin{macrocode}
+\@process@society{aps}%
+%    \end{macrocode}
+%
+% Now that the society has defined the class options relating to journals,
+% and has defined \cmd\@journal@default, we can process the journal substyle. 
+% We parse the options for one that sets \cmd\@journal.
+%    \begin{macrocode}
+\@parse@class@options@\@journal
+%    \end{macrocode}
+% And we process the journal. 
+% Note that \emph{it is an error} for a society file to fail to define
+% \cmd\@journal@default.
+%
+%    \begin{macrocode}
+\expandafter\@process@journal\expandafter{\@journal@default}%
+%    \end{macrocode}
+%
+% Now that the society and journal have finished defining any options relating to 
+% point size, we process the class options for any that set \cmd\@pointsize.
+%    \begin{macrocode}
+\@parse@class@options@\@pointsize
+%    \end{macrocode}
+% And we process the pointsize.
+% Note that it is an error for the society and journal to leave \cmd\@pointsize@default\ 
+% undefined at this point, however, the journal may have overriden the assignment of the society. 
+%
+%    \begin{macrocode}
+\expandafter\@process@pointsize\expandafter{\@pointsize@default}%
+%    \end{macrocode}
+%
+% Next, we process the class options for once and all. 
+% Doing so sets values for some of the Booleans that were introduced along with
+% the \cmd\DeclareOption\ statements above. 
+%
+%CHANGE: We process the options in the order declared in the document; this 
+% gives the document greater control. 
+%
+%    \begin{macrocode}
+\@options
+%    \end{macrocode}
+% 
+% Now that the class options have been processed, we can load all the 
+% packages that we know need loading.
+%    \begin{macrocode}
+\rtx@require@packages
+%    \end{macrocode}
+%
+% At this point, the society substyle, the journal substyle, and the 
+% pointsize have all been processed, along with the document class options.
+% Some of these have left things for later; we do these now.
+%
+% \begin{macro}{\setup@hook}
+%
+% This portion of the code for this class file
+% \emph{must} appear at the very end:
+% The procedure 
+% \cmd\setup@hook\
+% should be executed at the very end of the class file. 
+% Any code that relies on the value of any of the \texttt{@sw} switches
+% or will patch the code of one of the required packages
+% should be executed here. 
+%\changes{4.2a}{2017/11/28}{(MD) Add call to \normalsize to be a good citizen and allow booktabs.sty to work properly}
+%
+%    \begin{macrocode}
+\appdef\setup@hook{\normalsize}%
+\setup@hook
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% Warn if past maturation date. This code to be enabled only in beta software.
+% \changes{4.1f}{2009/07/11}{(AO, 522) Warn if software is expired}%
+% \changes{4.1h}{2009/10/09}{(AO) Remove expiry code in the release software}%
+%    \begin{macrocode}
+%<*ignore>
+ \def\rtx@fin@year{2010}%
+ \def\rtx@fin@month{01}%
+ \def\rtx@fin@day{01}%
+ \def\rtx@fin@warn{%
+  \@ifnum{\rtx@fin@year>\the\year\relax}{\true@sw}{%
+   \@ifnum{\rtx@fin@month>\the\month\relax}{\true@sw}{%
+    \@ifnum{\rtx@fin@day>\the\day\relax}{\true@sw}{%
+     \false@sw
+    }%
+   }%
+  }%
+  {%
+   \class@info{Beta software expires \rtx@fin@year-\rtx@fin@month-\rtx@fin@day; updates available at https://journals.aps.org/revtex/}%
+  }{%
+   \class@warn{Outdated software expired \rtx@fin@year-\rtx@fin@month-\rtx@fin@day; please retrieve an update at https://journals.aps.org/revtex/}%
+  }%
+ }%
+%</ignore>
+%    \end{macrocode}
+% In shipping (non-beta) software, the following line should be commented out.
+% \changes{4.1f}{2009/07/11}{(AO, 522) Warn if software is expired}%
+%    \begin{verbatim}
+%\appdef\class@enddocumenthook{\rtx@fin@warn}%
+%    \end{verbatim}
+%
+% End of the class file.
+%    \begin{macrocode}
+%</package>
+%    \end{macrocode}
+%
+%
+% \section{Symbols: the \texttt{revsymb} module}
+% We immediately define a utility command: this module's warning.
+%    \begin{macrocode}
+%<*revsymb>
+\def\REVSYMB@warn#1{\PackageWarningNoLine{revsymb}{#1}}%
+%    \end{macrocode}
+%
+% \begin{macro}{\lambdabar}
+%    \begin{macrocode}
+\DeclareRobustCommand\lambdabar{%
+  \bgroup
+    \def\@tempa{%
+      \hbox{%
+        \raise.73\ht\z@
+        \hb@xt@\z@{%
+          \kern.25\wd\z@
+          \vrule \@width.5\wd\z@\@height.1\p@\@depth.1\p@
+          \hss
+        }%
+        \box\z@
+      }%
+    }%
+    \mathchoice
+      {\setbox\z@\hbox{$\displaystyle     \lambda$}\@tempa}%
+      {\setbox\z@\hbox{$\textstyle        \lambda$}\@tempa}%
+      {\setbox\z@\hbox{$\scriptstyle      \lambda$}\@tempa}%
+      {\setbox\z@\hbox{$\scriptscriptstyle\lambda$}\@tempa}%
+  \egroup
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\openone}
+% DPC: Really should use a font that includes this glyph.
+% Unfortunately not in AMS ones, but is in bbold, cmbb.
+% (I think, must check),
+% \changes{4.0a}{1998/01/31}{use font-dependent spacing}
+% FIXME: check for bbold.
+%    \begin{macrocode}
+\DeclareRobustCommand\openone{\leavevmode\hbox{\small1\normalsize\kern-.33em1}}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\corresponds}
+% \begin{macro}{\overdots}
+% \begin{macro}{\overcirc}
+% J\"org Knappen suggests the replacements:
+% replace \cmd\corresponds\ with \cmd\triangleq, source \classname{amssymb};
+% replace \cmd\overcirc\ with \cmd\mathring, source \classname{latex2e};
+% replace \cmd\overdots\ with \cmd\dddot, source \classname{amsmath}.
+%
+% Any use of any of these commands will result in a warning message at the end 
+% of the log file. If the corresponding package is not loaded, a
+% definition will quietly be provided.
+%    \begin{macrocode}
+\DeclareRobustCommand\corresponds{\replace@command\corresponds\triangleq}%
+\DeclareRobustCommand\overcirc{\replace@command\overcirc\mathring}%
+\DeclareRobustCommand\overdots{\replace@command\overdots\dddot}%
+\DeclareRobustCommand\REV@triangleq{%
+ {\lower.2ex\hbox{=}}{\kern-.75em^\triangle}%
+}%
+\DeclareRobustCommand\REV@dddot[1]{%
+ \@ontopof{#1}{\cdots}{1.0}\mathord{\box2}%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\succsim}
+% \begin{macro}{\precsim}
+% \begin{macro}{\lesssim}
+% \begin{macro}{\gtrsim}
+% \begin{macro}{\alt}
+% \begin{macro}{\agt}
+% These version 3.1 commands are always supplied, 
+% but the definitions in \classname{amssymb} are preferred.
+%    \begin{macrocode}
+\DeclareRobustCommand\altsuccsim{\succ\kern-.9em_\sim\kern.3em}%
+\DeclareRobustCommand\altprecsim{\prec\kern-1em_\sim\kern.3em}%
+\let\REV@succsim\altsuccsim
+\let\REV@precsim\altprecsim
+\DeclareRobustCommand\REV@lesssim{\mathrel{\mathpalette\vereq{<}}}%
+\DeclareRobustCommand\REV@gtrsim{\mathrel{\mathpalette\vereq{>}}}%
+\DeclareRobustCommand\alt{\lesssim}
+\DeclareRobustCommand\agt{\gtrsim}
+\def\vereq#1#2{%
+ \lower3\p@\vbox{%
+  \baselineskip1.5\p@
+  \lineskip1.5\p@
+  \ialign{$\m@th#1\hfill##\hfil$\crcr#2\crcr\sim\crcr}%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\tensor}
+% \begin{macro}{\overstar}
+% \begin{macro}{\loarrow}
+% \begin{macro}{\roarrow}
+% \changes{4.0b}{1999/06/20}{AO: remove duplicates}
+%    \begin{macrocode}
+\DeclareRobustCommand\tensor[1]{\@ontopof{#1}{\leftrightarrow}{1.15}\mathord{\box2}}
+\DeclareRobustCommand\overstar[1]{\@ontopof{#1}{\ast}{1.15}\mathord{\box2}}
+\DeclareRobustCommand\loarrow[1]{\@ontopof{#1}{\leftarrow}{1.15}\mathord{\box2}}
+\DeclareRobustCommand\roarrow[1]{\@ontopof{#1}{\rightarrow}{1.15}\mathord{\box2}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@ontopof}
+%    \begin{macrocode}
+\def\@ontopof#1#2#3{%
+ {%
+  \mathchoice
+    {\@@ontopof{#1}{#2}{#3}\displaystyle     \scriptstyle      }%
+    {\@@ontopof{#1}{#2}{#3}\textstyle        \scriptstyle      }%
+    {\@@ontopof{#1}{#2}{#3}\scriptstyle      \scriptscriptstyle}%
+    {\@@ontopof{#1}{#2}{#3}\scriptscriptstyle\scriptscriptstyle}%
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@ontopof}
+% Same as \revtex3, more or less.
+%    \begin{macrocode}
+\def\@@ontopof#1#2#3#4#5{%
+  \setbox\z@\hbox{$#4#1$}%
+  \setbox\f@ur\hbox{$#5#2$}%
+  \setbox\tw@\null\ht\tw@\ht\z@ \dp\tw@\dp\z@
+  \@ifdim{\wd\z@>\wd\f@ur}{%
+    \setbox\f@ur\hb@xt@\wd\z@{\hss\box\f@ur\hss}%
+    \mathord{\rlap{\raise#3\ht\z@\box\f@ur}\box\z@}%
+  }{%
+    \setbox\f@ur\hb@xt@.9\wd\f@ur{\hss\box\f@ur\hss}%
+    \setbox\z@\hb@xt@\wd\f@ur{\hss$#4\relax#1$\hss}%
+    \mathord{\rlap{\copy\z@}\raise#3\ht\z@\box\f@ur}%
+  }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frak}
+% Deal with legacy \cmd\frak:
+% if \classname{amsfonts} not loaded, defined in such a way as to ask for that package.
+% Also, says to use \cmd\mathfrak\ instead.
+%    \begin{macrocode}
+\DeclareRobustCommand\frak{%
+ \REVSYMB@warn{%
+  Command \string\frak\space unsupported:^^J%
+  please use \string\mathfrak\space instead.%
+ }%
+ \global\let\frak\mathfrak
+ \frak
+}%
+\DeclareRobustCommand\REV@mathfrak{%
+ \REVSYMB@warn{%
+  Command \string\mathfrak\space undefined:^^J%
+  please specify the amsfonts or amssymb option!%
+ }%
+ \global\let\mathfrak\@firstofone
+ \mathfrak
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\Bbb}
+% Deal with legacy \cmd\Bbb:
+% if \classname{amsfonts} not loaded, defined in such a way as to ask for that package.
+% Also, says to use \cmd\mathbb\ instead.
+%    \begin{macrocode}
+\DeclareRobustCommand\Bbb{%
+ \REVSYMB@warn{%
+  Command \string\Bbb\space unsupported:^^J%
+  please use \string\mathbb\space instead.%
+ }%
+ \global\let\Bbb\mathbb
+ \Bbb
+}%
+\DeclareRobustCommand\REV@mathfrak{%
+ \REVSYMB@warn{%
+  Command \string\mathbb\space undefined:^^J%
+  please specify the amsfonts or amssymb option!%
+ }%
+ \global\let\mathbb\@firstofone
+ \mathbb
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\Bigglb}
+% Deal with legacy bold delimiters. 
+% Each of the following takes an implicit argument consisting of
+% the delimiter to be made big and bold.
+% FIXME: \cmd\DeclareBoldMathCommand\ is not the right tool!
+%    \begin{macrocode}
+\def\Bigglb{\REV@boldopen \Bigg}%
+\def\Biglb {\REV@boldopen \Big }%
+\def\bigglb{\REV@boldopen \bigg}%
+\def\biglb {\REV@boldopen \big }%
+\def\Biggrb{\REV@boldclose\Bigg}%
+\def\Bigrb {\REV@boldclose\Big }%
+\def\biggrb{\REV@boldclose\bigg}%
+\def\bigrb {\REV@boldclose\big }%
+\def\REV@pmb#1{%
+ \hbox{%
+  \setbox\z@=\hbox{#1}%
+  \kern-.02em\copy\z@\kern-\wd\z@
+  \kern .04em\copy\z@\kern-\wd\z@
+  \kern-.02em
+  \raise.04em\copy\z@
+ }%
+}%
+\def\REV@boldopen #1#2{\mathopen {\REV@pmb{$#1#2$}}}%
+\def\REV@boldclose#1#2{\mathclose{\REV@pmb{$#1#2$}}}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\revsymb@inithook}
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% Package dependencies are taken care of at \cmd\setup@hook\ time.
+%    \begin{macrocode}
+\def\revsymb@inithook{%
+ \@ifxundefined\dddot{\let\dddot\REV@dddot}{}%
+ \@ifxundefined\triangleq{\let\triangleq\REV@triangleq}{}%
+ \@ifxundefined\succsim{\let\succsim\altsuccsim}{}%
+ \@ifxundefined\precsim{\let\precsim\altprecsim}{}%
+ \@ifxundefined\lesssim{\let\lesssim\REV@lesssim}{}%
+ \@ifxundefined\gtrsim {\let\gtrsim \REV@gtrsim }{}%
+ \@ifxundefined\mathfrak{\let\mathfrak\REV@mathfrak}{}%
+ \@ifxundefined\mathbb{\let\mathbb\REV@mathbb}{}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%    \begin{macrocode}
+%</revsymb>
+%    \end{macrocode}
+%
+% \section{The \classoption{10pt} class option: the \texttt{10pt} module}
+% \changes{4.0b}{1999/06/20}{AO: all code for \protect\classoption{10pt} is in this module.}
+% The file \file{aps10pt.rtx} is read in by the \classname{revtex4} document class
+% if \cmd\@pointsize\ has the value 10.
+%
+%    \begin{macrocode}
+%<*10pt>
+%    \end{macrocode}
+%
+% \subsection{Defend Against Forseeable Errors}%
+% Protect this file from being read in by anything but \revtex.
+%    \begin{macrocode}
+\ifx\undefined\substyle@ext
+ \def\@tempa{%
+  \endinput
+  \GenericWarning{I must be read in by REVTeX! (Bailing out)}%
+ }%
+ \expandafter\else
+  \def\@tempa{}%
+ \expandafter\fi\@tempa
+ \class@info{RevTeX pointsize 10pt selected}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\normalsize{%
+   \@setfontsize\normalsize\@xpt{11.5}%
+   \abovedisplayskip 10\p@ \@plus2\p@ \@minus5\p@
+   \belowdisplayskip \abovedisplayskip
+   \abovedisplayshortskip  \abovedisplayskip
+   \belowdisplayshortskip \abovedisplayskip
+   \let\@listi\@listI
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\small{%
+  \@setfontsize\small\@ixpt{10.5}%
+  \abovedisplayskip 8.5\p@ \@plus3\p@ \@minus4\p@
+  \belowdisplayskip \abovedisplayskip
+  \abovedisplayshortskip \z@ \@plus2\p@
+  \belowdisplayshortskip 4\p@ \@plus2\p@ \@minus2\p@
+  \def\@listi{%
+    \leftmargin\leftmargini
+    \topsep 4\p@ \@plus2\p@ \@minus2\p@
+    \parsep 2\p@ \@plus\p@ \@minus\p@
+    \itemsep \parsep
+  }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\footnotesize{%
+  \@setfontsize\footnotesize\@viiipt{9.5pt}%
+  \abovedisplayskip 6\p@ \@plus2\p@ \@minus4\p@
+  \belowdisplayskip \abovedisplayskip
+  \abovedisplayshortskip \z@ \@plus\p@
+  \belowdisplayshortskip 3\p@ \@plus\p@ \@minus2\p@
+  \def\@listi{%
+    \leftmargin\leftmargini
+    \topsep 3\p@ \@plus\p@ \@minus\p@
+    \parsep 2\p@ \@plus\p@ \@minus\p@
+    \itemsep \parsep
+  }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\scriptsize{%
+ \@setfontsize\scriptsize\@viipt\@viiipt
+}%
+\def\tiny{%
+ \@setfontsize\tiny\@vpt\@vipt
+}%
+\def\large{%
+ \@setfontsize\large\@xiipt{14pt}%
+}%
+\def\Large{%
+ \@setfontsize\Large\@xivpt{18pt}%
+}%
+\def\LARGE{%
+ \@setfontsize\LARGE\@xviipt{22pt}%
+}%
+\def\huge{%
+ \@setfontsize\huge\@xxpt{25pt}%
+}%
+\def\Huge{%
+ \@setfontsize\Huge\@xxvpt{30pt}%
+}%
+%    \end{macrocode}
+%
+% The values of these margin parameters are dependent upon 
+% \cmd\twoside@sw; any society or journal that 
+% has its own preferences should override these assignments
+% by doing \cmd\appdef\cmd\setup@hook.
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \twoside@sw{%
+%   \oddsidemargin  -.1in
+%   \evensidemargin -.4in
+    \oddsidemargin  -20pt
+    \evensidemargin -20pt
+    \marginparwidth 107pt
+ }{%
+    \oddsidemargin  -.25in
+    \evensidemargin -.25in
+    \marginparwidth 30pt
+ }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\marginparsep 6pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\topmargin -61pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\headheight 25pt
+\headsep 16pt
+%    \end{macrocode}
+%
+% \changes{4.1n}{2010/01/02}{(AO, 571) class file must set \cs{splittopskip}; fine tune \cs{skip}\cs{footins}; \cs{footnoterule} defined in terms of \cs{skip}\cs{footins}}%
+%    \begin{macrocode}
+\topskip 10pt
+\splittopskip\topskip
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\footskip 30pt
+%    \end{macrocode}
+% 
+%    \begin{macrocode}
+ \textheight = 56pc
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\textwidth42.5pc
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\columnsep 1.5pc
+\columnseprule 0pt
+%    \end{macrocode}
+%
+% \changes{4.1n}{2010/01/02}{(AO, 571) class file must set \cs{splittopskip}; fine tune \cs{skip}\cs{footins}; \cs{footnoterule} defined in terms of \cs{skip}\cs{footins}}%
+%    \begin{macrocode}
+\footnotesep 1pt
+\skip\footins 39pt plus 4pt minus 12pt
+\def\footnoterule{%
+ \dimen@\skip\footins\divide\dimen@\tw@
+ \kern-\dimen@\hrule width.5in\kern\dimen@
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\floatsep 12pt plus 2pt minus 2pt
+\textfloatsep 20pt plus 2pt minus 4pt
+\intextsep 12pt plus 2pt minus 2pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\dblfloatsep 12pt plus 2pt minus 2pt
+\dbltextfloatsep 20pt plus 2pt minus 4pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\@fptop 0pt plus 1fil
+\@fpsep 8pt plus 2fil
+\@fpbot 0pt plus 1fil
+\@dblfptop 0pt plus 1fil
+\@dblfpsep 8pt plus 2fil
+\@dblfpbot 0pt plus 1fil
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\marginparpush 5pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\parskip 0pt plus 1pt
+\parindent 10pt
+\emergencystretch8\p@
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\partopsep 2pt plus 1pt minus 1pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\leftmargini 25pt
+\leftmarginii 22pt
+\leftmarginiii 18.7pt
+\leftmarginiv 17pt
+\leftmarginv 10pt
+\leftmarginvi 10pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listI{%
+  \leftmargin\leftmargini
+  \parsep 4\p@ plus2\p@ minus\p@
+  \topsep 8\p@ plus2\p@ minus4\p@
+  \itemsep 4\p@ plus2\p@ minus\p@
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\labelsep 4pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listii{%
+  \leftmargin\leftmarginii
+  \labelwidth\leftmarginii
+  \advance\labelwidth-\labelsep
+  \topsep 4\p@ plus2\p@ minus\p@
+  \parsep 2\p@ plus\p@ minus\p@
+  \itemsep \parsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listiii{%
+  \leftmargin\leftmarginiii
+  \labelwidth\leftmarginiii
+  \advance\labelwidth-\labelsep
+  \topsep 2\p@ plus\p@ minus\p@
+  \parsep \z@
+  \partopsep \p@ plus\z@ minus\p@
+  \itemsep \topsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listiv{%
+  \leftmargin\leftmarginiv
+  \labelwidth\leftmarginiv
+  \advance\labelwidth-\labelsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listv{%
+  \leftmargin\leftmarginv
+  \labelwidth\leftmarginv
+  \advance\labelwidth-\labelsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listvi{%
+  \leftmargin\leftmarginvi
+  \labelwidth\leftmarginvi
+  \advance\labelwidth-\labelsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%</10pt>
+%    \end{macrocode}
+%
+% \section{The \classoption{11pt} class option: the \texttt{11pt} module}
+% \changes{4.0b}{1999/06/20}{AO: all code for \protect\classoption{11pt} is in this module.}
+% The file \file{11pt.rtx} is read in by the \classname{revtex4} document class
+% if \cmd\@pointsize\ has the value 11.
+%
+%    \begin{macrocode}
+%<*11pt>
+%    \end{macrocode}
+%
+% \subsection{Defend Against Forseeable Errors}%
+% Protect this file from being read in by anything but \revtex.
+%    \begin{macrocode}
+\ifx\undefined\substyle@ext
+ \def\@tempa{%
+  \endinput
+  \GenericWarning{I must be read in by REVTeX! (Bailing out)}%
+ }%
+ \expandafter\else
+  \def\@tempa{}%
+ \expandafter\fi\@tempa
+ \class@info{RevTeX pointsize 11pt selected}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\normalsize{%
+    \@setfontsize\normalsize\@xipt{13.6}%
+    \abovedisplayskip 11\p@ \@plus3\p@ \@minus6\p@
+    \belowdisplayskip \abovedisplayskip
+    \abovedisplayshortskip  \abovedisplayskip
+    \belowdisplayshortskip \abovedisplayskip
+    \let\@listi\@listI
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\small{%
+   \@setfontsize\small\@xpt\@xiipt
+   \abovedisplayskip 10\p@ \@plus2\p@ \@minus5\p@
+   \abovedisplayshortskip \z@ \@plus3\p@
+   \belowdisplayshortskip 6\p@ \@plus3\p@ \@minus3\p@
+   \def\@listi{\leftmargin\leftmargini
+               \topsep 6\p@ \@plus2\p@ \@minus2\p@
+               \parsep 3\p@ \@plus2\p@ \@minus\p@
+               \itemsep \parsep
+   }%
+   \belowdisplayskip \abovedisplayskip
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\footnotesize{%
+   \@setfontsize\footnotesize\@ixpt{11}%
+   \abovedisplayskip 8\p@ \@plus2\p@ \@minus4\p@
+   \abovedisplayshortskip \z@ \@plus\p@
+   \belowdisplayshortskip 4\p@ \@plus2\p@ \@minus2\p@
+   \def\@listi{\leftmargin\leftmargini
+               \topsep 4\p@ \@plus2\p@ \@minus2\p@
+               \parsep 2\p@ \@plus\p@ \@minus\p@
+               \itemsep \parsep
+   }%
+   \belowdisplayskip \abovedisplayskip
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\scriptsize{%
+  \@setfontsize\scriptsize\@viiipt{9.5}%
+}%
+\def\tiny{%
+  \@setfontsize\tiny\@vipt\@viipt
+}%
+\def\large{%
+  \@setfontsize\large\@xiipt{14}%
+}%
+\def\Large{%
+  \@setfontsize\Large\@xivpt{18}%
+}%
+\def\LARGE{%
+  \@setfontsize\LARGE\@xviipt{22}%
+}%
+\def\huge{%
+    \@setfontsize\huge\@xxpt{25pt}%
+}%
+\def\Huge{%
+  \@setfontsize\Huge\@xxvpt{30pt}%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%</11pt>
+%    \end{macrocode}
+%
+% \section{The \classoption{12pt} class option: the \texttt{12pt} module}
+% \changes{4.0b}{1999/06/20}{AO: all code for \protect\classoption{12pt} is in this module.}
+% The file \file{12pt.rtx} is read in by the \classname{revtex4} document class
+% if \cmd\@pointsize\ has the value 12.
+%
+%    \begin{macrocode}
+%<*12pt>
+%    \end{macrocode}
+%
+% \subsection{Defend Against Forseeable Errors}%
+% Protect this file from being read in by anything but \revtex.
+%    \begin{macrocode}
+\ifx\undefined\substyle@ext
+ \def\@tempa{%
+  \endinput
+  \GenericWarning{I must be read in by REVTeX! (Bailing out)}%
+ }%
+ \expandafter\else
+  \def\@tempa{}%
+ \expandafter\fi\@tempa
+ \class@info{RevTeX pointsize 12pt selected}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\normalsize{%
+  \@setfontsize\normalsize\@xiipt{14pt}%
+  \abovedisplayskip 12\p@ \@plus3\p@ \@minus7\p@
+  \belowdisplayskip \abovedisplayskip
+  \abovedisplayshortskip  \z@ plus3\p@
+  \belowdisplayshortskip  6.5\p@ \@plus3.5\p@ \@minus3\p@
+  \let\@listi\@listI
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+ \def\small{%
+  \@setfontsize\small\@xipt{14.5pt}%
+  \abovedisplayskip 8\p@ \@plus3\p@ \@minus6\p@
+  \belowdisplayskip \abovedisplayskip
+  \abovedisplayshortskip \z@ \@plus3\p@
+  \belowdisplayshortskip 6.5\p@ \@plus3.5\p@ \@minus3\p@
+  \def\@listi{%
+    \leftmargin\leftmargini
+    \topsep 9\p@ \@plus3\p@ \@minus5\p@
+    \parsep 4.5\p@ \@plus2\p@ \@minus\p@
+    \itemsep \parsep
+  }%
+}%
+%    \end{macrocode}
+%
+% Same baselineskip as \cmd\small\ ?
+%    \begin{macrocode}
+ \def\footnotesize{%
+  \@setfontsize\footnotesize\@xpt{14.5pt}%
+  \abovedisplayskip 10\p@ \@plus2\p@ \@minus5\p@
+  \belowdisplayskip \abovedisplayskip
+  \abovedisplayshortskip \z@ \@plus3\p@
+  \belowdisplayshortskip 6\p@ \@plus3\p@ \@minus3\p@
+  \def\@listi{%
+    \leftmargin\leftmargini
+    \topsep 6\p@ \@plus2\p@ \@minus2\p@
+    \parsep 3\p@ \@plus2\p@ \@minus\p@
+    \itemsep \parsep
+  }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\scriptsize{%
+  \@setfontsize\scriptsize\@viiipt{9.5pt}%
+}%
+\def\tiny{%
+  \@setfontsize\tiny\@vipt{7pt}%
+}%
+\def\large{%
+  \@setfontsize\large\@xivpt{18pt}%
+}%
+\def\Large{%
+  \@setfontsize\Large\@xviipt{22pt}%
+}%
+\def\LARGE{%
+  \@setfontsize\LARGE\@xxpt{25pt}%
+}%
+\def\huge{%
+    \@setfontsize\huge\@xxvpt{30pt}%
+}%
+\let\Huge=\huge
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%</12pt>
+%    \end{macrocode}
+%
+% \section{Page parameters}%
+% This code is common to both \classoption{11pt} and \classoption{12pt}.
+%
+%    \begin{macrocode}
+%<*11pt|12pt>
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \twoside@sw{%
+  \oddsidemargin   0pt
+  \evensidemargin  0pt
+  \marginparwidth 60pt
+ }{%
+  \oddsidemargin 0pt
+  \evensidemargin 0pt
+  \marginparwidth 44pt
+ }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\marginparsep 10pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\topmargin -37pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\headheight 12pt
+\headsep 25pt
+%    \end{macrocode}
+%
+% \changes{4.1n}{2010/01/02}{(AO, 571) class file must set \cs{splittopskip}; fine tune \cs{skip}\cs{footins}; \cs{footnoterule} defined in terms of \cs{skip}\cs{footins}}%
+%    \begin{macrocode}
+\topskip 10pt
+\splittopskip\topskip
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\footskip 30pt
+%    \end{macrocode}
+% 
+%    \begin{macrocode}
+\textheight=665.5\p@
+%    \end{macrocode}
+% 
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \tightenlines@sw{%
+  \def\baselinestretch{1}%
+ }{%
+  \def\baselinestretch{1.5}%
+ }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\textwidth 468pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\columnsep 10pt
+\columnseprule 0pt
+%    \end{macrocode}
+%
+% \changes{4.1n}{2010/01/02}{(AO, 571) class file must set \cs{splittopskip}; fine tune \cs{skip}\cs{footins}; \cs{footnoterule} defined in terms of \cs{skip}\cs{footins}}%
+%    \begin{macrocode}
+\footnotesep 1pt
+\skip\footins 25.25pt plus 4pt minus 12pt
+\def\footnoterule{%
+ \dimen@\skip\footins\divide\dimen@\f@ur
+ \kern-\dimen@\hrule width.5in\kern\dimen@
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\floatsep        14pt plus 2pt minus 4pt
+\textfloatsep    20pt plus 2pt minus 4pt
+\intextsep       14pt plus 4pt minus 4pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\dblfloatsep     14pt plus 2pt minus 4pt
+\dbltextfloatsep 20pt plus 2pt minus 4pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\@fptop 0pt plus 1fil
+\@fpsep 10pt plus 2fil
+\@fpbot 0pt plus 1fil
+\@dblfptop 0pt plus 1fil
+\@dblfpsep 10pt plus 2fil%
+\@dblfpbot 0pt plus 1fil
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\marginparpush 7pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\parskip 0pt plus 1pt
+\parindent 15pt
+\emergencystretch8\p@
+\partopsep 3pt plus 2pt minus 2pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\leftmargini   30pt
+\leftmarginii  26pt
+\leftmarginiii 22pt
+\leftmarginiv  20pt
+\leftmarginv   12pt
+\leftmarginvi  12pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listI{\leftmargin\leftmargini \parsep 5\p@ plus2.5\p@ minus\p@
+  \topsep 10\p@ plus4\p@ minus6\p@
+  \itemsep 5\p@ plus2.5\p@ minus\p@
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\labelsep 6pt
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listii{\leftmargin\leftmarginii
+  \labelwidth\leftmarginii\advance\labelwidth-\labelsep
+  \topsep 5\p@ plus2.5\p@ minus\p@
+  \parsep 2.5\p@ plus\p@ minus\p@
+  \itemsep \parsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listiii{\leftmargin\leftmarginiii
+  \labelwidth\leftmarginiii\advance\labelwidth-\labelsep
+  \topsep 2.5\p@ plus\p@ minus\p@
+  \parsep \z@ \partopsep \p@ plus\z@ minus\p@
+  \itemsep \topsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listiv{\leftmargin\leftmarginiv
+  \labelwidth\leftmarginiv\advance\labelwidth-\labelsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listv{\leftmargin\leftmarginv
+  \labelwidth\leftmarginv\advance\labelwidth-\labelsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\@listvi{\leftmargin\leftmarginvi
+  \labelwidth\leftmarginvi\advance\labelwidth-\labelsep
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+%</11pt|12pt>
+%    \end{macrocode}
+%
+% \section{The \classoption{aps} class extension: the \texttt{aps} module}
+% \changes{4.0b}{1999/06/20}{AO: made aps.rtx part of revtex4.dtx}
+% The file \file{aps.rtx} is read in by the \classname{revtex4} document class
+% if \cmd\@society\ has the value \classoption{aps}.
+%
+% Here, code specific to APS journals is separated out from the \revtex\ document class.
+% (Other societies can customize \revtex\ by supplying their own \file{.rtx} file.)
+%
+% This class extension file is a model for a class extension you might write yourself.
+%
+% First, incorporate a \cmd\ProvidesFile\ command with an optional argument giving
+% the version information, e.g.,
+% \begin{verbatim}
+% \ProvidesFile{foo}[2001/09/11 v1.1 Docinfo]%
+% \end{verbatim}
+%
+% Within the society substyle, there are two things we must do as well:
+% define the default journal, 
+%    \begin{verbatim}
+% \def\@journal@default{pra}%
+%    \end{verbatim}
+% And do likewise for the point size:
+%    \begin{verbatim}
+% \def\@pointsize@default{10}%
+%    \end{verbatim}
+%
+% We first define some text entities (amounting to journal abbreviations),
+% then some APS-specific initializations,
+% then code for particular APS journals.
+% In the latter case, the choice is 
+% keyed off the macro \cmd\@journal.
+%
+%    \begin{macrocode}
+%<*aps>
+%    \end{macrocode}
+%
+% \subsection{Defend Against Forseeable Errors}%
+% Protect this file from being read in by anything but \revtex.
+%    \begin{macrocode}
+\ifx\undefined\substyle@ext
+ \def\@tempa{%
+  \endinput
+  \GenericWarning{I must be read in by REVTeX! (Bailing out)}%
+ }%
+ \expandafter\else
+  \def\@tempa{}%
+ \expandafter\fi\@tempa
+ \class@info{RevTeX society APS selected}%
+%    \end{macrocode}
+%
+% Here are the class options relating to the APS:
+%    \begin{macrocode}
+\DeclareOption{pra}{\change@journal{pra}}%
+\DeclareOption{prb}{\change@journal{prb}}%
+\DeclareOption{prc}{\change@journal{prc}}%
+\DeclareOption{prd}{\change@journal{prd}}%
+\DeclareOption{pre}{\change@journal{pre}}%
+\DeclareOption{prl}{\change@journal{prl}}%
+%\changes{4.2b}{2017/11/21}{(MD) Update options for new titles without "Special Topics" and make prper match style of other journal options}
+\DeclareOption{prab}{\change@journal{prab}}%
+\DeclareOption{prper}{\change@journal{prper}}%
+\DeclareOption{rmp}{\change@journal{rmp}}%
+%\changes{4.2b}{2017/11/21}{(MD) Add options for new APS journals and a generic physrev option for future-proofing}
+\DeclareOption{prx}{\change@journal{prx}}%
+\DeclareOption{prapplied}{\change@journal{prapplied}}%
+\DeclareOption{prmaterials}{\change@journal{prmaterials}}%
+\DeclareOption{prfluids}{\change@journal{prfluids}}%
+\DeclareOption{physrev}{\change@journal{physrev}}%
+%    \end{macrocode}
+%
+% \subsection{Abbreviations}%
+% \changes{4.1p}{2010/02/24}{(AO, 584) Per MD, remove trailing space character from each journal abbreviation: it had caused an extraneous space in the .bbl} 
+% The following macros constitute typing shortcuts for
+% certain journal names.
+%    \begin{macrocode}
+\def\adv{AIP Advances}%
+\def\ao{Appl.\ Opt.}%
+\def\ap{Appl.\ Phys.}%
+\def\apl{Appl.\ Phys.\ Lett.}%
+\def\apm{Appl.\ Phys.\ Lett.\ Mater.}%
+\def\apj{Astrophys.\ J.}%
+\def\bell{Bell Syst.\ Tech.\ J.}%
+\def\bmf{Biomicrofluidics}%
+\def\cha{Chaos}%
+\def\jqe{IEEE J.\ Quantum Electron.}%
+\def\assp{IEEE Trans.\ Acoust.\ Speech Signal Process.}%
+\def\aprop{IEEE Trans.\ Antennas Propag.}%
+\def\mtt{IEEE Trans.\ Microwave Theory Tech.}%
+\def\iovs{Invest.\ Ophthalmol.\ Vis.\ Sci.}%
+\def\jcp{J.\ Chem.\ Phys.}%
+\def\jap{J.\ Appl.\ Phys.}%
+\def\jmp{J.\ Math.\ Phys.}%
+\def\jmo{J.\ Mod.\ Opt.}%
+\def\josa{J.\ Opt.\ Soc.\ Am.}%
+\def\josaa{J.\ Opt.\ Soc.\ Am.\ A}%
+\def\josab{J.\ Opt.\ Soc.\ Am.\ B}%
+\def\jpp{J.\ Phys.\ (Paris)}%
+\def\jpr{J.\ Phys.\ Chem.\ Ref.\ Data}%
+\def\ltp{Low.\ Temp.\ Phys.}%
+\def\nat{Nature (London)}%
+\def\oc{Opt.\ Commun.}%
+\def\ol{Opt.\ Lett.}%
+\def\pl{Phys.\ Lett.}%
+\def\pop{Phys.\ Plasmas}%
+\def\pof{Phys.\ Fluids}%
+\def\pra{Phys.\ Rev.\ A}%
+\def\prb{Phys.\ Rev.\ B}%
+\def\prc{Phys.\ Rev.\ C}%
+\def\prd{Phys.\ Rev.\ D}%
+\def\pre{Phys.\ Rev.\ E}%
+\def\prl{Phys.\ Rev.\ Lett.}%
+\def\rmp{Rev.\ Mod.\ Phys.}%
+\def\rsi{Rev.\ Sci.\ Instrum.}%
+\def\rse{J.\ Renewable Sustainable Energy}%
+\def\pspie{Proc.\ Soc.\ Photo-Opt.\ Instrum.\ Eng.}%
+\def\sjqe{Sov.\ J.\ Quantum Electron.}%
+\def\vr{Vision Res.}%
+\def\sd{Structural\ Dynamics}%
+\def\jor{J.\ Rheol.}%
+\def\cp{AIP\ Conference\ Proceedings}%
+%    \end{macrocode}
+%
+% \subsection{APS Setup}%
+% Here we define the default procedures for APS journals.
+% Individual APS journals may override these definitions.
+%
+% \subsubsection{Title block}%
+%
+% The specifics of the title block.
+% Apply to all APS journals; individual journals may override these settings.
+%
+% \begin{macro}{\@fnsymbol}
+% The \LaTeX\ kernel definition of \cmd\@fnsymbol\ is overridden.
+% The definition in \filename{fixltx2e.sty} serves as a guide to the new way to symbol,
+% working in both text- and math modes. 
+%
+% \filename{fixltx2e.sty} duplicates some features of \filename{ltxgrid} and \filename{ltxutil},
+% however, so it may be incompatible with \revtex. 
+% In case it is not loaded, we must provide a meaning for \cmd\TextOrMath,
+% which that package makes robust. 
+% I believe that it is \cmd\@fnsymbol\ itself that ought to be robustified.
+% e\TeX\ further complicates matters; we do not especially accomodate it. 
+%
+% \changes{4.1d}{2009/03/27}{Definition of \cs{	@fnsymbol} follows fixltx2e.sty}
+%
+% Not! \cmd\TextOrMath\ must be made robust in any case (Bug 530). I return things to follow
+% core \LaTeXe\ (\filename{latex.ltx}). 
+% \changes{4.1f}{2009/10/05}{(AO, 530) \cs{@fnsymbol}: Failed to import fixltx2e.sty technology. Return to LaTeX core.}
+%    \begin{macrocode}
+\def\@fnsymbol#1{%
+ \ensuremath{%
+  \ifcase#1\or 
+   *\or
+   \dagger\or
+   \ddagger\or
+   \mathsection\or
+   \mathparagraph\or
+%  \|\or
+   **\or
+   \dagger\dagger\or
+   \ddagger\ddagger\else
+   \mathsection\mathsection\or
+   \mathparagraph\mathparagraph\or
+   ***\or
+   \dagger\dagger\dagger\or
+   \ddagger\ddagger\ddagger\else
+   \mathsection\mathsection\mathsection\or
+   \mathparagraph\mathparagraph\mathparagraph\or
+%
+   \@ctrerr 
+  \fi
+ }%
+}%
+\appdef\document@inithook{%
+ \@ifxundefined\TextOrMath{%
+  \DeclareRobustCommand\TextOrMath{\@ifmmode{\false@sw}{\true@sw}}%
+ }{}%
+}%
+\let\thefootnote@latex\thefootnote
+%    \end{macrocode}
+% \end{macro}
+%
+% We assign the default titlepage style for APS; a journal or document instance 
+% may override by invoking one of the other \cmd\clo@... procedures defined in \revtex.
+%    \begin{macrocode}
+\clo@groupedaddress
+%    \end{macrocode}
+%
+% \begin{macro}{\titlepage}
+%    \begin{macrocode}
+\renewenvironment{titlepage}{%
+  \let\wastwocol@sw\twocolumn@sw
+  \onecolumngrid
+  \newpage
+  \thispagestyle{titlepage}%
+  \c@page\z@
+%    \end{macrocode}
+% A comment: ``article.cls sets this to one not zero?''
+%    \begin{macrocode}
+}{%
+  \wastwocol@sw{\twocolumngrid}{\newpage}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@abstractheading}
+% APS Journals all set the abstract head the same way, with no head.
+% However, if the user has specified the \classoption{preprint} class option,
+% then the abstract will have a head.
+%    \begin{macrocode}
+\def\frontmatter@abstractheading{%
+ \preprintsty@sw{%
+  \begingroup
+   \centering\large
+   \abstractname
+   \par
+  \endgroup
+ }{}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@abstractwidth}
+% All APS journals set the abstract to the same width.
+%    \begin{macrocode}
+\def\frontmatter@abstractwidth{400\p@}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@abstractfont}
+% All APS journals set the abstract body the same way.
+% \changes{4.0c}{1999/11/13}{(AO, 123) add parskip to the abstract.}
+% \changes{4.1e}{2008/06/29}{(AO, 455) be nice to a list within the abstract}
+%    \begin{macrocode}
+\def\frontmatter@abstractfont{%
+ \small
+ \parindent1em\relax
+ \adjust@abstractwidth
+}%
+\def\adjust@abstractwidth{%
+ \dimen@\textwidth\advance\dimen@-\frontmatter@abstractwidth
+ \divide\dimen@\tw@
+ \galley@sw{%
+  \advance\rightskip\tw@\dimen@
+ }{%
+  \advance\leftskip\dimen@
+  \advance\rightskip\dimen@
+ }%
+ \@totalleftmargin\leftskip
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%\changes{4.2b}{2017/11/22}{(MD) Change default to not use a title page - it seems antiquated}
+% All APS journal preprints use separate titlepage and full-width abstract.
+% 
+% In effect, we establish a society default value for \cmd\preprintsty@sw,
+% and for \cmd\titlepage@sw.
+%    \begin{macrocode}
+\@booleanfalse\preprintsty@sw
+\@booleanfalse\titlepage@sw
+%    \end{macrocode}
+%
+% We choose the page style for all APS journals. 
+% The journal may override by inserting its own code in \cmd\setup@hook. 
+% Users wishing to customize their documents will be able to invoke a \cmd\pagestyle\
+% command anywhere in the preamble; it will override the assignments here. 
+%
+% Here is the big switch for APS preprints. Note that \cmd\preprintsty@sw
+% is also consulted in various procedures, but we assume its value does 
+% not change after \cmd\setup@hook\ time. 
+%    \begin{macrocode}
+\appdef\setup@hook{%
+  \preprintsty@sw{%
+   \ps@preprint
+   \def\frontmatter@abstractwidth{\textwidth}%
+   \def\frontmatter@affiliationfont{\it}%
+   \let\section\section@preprintsty
+%    \end{macrocode}
+% The following line of code had been commented out at this point.
+%    \begin{verbatim}
+%  \let\@hangfrom@section\@hangfrom@section@preprintsty
+%    \end{verbatim}
+%    \begin{macrocode}
+   \let\subsection\subsection@preprintsty
+   \let\subsubsection\subsubsection@preprintsty
+  }{%
+   \ps@article
+  }%
+}%
+%    \end{macrocode}
+%
+% \begin{macro}{\frontmatter@authorformat}
+% All APS journals set the author list the same.
+% The leading is 11.5 points, and
+% there is 11.5 points of extra space above the first author line
+% (which amounts to the same thing as 11.5 points extra below the title)
+% for a total of 23 points base-to-base.
+%
+%    \begin{macrocode}
+\def\frontmatter@authorformat{%
+ \skip@\@flushglue
+ \@flushglue\z@ plus.3\hsize\relax
+ \centering
+ \advance\baselineskip\p@
+ \parskip11.5\p@\relax
+ \@flushglue\skip@
+%    \end{macrocode}
+% The following line of code had been commented out at this point.
+%    \begin{verbatim}
+%\preprintsty@sw{}{%
+% \addvspace{0\p@}%
+%}%
+%    \end{verbatim}
+%    \begin{macrocode}
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@above@affilgroup}
+% The default amount of space above affiliation.
+% APS Journals have 24 points b-b above an affiliation group.
+%    \begin{macrocode}
+\def\frontmatter@above@affilgroup{%
+%    \end{macrocode}
+% The following line of code had been commented out at this point.
+%    \begin{verbatim}
+%\preprintsty@sw{}{%
+% \addvspace{11\p@}%
+%}%
+%    \end{verbatim}
+%    \begin{macrocode}
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@above@affiliation}
+% \begin{macro}{\frontmatter@above@affiliation@script}
+% The default amount of space above affiliation.
+% APS Journals have no extra space between author group down to common affiliation.
+%    \begin{macrocode}
+\def\frontmatter@above@affiliation@script{%
+ \skip@\@flushglue
+ \@flushglue\z@ plus.3\hsize\relax
+ \centering
+ \@flushglue\skip@
+ \addvspace{3.5\p@}%
+}%
+\def\frontmatter@above@affiliation{%
+ \preprintsty@sw{}{%
+%    \end{macrocode}
+% The following line of code had been commented out at this point.
+%    \begin{verbatim}
+% \addvspace{12\p@}%
+%    \end{verbatim}
+%    \begin{macrocode}
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@affiliationfont}
+% All APS journals set the affiliation the same.
+%    \begin{macrocode}
+\def\frontmatter@affiliationfont{%
+ \small\it
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@collaboration@above}
+% PRL: 1.5 points extra: 13 points base-to-base above.
+%    \begin{macrocode}
+\def\frontmatter@collaboration@above{%
+ \preprintsty@sw{%
+ }{%
+  \parskip1.5\p@\relax
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@setup}
+% All APS journals set the title page using the same font and size.
+% However, justification varies for the title block elements, so
+% we assert none here.
+%    \begin{macrocode}
+\def\frontmatter@setup{%
+ \normalfont
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@title@above}
+% \begin{macro}{\frontmatter@title@format}
+% \begin{macro}{\frontmatter@title@below}
+% All APS journals set the article title the same.
+%
+% Note: Spacing from title to author is 23 points base-to-base.
+%    \begin{macrocode}
+\def\frontmatter@title@above{\addvspace{6\p@}}%
+\def\frontmatter@title@format{\large\bfseries\centering\parskip\z@skip}%
+\def\frontmatter@title@below{}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@makefnmark}
+% All APS journals share this procedure for setting the titlepage footnote text.
+%    \begin{macrocode}
+\def\@author@parskip{3\p@}%
+\def\frontmatter@makefnmark{%
+ \@textsuperscript{%
+  \normalfont\@thefnmark
+ }%
+}%
+\def\frontmatter@authorbelow{%
+ \addvspace{3\p@}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@RRAP@format}
+% All APS journals use the same format for the ``Received, Revised, etc.'' block on the title page.
+%
+% Change note: 11.5 points b-b from author/affiliation down to date.
+%    \begin{macrocode}
+\def\frontmatter@RRAP@format{%
+  \small
+  \centering
+%    \end{macrocode}
+% The following line of code had been commented out at this point.
+%    \begin{verbatim}
+% \preprintsty@sw{}{\parskip.5ex\relax}%
+%    \end{verbatim}
+%    \begin{macrocode}
+  \everypar{\hbox\bgroup(\@gobble@leavemode@uppercase}%
+  \def\par{\@ifvmode{}{\unskip)\egroup\@@par}}%
+}%
+\def\punct@RRAP{;\egroup\ \hbox\bgroup}%
+\def\@gobble@leavemode@uppercase#1#2{\expandafter\MakeTextUppercase}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@PACS@format}
+% 
+%    \begin{macrocode}
+\def\frontmatter@PACS@format{%
+   \addvspace{11\p@}%
+   \footnotesize
+   \adjust@abstractwidth
+   \parindent\z@
+   \parskip\z@skip
+   \samepage
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@keys@format}
+% 
+%    \begin{macrocode}
+\def\frontmatter@keys@format{%
+   \footnotesize
+   \adjust@abstractwidth
+   \parindent\z@
+   \samepage
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\ps@titlepage}
+% \changes{4.0a}{1998/06/10}{multiple preprint commands}
+% \changes{4.0b}{1999/06/20}{Stack \cs{preprint} args flush right at right margin.}
+% Title page style. Currently empty except for preprint header,
+% which consists of all the \cmd\preprint\ arguments,
+% stacked flush right at the right margin.
+% \changes{4.0c}{1999/11/13}{Insert procedure \cs{checkindate}}
+%    \begin{macrocode}
+\def\ps@titlepage{%
+  \def\@oddhead{%
+   \hfill
+   \preprint@sw{%
+    \expandafter\produce@preprints\expandafter{\@preprint}%
+   }{}%
+  }%
+  \let\@evenhead\@oddhead
+  \def\@oddfoot{%
+   \hb@xt@\z@{\byrevtex\hss}%
+   \hfil
+   \preprintsty@sw{\thepage}{}%
+   \quad\checkindate
+   \hfil
+  }%
+  \let\@evenfoot\@oddfoot
+}%
+\def\byrevtex{\byrevtex@sw{Typeset by REV\TeX}{}}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\produce@preprints}
+% \changes{4.0c}{1999/11/13}{(AO, 115) If three or more preprints specified, set on single line, with commas.}
+%    \begin{macrocode}
+\def\produce@preprints#1{%
+ \vtop to \z@{%
+  \def\baselinestretch{1}%
+  \small
+  \let\preprint\preprint@count
+  \count@\z@
+  #1%
+  \@ifnum{\count@>\tw@}{%
+   \hbox{%
+    \let\preprint\preprint@hlist
+    #1%
+    \setbox\z@\lastbox
+   }%
+  }{%
+   \let\preprint\preprint@cr
+   \halign{\hfil##\cr#1\crcr}%
+   \par
+   \vss
+  }%
+ }%
+}%
+\def\preprint@cr#1{#1\cr}%
+\def\preprint@count#1{\advance\count@\@ne}%
+\def\preprint@hlist#1{#1\hbox{, }}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Stacked Heads}%
+% All APS journals put a period (.), followed by quad space, after the section number.
+% Also, no hanging section number.
+%    \begin{macrocode}
+\def\@seccntformat#1{\csname the#1\endcsname.\quad}%
+\def\@hang@from#1#2#3{#1#2#3}%
+%    \end{macrocode}
+%
+% Note that in the following, we wish to set the section head uppercase, so we use
+% David Carlisle's \cmd\MakeTextUppercase. However, because this procedure effectively 
+% parses its argument (looking for things to \emph{not} translate), it has to be invoked
+% in such a way that the argument of the \cmd\section\ command is passed to it as its
+% own argument. 
+%
+% To accomplish this, we use the \cmd\@hangfrom@\ hook, which was developed for this 
+% purpose.
+%
+%    \begin{macrocode}
+\def\section{%
+  \@startsection
+    {section}%
+    {1}%
+    {\z@}%
+    {0.8cm \@plus1ex \@minus .2ex}%
+    {0.5cm}%
+    {%
+      \normalfont\small\bfseries
+      \centering
+    }%
+}%
+\def\@hangfrom@section#1#2#3{\@hangfrom{#1#2}\MakeTextUppercase{#3}}%
+\def\@hangfroms@section#1#2{#1\MakeTextUppercase{#2}}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\subsection{%
+  \@startsection
+    {subsection}%
+    {2}%
+    {\z@}%
+    {.8cm \@plus1ex \@minus .2ex}%
+    {.5cm}%
+    {%
+     \normalfont\small\bfseries
+     \centering
+    }%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\subsubsection{%
+  \@startsection
+    {subsubsection}%
+    {3}%
+    {\z@}%
+    {.8cm \@plus1ex \@minus .2ex}%
+    {.5cm}%
+    {%
+     \normalfont\small\itshape
+     \centering
+    }%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{Runin Heads}%
+%    \begin{macrocode}
+\def\paragraph{%
+  \@startsection
+    {paragraph}%
+    {4}%
+    {\parindent}%
+    {\z@}%
+    {-1em}%
+    {\normalfont\normalsize\itshape}%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\subparagraph{%
+  \@startsection
+    {subparagraph}%
+    {5}%
+    {\parindent}%
+    {3.25ex \@plus1ex \@minus .2ex}%
+    {-1em}%
+    {\normalfont\normalsize\bfseries}%
+}%
+%    \end{macrocode}
+%
+%
+%
+% \begin{macro}{\section@preprintsty}
+% \begin{macro}{\subsection@preprintsty}
+% \begin{macro}{\subsubsection@preprintsty}
+% Here are the formatting procedures specific to the preprint style;
+% the only difference is that the heads are flush left instead of centered.
+%
+%    \begin{macrocode}
+\def\section@preprintsty{%
+  \@startsection
+    {section}%
+    {1}%
+    {\z@}%
+    {0.8cm \@plus1ex \@minus .2ex}%
+    {0.5cm}%
+    {%
+      \normalfont\small\bfseries
+%     \centering
+    }%
+}%
+%\def\@hangfrom@section@preprintsty#1#2#3{\@hangfrom{#1#2}\MakeTextUppercase{#3}}%
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\subsection@preprintsty{%
+  \@startsection
+    {subsection}%
+    {2}%
+    {\z@}%
+    {.8cm \@plus1ex \@minus .2ex}%
+    {.5cm}%
+    {%
+     \normalfont\small\bfseries
+%    \centering
+    }%
+}%
+%    \end{macrocode}
+%    \begin{macrocode}
+\def\subsubsection@preprintsty{%
+  \@startsection
+    {subsubsection}%
+    {3}%
+    {\z@}%
+    {.8cm \@plus1ex \@minus .2ex}%
+    {.5cm}%
+    {%
+     \normalfont\small\itshape
+%    \centering
+    }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% By default, APS journals set titlepage notes as footnotes.
+%    \begin{verbatim}
+\let\frontmatter@footnote@produce\frontmatter@footnote@produce@footnote
+%    \end{verbatim}
+%
+% \subsubsection{Table of Contents}%
+% The toc will itself make an entry in the toc, 
+% but we temporarily turn off toc formatting for the duration.
+% \changes{4.1a}{2008/01/19}{(AO, 461) Change the csname revtex uses from @dotsep to ltxu@dotsep. The former is understood in mu. (What we wanted was a dimension.)}%
+%    \begin{macrocode}
+\def\@pnumwidth{1.55em}%
+\def\@tocrmarg {2.55em}%
+\def\@dotsep{2}%
+\def\ltxu@dotsep{4.5pt}%
+\setcounter{tocdepth}{3}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\tableofcontents{%
+ \addtocontents{toc}{\string\tocdepth@munge}%
+ \print@toc{toc}%
+ \addtocontents{toc}{\string\tocdepth@restore}%
+}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\tocdepth@munge{%
+  \let\l@section@saved\l@section
+  \let\l@section\@gobble@tw@
+}%
+\def\@gobble@tw@#1#2{}%
+%    \end{macrocode}
+%
+%    \begin{macrocode}
+\def\tocdepth@restore{%
+  \let\l@section\l@section@saved
+}%
+%    \end{macrocode}
+%
+% The following definition of \cmd\l@part\ is a variant on
+% the definition of \cmd\l@@sections\ in \file{ltxutil.dtx}.
+%    \begin{macrocode}
+\def\l@part#1#2{\addpenalty{\@secpenalty}%
+ \begingroup
+  \set@tocdim@pagenum\@tempboxa{#2}%
+% \@tempdima 3em %
+  \parindent \z@
+  \rightskip\tocleft@pagenum plus 1fil\relax
+  \skip@\parfillskip\parfillskip\z@
+  \addvspace{2.25em plus\p@}%
+  \large \bf %
+  \leavevmode\ignorespaces#1\unskip\nobreak\hskip\skip@
+  \hb@xt@\rightskip{\hfil\unhbox\@tempboxa}\hskip-\rightskip\hskip\z@skip
+  \par
+  \nobreak %
+ \endgroup
+}%
+%    \end{macrocode}
+%
+% \begin{macro}{\l@section}
+% Determine which TOC elements are automatically indented.
+%
+% We set the TOC to the standard of RMP. 
+% If APS has its own specification, we will code it, and RMP must override.
+%    \begin{macrocode}
+\def\tocleft@{\z@}%
+\def\tocdim@min{5\p@}%
+\def\l@section{%
+ \l@@sections{}{section}% Implicit #3#4
+}%
+\def\l@f@section{%
+ \addpenalty{\@secpenalty}%
+ \addvspace{1.0em plus\p@}%
+ %\bf
+}%
+\def\l@subsection{%
+ \l@@sections{section}{subsection}% Implicit #3#4
+}%
+\def\l@subsubsection{%
+ \l@@sections{subsection}{subsubsection}% Implicit #3#4
+}%
+\def\l@paragraph#1#2{}%
+\def\l@subparagraph#1#2{}%
+%    \end{macrocode}
+% \end{macro}
+%
+% Activate the auto TOC processing.
+%    \begin{macrocode}
+\let\toc@pre\toc@pre@auto
+\let\toc@post\toc@post@auto
+%    \end{macrocode}
+%
+% \subsubsection{Default column bottom}%
+% All APS journal styles have flush bottoms.
+%\changes{4.1n}{2009/11/30}{(AO, 566) restore 4.0 behavior: flush column bottoms}
+%    \begin{macrocode}
+\@booleanfalse\raggedcolumn@sw
+%    \end{macrocode}
+%
+%
+% \subsubsection{Table alignment style}%
+%
+% \begin{macro}{\tableft@skip@float}
+% \begin{macro}{\tabmid@skip@float}
+% \begin{macro}{\tabright@skip@float}
+% \begin{macro}{\array@row@pre@float}
+% \begin{macro}{\array@row@pst@float}
+% All APS publications have the same table specification:
+% Scotch rules above and below, centered in column.
+%    \begin{macrocode}
+\def\tableft@skip@float{\z@ plus\hsize}%
+\def\tabmid@skip@float{\@flushglue}%
+\def\tabright@skip@float{\z@ plus\hsize}%
+\def\array@row@pre@float{\hline\hline\noalign{\vskip\doublerulesep}}%
+\def\array@row@pst@float{\noalign{\vskip\doublerulesep}\hline\hline}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsubsection{Footnote formatting}%
+% \changes{4.1n}{2010/01/02}{(AO, 572) \cs{@makefntext} and \cs{frontmatter@makefntext} must be defined harmoniously}%
+% We customize the formatting of footnotes for all APS journals.
+% \begin{macro}{\@makefntext}
+%    \begin{macrocode}
+\long\def\@makefntext#1{%
+ \def\baselinestretch{1}%
+ \leftskip1em%
+ \parindent1em%
+ \noindent
+ \nobreak\hskip-\leftskip
+ \hb@xt@\leftskip{%
+  \hss\@makefnmark\ %
+ }%
+ #1%
+ \par
+}%
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\frontmatter@makefntext}
+% We ensure that frontmatter footnotes format similarly to body footnotes. 
+% But we provide our own hypertext anchor, otherwise not provided.
+% \changes{4.1n}{2010/01/02}{(AO, 572) Independent footnote counter for title block. Abstract footnote counter shared with body.}%
+%    \begin{macrocode}
+\long\def\frontmatter@makefntext#1{%
+ \def\baselinestretch{1}%
+ \leftskip1em%
+ \parindent1em%
+ \noindent
+ \nobreak\hskip-\leftskip
+ \Hy@raisedlink{\hyper@anchorstart{frontmatter.\expandafter\the\csname c@\@mpfn\endcsname}\hyper@anchorend}%
+ \hb@xt@\leftskip{%
+  \hss\@makefnmark\ %
+ }%
+ #1%
+ \par
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsubsection{Appendix}%
+% \begin{macro}{\appendix}
+% \begin{macro}{\@hangfrom@appendix}
+% \begin{macro}{\@hangfroms@appendix}
+% \begin{macro}{\@appendixcntformat}
+% \changes{4.0c}{1999/11/13}{(AO, 129) section* within appendix was producing appendixname}
+%    \begin{macrocode}
+\prepdef\appendix{%
+ \par
+ \let\@hangfrom@section\@hangfrom@appendix
+%\let\@hangfroms@section\@hangfroms@appendix
+ \let\@sectioncntformat\@appendixcntformat
+}%
+\def\@hangfrom@appendix#1#2#3{%
+ #1%
+ \@if@empty{#2}{%
+  #3%
+ }{%
+  #2\@if@empty{#3}{}{:\ #3}%
+ }%
+}%
+\def\@hangfroms@appendix#1#2{%
+ #1#2%
+}%
+\def\@appendixcntformat#1{\appendixname\ \csname the#1\endcsname}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Bibliography}%
+% \changes{4.1n}{2010/01/04}{(AO, 576) In .bst files, remove support for the annote field}%
+%
+% Customize \revtex\ for the journal substyle;
+% this task requires three components:
+% the \BibTeX\ \file{apsrev.bst} and \file{apsrmp.bst} style files, and
+% customizations of the \env{thebibliography} environment.
+%
+% \begin{macro}{\@bibstyle}
+% Define the argument of the \cmd\bibliographystyle\ command
+% (if the document does not do so).
+% The user must have installed a \file{.bst} file of the corresponding name.
+% This file will then be used by \BibTeX\ when compiling the document's \file{.bbl} file.
+%
+%  To generate \file{apsrev.bst}, use \classname{custom-bib} version 4.21 or later.
+%  Run the \file{.bst} generator, \file{makebst.tex}, and
+%  accept all defaults, with the following exceptions:
+%
+% \def\QandA#1#2#3{\item#1: \textbf{#2}: \texttt{#3}---}%
+% \def\CandE#1{\item\relax\texttt{#1}---}%
+% \begin{enumerate}
+% \QandA{LANGUAGE FIELD}{l}{lang}Use language field to switch hyphenation patterns for title
+% \QandA{PRESENTATIONS}{b}{pres,pres-bf}Presentation, speaker bold face 
+% \QandA{ORDERING OF REFERENCES}{c}{seq-no}Citation order (unsorted, like unsrt.bst)
+% \QandA{ORDER ON VON PART}{x}{vonx}Sort without von part (de la Maire after Mahone)
+% \QandA{AUTHOR NAMES}{i}{nm-init,ed-au}Initials + surname (J. F. Smith)
+% \QandA{POSITION OF JUNIOR}{*}{jnrlst}Junior comes last as Smith, John, Jr.
+% \QandA{TYPEFACE FOR AUTHORS IN LIST OF REFERENCES}{u}{nmft,nmft-def}User defined author font (\cmd\bibnamefont)
+% \QandA{FONT FOR FIRST NAMES}{u}{fnm-def}First names in user defined font (\cmd\bibfnamefont)
+% \QandA{EDITOR NAMES IN INCOLLECTION ETC}{a}{nmfted}Editors incollection like authors font
+% \QandA{FONT FOR `AND' IN LIST}{r}{nmand-rm}`And' in normal font (JONES and JAMES)
+% \QandA{FONT OF CITATION LABELS IN TEXT}{u}{lab,lab-def}User defined citation font (\cmd\citenamefont)
+% \QandA{FONT FOR `AND' IN CITATIONS}{r}{and-rm}Cited `and' in normal font 
+% \QandA{DATE FORMAT}{*}{yr-par}Date in parentheses as (May 1993)
+% \QandA{DATE EMPTY}{-}{date-nil-x}If date is empty, then do not produce the surrounding punctuation (parens, brackets, colon, comma)
+% \QandA{TITLE OF ARTICLE}{d}{tit-qq}Title and punctuation in double quotes (``Title,'' ..)
+% \QandA{INPROCEEDINGS CHAPTER AND PAGES, LIKE INBOOK}{-}{inproceedings-chapter}produce pages after chapter, just as in InBook
+% \QandA{TITLE PRESENT IN ARTICLE, INCOLLECTION, AND INPROCEEDINGS}{x}{jtit-x}Title is ignored
+% \QandA{INPROCEEDINGS CHAPTER AND PAGES, LIKE INBOOK}{y}{inproceedings-chapter}produce pages after chapter, just as in InBook
+% \QandA{ARTICLE BOOKTITLE PRESENT}{}{article-booktitle}format booktitle 
+% \QandA{ARTICLE SERIES PRESENT}{}{article-series}article can has series
+% \QandA{JOURNAL NAME FONT}{r}{jttl-rm}Journal name normal font
+% \QandA{JOURNAL NAME WITH ADDRESS}{y}{journal-address}Include address field (in parentheses) along with journal name
+% \QandA{BOOK TITLE FIELDS}{y}{book-bt}Field `booktitle', or if absent field `title', is book title 
+% \QandA{THESIS TITLE OPTIONAL}{}{thesis-title-o}Title is optional: no warning issued if empty
+% \QandA{TECHNICAL REPORT TITLE}{b}{trtit-b}Tech. report title like books 
+% \QandA{TECHNICAL REPORT INSTITUTION}{}{techreport-institution-par}format tech report institution like book publisher
+% \QandA{JOURNAL VOLUME}{b}{vol-bf}Volume bold as {\bf vol}(num)
+% \QandA{JOURNAL VOL AND NUMBER}{x}{vnum-x}Journal vol, without number as 34
+% \QandA{VOLUME PUNCTUATION}{c}{volp-com}Volume with comma as vol(num), ppp
+% \QandA{PAGE NUMBERS}{f}{jpg-1}Only start page number 
+% \QandA{BOOK EDITOR W/O AUTHOR}{}{book-editor-booktitle}Book permits empty author, produces title before editor in this case
+% \QandA{INBOOK PERMITS TITLE, BOOKTITLE, AUTHOR, EDITOR}{a}{inbook-editor-booktitle}Allow using both title/booktitle, both author/editor
+% \QandA{CONFERENCE ADDRESS FOR BOOK, INBOOK, INCOLLECTION, INPROCEEDINGS, PROCEEDINGS}{a}{bookaddress}Italic booktitle followed by bookaddress in roman
+% \QandA{NUMBER AND SERIES FOR BOOK, INBOOK, INCOLLECTION, INPROCEEDINGS, PROCEEDINGS}{*}{num-xser}Allows number without series and suppresses word "number"
+% \QandA{WORD NUMBER CAPITALIZED FOR NUMBER AND SERIES}{c}{number-cap}Capitalize word `number' as: "Number 123"
+% \QandA{WORD CHAPTER CAPITALIZED}{c}{chapter-cap}Capitalize word `chapter' as: `Chapter 42'
+% \QandA{COMBINING NUMBER AND SERIES}{x}{series-number}Series number as: `Springer Lecture Notes No. 125'
+% \QandA{POSITION OF NUMBER AND SERIES}{b}{numser-booktitle}After book title and conference address, and before editors 
+% \QandA{VOLUME AND SERIES FOR BOOKS/COLLECTIONS}{s}{ser-vol}Series, vol. 23
+% \QandA{VOLUME AND SERIES FORMATTING}{y}{ser-rm}format series roman , even when used with volume
+% \QandA{WORD VOLUME CAPITALIZED FOR VOLUME AND SERIES}{y}{volume-cap}Capitalize word `volume', as: `Volume 7 in Lecture Series'
+% \QandA{POSITION OF VOLUME AND SERIES FOR INCOLLECTION, INBOOK, AND INPROCEEDINGS}{e}{ser-ed}Series and volume after booktitle and before editors
+% \QandA{JOURNAL NAME PUNCTUATION}{x}{jnm-x}Space after journal name
+% \QandA{PAGES IN BOOK}{*}{pg-bk,book-chapter-pages}As chapter and page: chapter 42, page 345
+% \QandA{PUBLISHER IN PARENTHESES}{d}{pub-date}Publisher with address and date in parentheses (Oxford, 1994)
+% \QandA{EMPTY PUBLISHER PARENTHESES}{y}{ay-empty-pub-parens-x}eliminate parentheses altogether if nothing inside
+% \QandA{PUBLISHER POSITION}{}{pre-pub}Publisher before volume, chapter, pages 
+% \QandA{}{}{pre-edn}Edition before publisher
+% \QandA{}{p}{pre-pub,pre-edn}Edition, publisher, volume, chapter, pages
+% \QandA{ISBN NUMBER}{*}{isbn}Include ISBN for books, booklets, etc.
+% \QandA{ISSN NUMBER}{*}{issn}Include ISSN for periodicals
+% \QandA{DOI NUMBER}{a}{doi-link,doi}Doi forms a link to the publication, anchored to the volume or title
+% \QandA{EDITOR IN COLLECTIONS}{b}{edby}In booktitle, edited by ..  (where .. is names)
+% \QandA{PUNCTUATION BETWEEN SECTIONS (BLOCKS)}{c}{blk-com}Comma between blocks 
+% \QandA{FINAL PUNCTUATION}{c}{fin-endbibitem}Command at end instead of period 
+% \QandA{ABBREVIATE WORD `PAGES'}{a}{pp}`Page' abbreviated as p. or pp.
+% \QandA{ABBREVIATE WORD `EDITORS'}{a}{ed}`Editor' abbreviated as ed. or eds.
+% \QandA{OTHER ABBREVIATIONS}{a}{abr}Abbreviations of such words
+% \QandA{ABBREVIATION FOR `EDITION'}{a}{ednx}`Edition' abbreviated as `ed' 
+% \QandA{EDITION NUMBERS}{n}{ord}Numerical editions as 1st, 2nd, 3rd, etc
+% \QandA{STORED JOURNAL NAMES}{a}{jabr}Abbreviated journal names 
+% \QandA{FONT OF `ET AL'}{i}{etal-it}Italic et al 
+% \QandA{ADDITIONAL REVTeX DATA FIELDS}{r}{revdata,eprint,url,url-blk,translation}Include REVTeX data fields collaboration, eid, eprint, archive, url, translation
+% \QandA{SLACcitation FIELD}{}{SLACcitation}Produce SLACcitation field
+% \QandA{NUMPAGES DATA FIELD}{*}{numpages-x}Do not include numpages field 
+% \QandA{URL ADDRESS}{*}{url,url-prefix-x}URL without prefix (default: `URL ')
+% \QandA{REFERENCE COMPONENT TAGS}{b}{bibinfo}Reference component tags like \cmd\bibinfo in the content of \cmd\bibitem
+% \QandA{ELEMENT TAGS}{b}{bibfield}Element tags like \cmd\bibfield in the content of \cmd\bibitem
+% \QandA{COMPATIBILITY WITH PLAIN TEX}{*}{nfss}Use LaTeX commands which may not work with Plain TeX
+% \end{enumerate}
+%
+% A file \file{apsrev.dbj} file equivalent to the following should result:
+% \begin{verbatim}
+%\input docstrip
+%\preamble
+%----------------------------------------
+%*** REVTeX-compatible Phys Rev 2010-02-12 ***
+%\endpreamble
+%\postamble
+%End of customized bst file
+%\endpostamble
+%\keepsilent
+%\askforoverwritefalse
+%\def\MBopts{\from{merlin.mbs}{%
+%  head,\MBopta}
+%\from{physjour.mbs}{\MBopta}
+%\from{geojour.mbs}{\MBopta}
+%\from{photjour.mbs}{\MBopta}
+%\from{merlin.mbs}{tail,\MBopta}}
+%\def\MBopta{%
+%  ay,%: Author-year with some non-standard interface
+%  nat,%: Natbib for use with natbib v5.3 or later
+%  lang,%: Use language field to switch hyphenation patterns for title
+%  pres,pres-bf,%: Presentation, speaker bold face 
+%  seq-no,%: Citation order (unsorted, only meaningful for numericals)
+%  vonx,%: Sort without von part (de la Maire after Mahone)
+%  nm-init,ed-au,%: Initials + surname (J. F. Smith)
+%  jnrlst,%: Junior comes last as Smith, John, Jr.
+%  nmft,nmft-def,%: User defined author font (\bibnamefont)
+%  fnm-def,%: First names in user defined font (\bibfnamefont)
+%  nmfted,%: Editors incollection like authors font
+%  nmand-rm,%: `And' in normal font (JONES and JAMES)
+%  lab,lab-def,%: User defined citation font (\citenamefont)
+%  and-rm,%: Cited `and' in normal font 
+%  keyxyr,%: Year blank when KEY replaces missing author (for natbib 7.0)
+%  blkyear,%: Missing date left blank 
+%  yr-par,%: Year in parentheses as (1993)
+%  dtrev,%: Date as year month 
+%  date-nil-x,%: If date is empty, then do not produce the surrounding punctuation (parens, brackets, colon, comma)
+%  tit-qq,%: Title and punctuation in double quotes (``Title,'' ..)
+%  inproceedings-chapter,%: produce pages after chapter, just as in InBook
+%  jtit-x,%: Title is ignored
+%  inproceedings-chapter,%: produce pages after chapter just as in InBook
+%  article-booktitle,%: format booktitle 
+%  article-series,%: article can has series
+%  jttl-rm,%: Journal name normal font
+%  journal-address,%: Include address field (in parentheses) along with journal name
+%  book-bt,%: Field `booktitle', or if absent field `title', is book title 
+%  thesis-title-o,%: Title is optional: no warning issued if empty
+%  trtit-b,%: Tech. report title like books 
+%  techreport-institution-par,%: format tech report institution like book publisher
+%  vol-bf,%: Volume bold as {\bf vol}(num)
+%  vnum-x,%: Journal vol, without number as 34
+%  volp-com,%: Volume with comma as vol(num), ppp
+%  jpg-1,%: Only start page number 
+%  book-editor-booktitle,%: Book permits empty author, produces title before editor in this case
+%  inbook-editor-booktitle,%: Allow using both title/booktitle, both author/editor
+%  bookaddress,%: Italic booktitle followed by bookaddress in roman
+%  num-xser,%: Allows number without series and suppresses word "number"
+%  number-cap,%: Capitalize word `number' as: "Number 123"
+%  chapter-cap,%: Capitalize word `chapter' as: `Chapter 42'
+%  series-number,%: Series number as: `Springer Lecture Notes No. 125'
+%  numser-booktitle,%: After book title and conference address, and before editors 
+%  ser-vol,%: Series, vol. 23
+%  ser-rm,%: format series roman , even when used with volume
+%  volume-cap,%: Capitalize word `volume', as: `Volume 7 in Lecture Series'
+%  ser-ed,%: Series and volume after booktitle and before editors
+%  jnm-x,%: Space after journal name
+%  pg-bk,book-chapter-pages,%: As chapter and page: chapter 42, page 345
+%  pub-date,%: Publisher with address and date in parentheses (Oxford, 1994)
+%  ay-empty-pub-parens-x,%: eliminate parentheses altogether if nothing inside
+%  pre-pub,pre-edn,%: Edition, publisher, volume, chapter, pages
+%  isbn,%: Include ISBN for books, booklets, etc.
+%  issn,%: Include ISSN for periodicals
+%  doi-link,doi,%: Doi forms a link to the publication, anchored to the volume or title
+%  edby,%: In booktitle, edited by ..  (where .. is names)
+%  blk-com,%: Comma between blocks 
+%  fin-endbibitem,%: Command at end instead of period 
+%  pp,%: `Page' abbreviated as p. or pp.
+%  ed,%: `Editor' abbreviated as ed. or eds.
+%  abr,%: Abbreviations of such words
+%  ednx,%: `Edition' abbreviated as `ed' 
+%  ord,%: Numerical editions as 1st, 2nd, 3rd, etc
+%  jabr,%: Abbreviated journal names 
+%  etal-it,%: Italic et al 
+%  revdata,eprint,url,url-blk,translation,%: Include REVTeX data fields collaboration, eid, eprint, archive, url, translation
+%  SLACcitation,%: Produce SLACcitation field
+%  numpages-x,%: Do not include numpages field 
+%  url,url-prefix-x,%: URL without prefix (default: `URL ')
+%  bibinfo,%: Reference component tags like \bibinfo in the content of \bibitem
+%  bibfield,%: Element tags like \bibfield in the content of \bibitem
+%  nfss,%: Use LaTeX commands which may not work with Plain TeX
+%,{%
+%  }}
+%\generate{\file{apsrev4-2.bst}{\MBopts}}
+%\endbatchfile
+% \end{verbatim}
+%
+% \subsubsection{Comparing apsrev.bst and apsrmp.bst}\label{sec:CompRevRmp}
+% These two bibliographic styles differ as follows:
+% \file{apsrev.dbj} has the following guard codes, which \file{apsrmp.dbj} does not:
+% \begin{itemize}
+% \CandE{seq-no}%
+%    Citation order (unsorted, like unsrt.bst)
+% \CandE{nm-init,ed-au}%
+%    Initials + surname (J. F. Smith)
+% \CandE{blkyear}%
+%    Missing date left blank 
+% \CandE{date-nil-x}%
+%    If date is empty, then do not produce the surrounding punctuation (parens, brackets, colon, comma)
+% \CandE{inproceedings-chapter}%
+%    produce pages after chapter, just as in InBook
+% \CandE{techreport-institution-par}%
+%    format tech report institution like book publisher
+% \CandE{vnum-x}%
+%    Journal vol, without number as `34'
+% \CandE{pub-date}%
+%    Publisher with address and date in parentheses (Oxford, 1994)
+% \CandE{pre-pub}%
+%    Edition, publisher, volume, chapter, pages. Note that both use guard code pre-edn.
+% \end{itemize}
+%
+% \file{apsrmp.dbj} has the following guard codes, which \file{apsrev.dbj} does not:
+% \begin{itemize}
+% \CandE{nm-rev1}%
+%    Only first name reversed, initials (AGU style: Smith, J. F., H. K. Jones)
+% \CandE{dt-beg}%
+%    Date after authors 
+% \CandE{vnum-sp}%
+%    Journal vol (num) as `34 (2)'
+% \CandE{pp-last}%
+%    Pages at end, but before any notes
+% \CandE{pub-par}%
+%    Publisher in parentheses
+% \CandE{school-par}%
+%    School/address in parens: `(school, address)' 
+% \CandE{bkedcap}%
+%    `Name Editor,' as above, editor upper case
+% \CandE{and-com}%
+%    Comma even with 2 authors as `Tom, and Harry'
+%    
+% \end{itemize}
+%
+% We ensure that the journal substyle has the first word
+% in the matter by installing the (default) APS code 
+% later on (see Section~\ref{sec:aps-defaults}).
+% \end{macro}
+%
+% \begin{macro}{\authoryear@sw}
+% \changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+% Numerical citations: default value of \cmd\authoryear@sw\ is false.
+%    \begin{macrocode}
+\@booleanfalse\authoryear@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bibpunct}
+% The following commands effectively establish the style in which \cmd\cite\ commands are
+% formatted.
+% You can think of them as the second needed component for the bibliography.
+% 
+% Set up for APS numerical citations (once the packages are loaded). 
+% The journal substyle can override these choices.
+%
+% Note that, prior to \classname{natbib} version 8.21, changing \cmd\NAT@sort\ at this late hour would not be totally effective;
+% you would have to give \classname{natbib} the relevant options at load time.
+% From version 8.21 on, \cmd\NAT@sort\ and \cmd\NAT@cmprs\ are not bound at all. 
+% \changes{4.1a}{2008/01/19}{For natbib versions before 8.21, \cs{NAT@sort} was consulted only as natbib was being read in. Now it is fully dynamic.}
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \bibpunct{[}{]}{,}{n}{}{,}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\pre@bibdata}
+% 
+% Set up to write endnotes to a .bib file; its data will be incorporated into the bibliography.
+%    \begin{macrocode}
+ \def\pre@bibdata{\jobname\bibdata@app}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bibsection}
+% We define the sectioning command to use when starting the bibliography.
+%
+% \changes{4.0rc1}{2001/06/18}{grid changes with push and pop}
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \def\bibsection{%
+  \par
+  \onecolumngrid@push
+  \begingroup
+   \baselineskip26\p@
+   \bib@device{\textwidth}{245.5\p@}%
+  \endgroup
+  \nobreak\@nobreaktrue
+  \addvspace{19\p@}%
+  \par
+  \onecolumngrid@pop
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bib@device}
+% \begin{macro}{\bibpreamble}
+% \begin{macro}{\bibsep}
+% \begin{macro}{\newblock}
+% We define the sectioning command to use when starting the bibliography.
+%    \begin{macrocode}
+\def\bib@device#1#2{%
+ \hb@xt@\z@{%
+  \hb@xt@#1{%
+   \hfil
+   \phantomsection
+   \addcontentsline {toc}{section}{\protect\numberline{}\refname}%
+%  \hyper@anchorstart {\@currentHref }%
+   \hb@xt@#2{%
+    \skip@\z@\@plus-1fil\relax
+                           \leaders\hrule height.25 \p@ depth.25 \p@ \hskip\z@\@plus1fil
+    \hskip\skip@
+    \hskip\z@\@plus0.125fil\leaders\hrule height.375\p@ depth.375\p@ \hskip\z@\@plus0.75fil \hskip\z@\@plus0.125fil
+    \hskip\skip@
+    \hskip\z@\@plus0.25 fil\leaders\hrule height.5  \p@ depth.5  \p@ \hskip\z@\@plus0.5 fil \hskip\z@\@plus0.25 fil
+    \hskip\skip@
+    \hskip\z@\@plus0.375fil\leaders\hrule height.625\p@ depth.625\p@ \hskip\z@\@plus0.25fil \hskip\z@\@plus0.375fil
+ %  \hskip\skip@
+ %  \hfil
+   }%
+%  \hyper@anchorend
+   \hfil
+  }%
+  \hss
+ }%
+}%
+\appdef\setup@hook{%
+ \let\bibpreamble\@empty
+ \bibsep\z@\relax
+ \def\newblock{\ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\bibfont}
+% We define the font switch that applies to the body of the bibliography.
+%
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \def\bibfont{%
+  \small
+  \@clubpenalty\clubpenalty
+ }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+%
+% \subsubsection{Index}%
+% FIXME: the following call to \cmd\twocolumn\ appears wrong if we were in two-column grid.
+% \changes{4.0c}{1999/11/13}{grid changes with ltxgrid}
+% \changes{4.0rc1}{2001/06/18}{grid changes with push and pop}
+%    \begin{macrocode}
+\newenvironment{theindex}{%
+ \columnseprule \z@
+ \columnsep 35\p@
+ \c@secnumdepth-\maxdimen
+ \onecolumngrid@push
+ \section{\indexname}%
+ \thispagestyle{plain}%
+ \parindent\z@
+ \parskip\z@ plus.3\p@\relax
+ \let\item\@idxitem
+ \onecolumngrid@pop
+}{%
+%\onecolumngrid@pop
+}%
+%
+\def\@idxitem{\par\hangindent 40\p@}%
+%
+\def\subitem{\par\hangindent 40\p@ \hspace*{20\p@}}%
+%
+\def\subsubitem{\par\hangindent 40\p@ \hspace*{30\p@}}%
+%
+\def\indexspace{\par \vskip 10\p@ plus5\p@ minus3\p@\relax}%
+%    \end{macrocode}
+%
+%
+% \subsection{Journal- and Pointsize-Specific Code}%
+%
+% After this substyle is read in, we will execute the code specific to the selected 
+% journal: execute the society/journal \file{.rtx} file if it exists, or
+% execute the society/journal macro (if the latter is not defined, it will \cmd\relax\ out). 
+% Here we define the default journal.
+%    \begin{macrocode}
+\def\@journal@default{pra}%
+%    \end{macrocode}
+%
+% \subsection{Typesize-Specific Code}%
+%
+% After this society file is read in, we will process the \cmd\@pointsize-specific
+% code. Here we define the default.
+%    \begin{macrocode}
+\def\@pointsize@default{10}%
+%    \end{macrocode}
+%
+% Note: the convention in \revtex\ and its substyles is that 
+% the substyle must not override any explicit class options
+% declared by the document.
+% This means that the various Booleans of Section~\ref{sec:options}
+% may be assigned here only if they are still undefined at this point.
+%
+% For the APS, we supply code specific to journals PRA, PRB, PRC, PRD, PRE, PRL, PRX, PRAPPLIED, PRMATERIALS, PRFLUIDS, PRAB (was PRSTAB), PRPER (was PRSTPER), and RMP.
+% At present, they are identical,
+% with the exception of PRL and RMP.
+% We also introduce a new generic physrev style now that all of the Phys. Rev. journals 
+% are identical
+% In 4.2, we make the inclusion of titles in the bibliography the default
+%
+% For most all of the APS journals, the journal-dependent 
+% code is relatively meager and is therefore embedded in this file.
+% However, the RMP code is sufficiently extensive that 
+% splitting it out into a separate file is more convenient.
+%
+% \subsubsection{\classoption{pra}}%
+% There is no code specific to \classoption{pra}.
+%    \begin{macrocode}
+\def\rtx@apspra{%
+ \class@info{APS journal PRA selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prb}}%
+% There is no code specific to \classoption{prb}.
+%    \begin{macrocode}
+\def\rtx@apsprb{%
+ \class@info{APS journal PRB selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prc}}%
+% There is no code specific to \classoption{prc}. 
+%    \begin{macrocode}
+\def\rtx@apsprc{%
+ \class@info{APS journal PRC selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prd}}%
+% There is no code specific to \classoption{prd}. 
+%    \begin{macrocode}
+\def\rtx@apsprd{%
+ \class@info{APS journal PRD selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{pre}}%
+% There is no code specific to \classoption{pre}. 
+%    \begin{macrocode}
+\def\rtx@apspre{%
+ \class@info{APS journal PRE selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prl}}%
+%    \begin{macrocode}
+\def\rtx@apsprl{%
+ \class@info{APS journal PRL selected}%
+%    \end{macrocode}
+% In PRL, the default is the \classoption{bibnotes} option,
+% and the Acknowledgments section has no head.
+%
+% The References head is a device that may be described as a lozenge centered on the baseline,
+% 71 points wide by 2 points thick, with the ends tapering to a half point in thickness.
+% Space above 26 points base to base, below 31 base to base.
+%FIXME: this code may confound \classname{geometry}
+%    \begin{macrocode}
+ \let\frontmatter@footnote@produce\frontmatter@footnote@produce@endnote
+ \@booleanfalse\acknowledgments@sw
+ \appdef\setup@hook{%
+  \def\bibsection{%
+   \par
+   \begingroup
+    \baselineskip26\p@
+    \bib@device{\hsize}{72\p@}%
+   \endgroup
+   \nobreak\@nobreaktrue
+   \addvspace{19\p@}%
+  }%
+ }%
+%    \end{macrocode}
+% Implement length checking.
+% Use the \classname{times} and \classname{mathtime} packages,
+% plus whatever other processing is required
+% to make the formatted output be true
+% to the metrics of the journal.
+%
+%    \begin{macrocode}
+\appdef\setup@hook{%
+  \lengthcheck@sw{%
+   \RequirePackage{times}%
+%    \end{macrocode}
+% Wait. Do not use mathtime after all. APS has their own way of doing math pi, involving
+% Adobe Mathematical Pi and other fonts.
+%    \begin{verbatim}
+%  \RequirePackage{mathtime}%
+%    \end{verbatim}
+%    \begin{macrocode}
+  }{}%
+}%
+%    \end{macrocode}
+% A PRL does not have numbered sections.
+%    \begin{macrocode}
+ \c@secnumdepth=-\maxdimen
+%    \end{macrocode}
+% Note: we defer this code until after type size file is read in.
+%    \begin{macrocode}
+ \appdef\setup@hook{%
+  \@ifnum{\@pointsize=10\relax}{%
+   \lengthcheck@sw{%
+    \def\large{%
+     \@setfontsize\large{12.5}{14\p@}%
+    }%
+    \def\normalsize{%
+     \@setfontsize\normalsize{10.5}\@xiipt
+     \abovedisplayskip 6\p@ \@plus6\p@ \@minus5\p@
+     \belowdisplayskip \abovedisplayskip
+     \abovedisplayshortskip  \abovedisplayskip
+     \belowdisplayshortskip \abovedisplayskip
+     \let\@listi\@listI
+    }%
+    \def\small{%
+     \@setfontsize\small{9.5}\@xipt
+     \abovedisplayskip 5\p@ \@plus5\p@ \@minus4\p@
+     \belowdisplayskip \abovedisplayskip
+     \abovedisplayshortskip  \abovedisplayskip
+     \belowdisplayshortskip \abovedisplayskip
+     \let\@listi\@listI
+    }%
+    \DeclareMathSizes{12.5}{12.5}{9}{6}%
+    \DeclareMathSizes{10.5}{10.5}{7.5}{5}%
+    \DeclareMathSizes{9.5}{9.5}{7.0}{5}%
+   }{%
+    \def\normalsize{%
+     \@setfontsize\normalsize\@xpt\@xiipt
+     \abovedisplayskip 10\p@ \@plus2\p@ \@minus5\p@
+     \belowdisplayskip \abovedisplayskip
+     \abovedisplayshortskip  \abovedisplayskip
+     \belowdisplayshortskip \abovedisplayskip
+     \let\@listi\@listI
+    }%
+   }%
+  }{}%
+ }%
+ \textheight = 694.0\p@
+%    \end{macrocode}
+%
+% End of \classoption{prl} code.
+%    \begin{macrocode}
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prper}}%
+% There is no code specific to \classoption{prper}
+%    \begin{macrocode}
+\def\rtx@apsprper{%
+ \class@info{APS journal PRPER selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prab}}%
+% There is no code specific to \classoption{prab}. 
+%    \begin{macrocode}
+\def\rtx@apsprab{%
+ \class@info{APS journal PRAB selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prx}}%
+% There is no code specific to \classoption{prx}. 
+%    \begin{macrocode}
+\def\rtx@apsprx{%
+ \class@info{APS journal PRX selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prapplied}}%
+% There is no code specific to \classoption{prapplied}. 
+%    \begin{macrocode}
+\def\rtx@apsprapplied{%
+ \class@info{APS journal PRApplied selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prmaterials}}%
+% There is no code specific to \classoption{prmaterials}. 
+%    \begin{macrocode}
+\def\rtx@apsprmaterials{%
+ \class@info{APS journal PRMaterials selected}%
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{prfluids}}%
+%  PRFluids uses a one-column format for journal format, but if authors want this, they should use the onecolumn option and not the reprint option.
+% Parsing of documentclass options is rather involved and hard to control precisely enough to have the correct behavior using the reprint option.
+%    \begin{macrocode}
+\def\rtx@apsprfluids{%
+ \class@info{APS journal PRFluids selected}%
+ \@booleanfalse\titlepage@sw
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{physrev}}%
+% There is no code specific to \classoption{physrev}. 
+%    \begin{macrocode}
+\def\rtx@apsphysrev{%
+ \class@info{APS unified Physical Review journal style selected}%
+%    \begin{macrocode}
+}%
+%    \end{macrocode}
+%
+% \subsubsection{\classoption{rmp}}%
+% If this option has been selected, we will read in the needed code from the file \file{apsrmp.rtx}. 
+%
+% \subsection{Establish APS Defaults}\label{sec:aps-defaults}
+%
+% \begin{macro}{\footinbib@sw}
+% All APS journals except RMP effectively invoke the \classoption{footinbib} option.
+% We rely on the RMP-specific code to override this assignment. 
+%    \begin{macrocode}
+\@booleantrue\footinbib@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@bibdataout@init}
+% \begin{macro}{\@bibdataout@aps}
+% \changes{4.1o}{2010/02/12}{(AO, 580) Control .bst at run time.}%
+% Procedure \cmd\@bibdataout@aps\ has the job of writing the control record into the
+% job's \cmd\jobname\filename{.bib} file, where it will adjust the options to \filename{.bst} processing. 
+% It is installed into the initialization procedure \cmd\@bibdataout@init, and its meaning 
+% is set by the society (APS) and journal. 
+% For all but RMP, we select the Physical Review style.
+% For the latter case, we change the meaning, per the code in \file{apsrmp.rtx}.
+% 
+%    \begin{macrocode}
+\appdef\@bibdataout@rev{\@bibdataout@aps}%
+\def\@bibdataout@aps{%
+ \immediate\write\@bibdataout{%
+%    \end{macrocode}
+% An entry that controls processing of the \filename{.bst} file has entry type \texttt{@CONTROL}. 
+%    \begin{macrocode}
+  @CONTROL{%
+   apsrev42Control%
+%    \end{macrocode}
+% Say whether we want long bibliography style (the default), or the abbreviated style.
+% \changes{4.2b}{2017/11/22}{(MD) MD - not sure why these parameters were different previously. Made them match except for title.}%
+% Use binary flags on control.* flags in bst file to set appropriate parameters
+% author = 08 corresponds to initials, jrnlst
+% editor = 1 corresponds to format identical to authors
+% title = 0  means to include title in journal references if present; title ="" means omit the title even if present (this should be the only difference between long and short bib styles)
+% year = 1 corresponds to truncate
+% page = 0 corresponds to using single page number rather than a range
+%    \begin{macrocode}
+   \longbibliography@sw{%
+    ,author="08",editor="1",pages="0",title="0",year="1"% 
+   }{%
+    ,author="08",editor="1",pages="0",title="",year="1"%
+   }%
+  }%
+ }%
+%    \end{macrocode}
+% Place a \cmd\citation\ into the auxiliary file corresponding to this entry. 
+%    \begin{macrocode}
+ \if@filesw
+  \immediate\write\@auxout{\string\citation{apsrev42Control}}%
+ \fi
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\place@bibnumber}
+% \begin{macro}{\@bibstyle}
+% We install code that will select the presentation for \cmd\bibitem s
+% and govern the \BibTeX\ processing.
+%    \begin{macrocode}
+\let\place@bibnumber\place@bibnumber@inl
+\def\@bibstyle{apsrev\substyle@post}%
+%    \end{macrocode}
+% \begin{verbatim}
+%\appdef\setup@hook{%
+% \longbibliography@sw{%
+% \appdef\@bibstyle{long}%
+% }{}%
+%}%
+% \end{verbatim}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{APS Sanity Checking}\label{sec:aps-sanity}
+% \changes{4.1f}{2009/07/20}{(AO, 524) Makes no sense if citations are superscript numbers and so are footnotes}
+%
+% Rule: if \cmd\place@bibnumber\ is \cmd\place@bibnumber@sup\ 
+% (citations are numbered and set superscript),
+% then it makes no sense for \cmd\footinbib@sw\ to be \cmd\false@sw\ 
+% (footnotes set in the bibliography, as endnotes). 
+% If both conditions prevailed, then the document would have footnotes
+% and citations both as superscript arabic numbers, but independently numbered, 
+% which would be confusing. 
+%
+% Any society that provides for both superscript numbered citations as well as for 
+% numbered footnotes should check for this same condition, and deal with it. 
+%
+% Note: an alternative would be for footnotes to use the same sequence of footnote devices
+% that are used by the frontmatter footnotes 
+% (\cmd\frontmatter@thefootnote\ instead of arabic numbers). 
+%
+% In this case, we would want to refrain from resetting \cmd\c@footnote\ at the end of 
+% the title page formatting.
+% We would also want to treat body footnotes identically to frontmatter footnotes: 
+% the assignments in \cmd\titleblock@produce\ would persist throughout the document.
+%
+% But APS do not choose to go that route. 
+%    \begin{macrocode}
+\appdef\setup@hook{%
+ \@ifx{\place@bibnumber\place@bibnumber@sup}{%
+  \footinbib@sw{}{%
+   \class@warn{Citations are superscript numbers: footnotes must be endnotes; changing to that configuration}%
+   \@booleantrue\footinbib@sw
+  }%
+ }{}%
+}%
+%    \end{macrocode}
+% 
+% Here ends the substyle for society APS.
+%    \begin{macrocode}
+%</aps>
+%    \end{macrocode}
+%
+%
+% \section{The \classoption{rmp} journal substyle: the \texttt{rmp} module}
+%
+% The file \file{apsrmp.rtx} is read in by the \classname{revtex4} document class
+% if \cmd\@society\ has the value \classoption{aps}
+% and \cmd\@journal\ has the value \classoption{rmp}.
+%
+% It is read at the end of the \file{aps.rtx}, so all definitions
+% and assignments in that file are operative unless overridden here.
+%
+%
+%    \begin{macrocode}
+%<*rmp>
+%    \end{macrocode}
+%
+% Protect this file from being read in by anything but \revtex.
+%    \begin{macrocode}
+\ifx\undefined\substyle@ext
+ \def\@tempa{%
+  \endinput
+  \GenericWarning{I must be read in by REVTeX! (Bailing out)}%
+ }%
+ \expandafter\else
+  \def\@tempa{}%
+ \expandafter\fi\@tempa
+%    \end{macrocode}
+%
+% Protect this file from being read in as a society instead of a journal.
+% In such a case, \cmd\@journal\ will be undefined. 
+%    \begin{macrocode}
+\@ifxundefined\@journal{%
+%    \end{macrocode}
+% One alternative: abort the document.
+% Another alternative: try to recover: force load the aps society file
+%    \begin{macrocode}
+ \class@warn{Please specify the REVTeX options [aps,rmp]!}%
+ \@@end
+}{}%
+%    \end{macrocode}
+% Log the journal substyle.
+%    \begin{macrocode}
+ \class@info{APS journal RMP selected}%
+%    \end{macrocode}
+%
+% \subsection{Frontmatter}%
+%
+% We assign the titlepage style for RMP; a document instance 
+% may override by invoking one of the class options of \revtex.
+%    \begin{macrocode}
+\clo@groupedaddress
+%    \end{macrocode}
+%
+% \begin{macro}{\frontmatter@setup}
+% 
+%    \begin{macrocode}
+\def\frontmatter@setup{%
+ \normalfont\sffamily\raggedright
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\PACS@warn}
+% Per Mark Doyle, RMP  never displays the PACS, so they don't want the `use showpacs' warning spit out.
+%\changes{4.2b}{2017/11/22}{(MD) PACS are obsolete altogether now}%
+%    \begin{macrocode}
+\def\PACS@warn{RMP documents do not display PACS and PACS are obsolete. Your \string\pacs\space will be ignored}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@title@above}
+% \begin{macro}{\frontmatter@title@format}
+% \begin{macro}{\frontmatter@title@below}
+% 
+%    \begin{macrocode}
+\def\frontmatter@title@above{}%
+\def\frontmatter@title@format{\Large\bfseries\raggedright}% HelveticaNeue-Medium(Italic) 14pt.
+\def\frontmatter@title@below{\addvspace{12\p@}}% 24pt b-b down to first author
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@authorformat}
+% \changes{4.1b}{2008/08/04}{Rag the right even more: .8\cs{hsize}. Also, assign \cs{@totalleftmargin}.}%
+% \changes{4.1b}{2008/06/29}{(AO, 455) Be nice to a list within the abstract (assign \cs{@totalleftmargin}).}
+% Set the rag to a milder value, because we want to do true ragged right
+% typesetting, as opposed to the \LaTeX\ default, which gives very poor results.
+%
+% Note: author font is 9.8bp. 19.2bp/14.3bp above/below.
+%    \begin{macrocode}
+\def\frontmatter@authorformat{%
+ \preprintsty@sw{\vskip0.5pc\relax}{}%
+ \@tempskipa\@flushglue
+ \@flushglue\z@ plus.8\hsize
+ \raggedright\advance\leftskip.5in\relax
+ \@flushglue\@tempskipa
+ \parskip\z@skip
+ \@totalleftmargin\leftskip
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@affiliationfont}
+% \changes{4.1b}{2008/08/04}{As with author formatting, rag the right more, and assign \cs{@totalleftmargin}. Also neutralize \cs{def@after@address}.}%
+% \changes{4.1b}{2008/06/29}{(AO, 455) Be nice to a list within the abstract (assign \cs{@totalleftmargin}).}
+% The hook \cmd\frontmatter@affiliationfont\ controls the formatting of affiliations and affiliation groups.
+% The hook \cmd\frontmatter@above@affilgroup\ is invoked just before proceeding with author/affiliation processing.
+% The \cmd\frontmatter@above@affiliation\ is the amount of space above affiliations in the \classoption{groupedaddress} style,
+% and \cmd\frontmatter@above@affiliation@script\ is that for \classoption{superscriptaddress}.
+%
+% Note: affiliation font is 9.03/10.4bp, 14.3bp/19.2bp b-b above/below
+%    \begin{macrocode}
+\def\frontmatter@affiliationfont{% Helvetica 9/10.2
+ \small\slshape\selectfont\baselineskip10.5\p@\relax
+ \@tempskipa\@flushglue
+ \@flushglue\z@ plus.8\hsize
+ \raggedright\advance\leftskip.5in\relax
+ \@flushglue\@tempskipa
+ \@totalleftmargin\leftskip
+ \let\def@after@address\def@after@address@empty
+}%
+\def\frontmatter@above@affilgroup{\addvspace{7.2\p@}}% additional leading above an author
+\def\frontmatter@above@affiliation{\addvspace{5.3\p@}}%
+\def\frontmatter@above@affiliation@script{}%
+%    \end{macrocode}
+% \end{macro}
+%
+% Set up the default RMP style for title block authors and affiliations.
+% We assign the titlepage style for RMP; a document instance 
+% may override by invoking one of the class options of \revtex.
+% \changes{4.1b}{2008/08/04}{The \texttt{rmp} journal substyle selects \texttt{groupedaddress} by default.}%
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+%
+% This command should override the effect of the 
+% corresponding command in the society substyle,
+% and any document class option bearing on same will in turn override. 
+%    \begin{macrocode}
+\clo@groupedaddress
+%    \end{macrocode}
+%
+% \begin{macro}{\frontmatter@RRAP@format}
+% \changes{4.1b}{2008/06/29}{(AO, 455) Be nice to a list within the abstract (assign \cs{@totalleftmargin}).}
+% Note: in RMP, if we are not in preprint mode, the date will not be produced.
+%
+% Note: Helvetica C/lc, 8.98bp, space above: 16.3bp b-b.
+%    \begin{macrocode}
+\def\frontmatter@RRAP@format{%
+  \addvspace{7.3\p@}%
+  \small
+  \raggedright\advance\leftskip.5in\relax
+ \@totalleftmargin\leftskip
+}%
+\def\produce@RRAP#1{%
+  \@if@empty{#1}{}{%
+   \@ifvmode{\leavevmode}{}%
+   \unskip(\ignorespaces#1\unskip)\quad
+  }%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@abstractheading}
+% Space above 21.8bp b-b.
+%    \begin{macrocode}
+\def\frontmatter@abstractheading{%
+ \preprintsty@sw{%
+  \begingroup
+   \centering\large
+   \abstractname
+   \par
+  \endgroup
+  \vspace{.5pc}%
+ }{}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@abstractfont}
+% TimesTen 8.93bp/9.6bp X 360bp, indented 36bp, with 21.9/37.6bp b-b above/below
+% \changes{4.1b}{2008/06/29}{(AO, 455) Be nice to a list within the abstract (assign \cs{@totalleftmargin}).}
+%    \begin{macrocode}
+\def\frontmatter@abstractfont{%
+ \footnotesize
+ \hsize360\p@
+ \leftskip=0.5in
+ \parindent\z@
+ \@totalleftmargin\leftskip
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\frontmatter@preabstractspace}
+% \begin{macro}{\frontmatter@postabstractspace}
+% Space above and space below abstract in title block.
+% Should be 22/36 points base-to-base.
+%    \begin{macrocode}
+\def\frontmatter@preabstractspace{7.7\p@}%
+\def\frontmatter@postabstractspace{24.6\p@}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% FIXME: Not done: PACS.
+% FIXME: TOC: Head is same as \section: HelveticaNeue 8.98. 32/22bp b-b above/below,
+%             Body: TimesTen 8/10.5.
+%
+% \subsection{General Text}%
+%
+% \changes{4.1b}{2008/07/01}{(AO) make settings at class time instead of deferring them to later.}
+% If not in preprint mode, RMP sets the type size to 10/12 point. Note: s/b 11.6bp leading
+%FIXME: define \cmd\normalsize\ only if nobody else has done so. 
+%    \begin{macrocode}
+ \appdef\setup@hook{%
+  \preprintsty@sw{}{%
+   \def\normalsize{%
+    \@setsize\normalsize{12pt}\xpt\@xpt
+    \abovedisplayskip 10\p@ plus2\p@ minus5\p@
+    \belowdisplayskip \abovedisplayskip
+    \abovedisplayshortskip  \abovedisplayskip
+    \belowdisplayshortskip \abovedisplayskip
+    \let\@listi\@listI
+   }%
+  }%
+ }%
+%    \end{macrocode}
+%
+% Footnote mods:
+% \changes{4.1n}{2010/01/02}{(AO, 571) class file must set \cs{splittopskip}; fine tune \cs{skip}\cs{footins}; \cs{footnoterule} defined in terms of \cs{skip}\cs{footins}}%
+%    \begin{macrocode}
+ \footnotesep 9.25pt
+ \skip\footins 36pt plus 4pt minus 12pt
+ \def\footnoterule{%
+  \dimen@\skip\footins\divide\dimen@\thr@@
+  \kern-\dimen@\hrule width.5in\kern\dimen@
+ }%
+%    \end{macrocode}
+%
+%
+% \subsection{Sectioning}
+% \changes{4.1b}{2008/08/04}{Use \cs{setup@hook} to initialize all.}
+% \changes{4.1b}{2008/08/01}{Section numbering via procedures \cs{secnums@rtx} and \cs{secnums@arabic}.}
+%
+% We override the meaning of \cmd\secnums@rtx. 
+% The class option \classoption{secnumarabic} will continue to work.
+%    \begin{macrocode}
+\def\secnums@rtx{%
+ \@ifxundefined\thepart{%
+  \def\thepart{\Roman{part}}%
+ }{}%
+ \@ifxundefined\thesection{%
+  \def\thesection       {\Roman{section}}%
+  \def\p@section        {}%
+ }{}%
+ \@ifxundefined\thesubsection{%
+  \def\thesubsection    {\Alph{subsection}}%
+  \def\p@subsection     {\thesection.}%
+ }{}%
+ \@ifxundefined\thesubsubsection{%
+  \def\thesubsubsection {\arabic{subsubsection}}%
+  \def\p@subsubsection  {\thesection.\thesubsection.}%
+ }{}%
+ \@ifxundefined\theparagraph{%
+  \def\theparagraph     {\alph{paragraph}}%
+  \def\p@paragraph      {\thesection.\thesubsection.\thesubsubsection.}%
+ }{}%
+ \@ifxundefined\thesubparagraph{%
+  \def\thesubparagraph  {\arabic{subparagraph}}%
+  \def\p@subparagraph   {\thesection.\thesubsection.\thesubsubsection.\theparagraph.}%
+ }{}%
+}%
+%    \end{macrocode}
+%
+% In RMP, put a period (.), followed by `nut space', after the section number.
+% Also, hang the section number (the \LaTeX\ default).
+%    \begin{macrocode}
+\def\@seccntformat#1{\csname the#1\endcsname.\hskip0.5em\relax}%
+%    \end{macrocode}
+%
+% Note that we wish to set the section head uppercase, so we use
+% David Carlisle's \cmd\MakeTextUppercase. However, because this procedure effectively 
+% parses its argument (looking for things to \emph{not} translate), it has to be invoked
+% in such a way that the argument of the \cmd\section\ command is passed to it as its
+% own argument. 
+%
+% To accomplish this, we use the \cmd\@hangfrom@\ hook, which was developed for this 
+% purpose.
+% \changes{4.1b}{2008/07/01}{Add \cs{@hangfroms@section}}
+%    \begin{macrocode}
+ \def\section{%
+  \@startsection{section}{1}{\z@}{0.8cm plus1ex minus.2ex}{0.4cm}%
+  {%
+   \small\sffamily\bfseries\selectfont
+   \raggedright
+   \parindent\z@
+  }%
+ }%
+ \def\@hangfrom@section#1#2#3{\@hangfrom{#1#2}\MakeTextUppercase{#3}}%
+ \def\@hangfroms@section#1#2{#1\MakeTextUppercase{#2}}%
+ \def\subsection{%
+  \@startsection{subsection}{2}{\z@}{0.8cm plus1ex minus.2ex}{0.4cm}%
+  {%
+   \small\sffamily\bfseries
+   \raggedright
+   \parindent\z@
+  }%
+ }%
+ \def\subsubsection{%
+  \@startsection{subsubsection}{3}{\z@}{.8cm plus1ex minus.2ex}{0.4cm}%
+  {%
+   \small\sffamily\selectfont
+   \raggedright
+   \parindent\z@
+  }%
+ }%
+ \def\paragraph{%
+  \@startsection{paragraph}{4}{\z@}{.8cm plus1ex minus.2ex}{-1em}%
+  {%
+   \small\slshape\selectfont
+   \raggedright
+   \parindent\z@
+  }%
+ }%
+ \def\subparagraph{%
+  \@startsection{subparagraph}{4}{\parindent}{3.25ex plus1ex minus.2ex}{-1em}%
+  {\normalsize\bfseries\selectfont}%
+ }%
+%
+ \setcounter{tocdepth}{4}% FIXME: has no effect
+%    \end{macrocode}
+%
+% \begin{macro}{\appendix}
+% \begin{macro}{\@hangfrom@appendix}
+% \begin{macro}{\@hangfroms@appendix}
+% \begin{macro}{\@appendixcntformat}
+% \changes{4.1b}{2008/07/01}{Add \cs{@hangfroms@section}}
+%    \begin{macrocode}
+\appdef\appendix{%
+ \let\@hangfrom@section\@hangfrom@appendix
+ \let\@sectioncntformat\@appendixcntformat
+}%
+\def\@hangfrom@appendix#1#2#3{%
+ #1%
+ \@if@empty{#2}{%
+  #3%
+ }{%
+  #2\@if@empty{#3}{}{:\ #3}%
+ }%
+}%
+\def\@hangfroms@appendix#1#2{%
+ #1\appendixname\@if@empty{#2}{}{:\ #2}%
+}%
+\def\@appendixcntformat#1{\appendixname\ \csname the#1\endcsname}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+%
+% \subsection{Figure and Table Caption Formatting}
+% \begin{macro}{\@makecaption}
+% \changes{4.1b}{2008/07/01}{Break out \cs{@caption@fignum@sep}}
+%
+%    \begin{macrocode}
+\setlength\belowcaptionskip{2\p@}
+\long\def\@makecaption#1#2{%
+  \vskip\abovecaptionskip
+  \vbox{%
+   \flushing
+   \small\rmfamily
+   \noindent
+   #1\@caption@fignum@sep#2\par
+  }%
+  \vskip\belowcaptionskip
+}%
+\def\@caption@fignum@sep{\nobreak\hskip.5em plus.2em\ignorespaces}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Citations and Bibliography}%
+%
+% Customize \revtex\ for the journal substyle;
+% this task requires three components:
+% a \BibTeX\ \file{.bst} style file,
+% customizing code for \file{natbib}, and
+% customizations of the \env{thebibliography} environment.
+%
+% \begin{macro}{\@bibstyle}
+% Define the argument of the \cmd\bibliographystyle\ command
+% (if the document does not do so).
+%
+% The user must have installed a \file{.bst} file of the corresponding name.
+% This file will then be used by \BibTeX\ when compiling the document's \file{.bbl} file.
+%
+%  To generate \file{apsrmp.bst}, use \classname{custom-bib} version 3.89d1 or later.
+%  Run the \file{.bst} generator, \file{makebst.tex}, with the following options:
+%
+% \def\QandA#1#2#3{\item#1: \textbf{#2}: \texttt{#3}---}%
+% \def\CandE#1{\item\relax\texttt{#1}---}%
+% \begin{enumerate}
+% \QandA{STYLE OF CITATIONS}{a}{ay}Author-year with some non-standard interface
+% \QandA{AUTHOR}{*}{nat}Natbib for use with natbib v5.3 or later
+% \QandA{LANGUAGE FIELD}{l}{lang}Use language field to switch hyphenation patterns for title
+% \QandA{PRESENTATIONS}{b}{pres,pres-bf}Presentation, speaker bold face 
+% \QandA{ORDER ON VON PART }{x}{vonx}Sort without von part (de la Maire after Mahone)
+% \QandA{AUTHOR NAMES}{a}{nm-rev1}Only first name reversed, initials (AGU style: Smith, J. F., H. K. Jones)
+% \QandA{POSITION OF JUNIOR }{*}{jnrlst}Junior comes last as Smith, John, Jr.
+% \QandA{TYPEFACE FOR AUTHORS IN LIST OF REFERENCES}{u}{nmft,nmft-def}User defined author font (\cmd\bibnamefont)
+% \QandA{FONT FOR FIRST NAMES }{u}{fnm-def}First names in user defined font (\cmd\bibfnamefont)
+% \QandA{EDITOR NAMES IN INCOLLECTION ETC}{a}{nmfted}Editors incollection like authors font
+% \QandA{FONT FOR `AND' IN LIST}{r}{nmand-rm}`And' in normal font (JONES and JAMES)
+% \QandA{FONT OF CITATION LABELS IN TEXT }{u}{lab,lab-def}User defined citation font (\cmd\citenamefont)
+% \QandA{FONT FOR `AND' IN CITATIONS }{r}{and-rm}Cited `and' in normal font 
+% \QandA{LABEL WHEN AUTHORS MISSING }{*}{keyxyr}Year blank when KEY replaces missing author (for natbib 7.0)
+% \QandA{DATE POSITION}{b}{dt-beg}Date after authors 
+% \QandA{DATE FORMAT }{m}{yr-com}Date preceded by comma as `, 1993'
+% \QandA{INCLUDE MONTHS}{m}{aymth}Include month in date 
+% \QandA{REVERSED DATE }{r}{dtrev}Date as year month 
+% \QandA{TRUNCATE YEAR }{*}{note-yr}Year text full as 1990--1993 or `in press'
+% \QandA{TITLE OF ARTICLE}{d}{tit-qq}Title and punctuation in double quotes (``Title,'' ..)
+% \QandA{TITLE PRESENT IN ARTICLE, INCOLLECTION, AND INPROCEEDINGS}{x}{jtit-x}Title is ignored
+% \QandA{INPROCEEDINGS CHAPTER AND PAGES, LIKE INBOOK}{y}{inproceedings-chapter}produce pages after chapter just as in InBook
+% \QandA{ARTICLE BOOKTITLE PRESENT}{?}{article-booktitle}format booktitle 
+% \QandA{ARTICLE SERIES PRESENT}{?}{article-series}article can has series
+% \QandA{JOURNAL NAME FONT}{r}{jttl-rm}Journal name normal font
+% \QandA{JOURNAL NAME WITH ADDRESS}{y}{journal-address}Include address field (in parentheses) along with journal name
+% \QandA{BOOK TITLE FIELDS}{y}{book-bt}Field `booktitle', or if absent field `title', is book title 
+% \QandA{THESIS TITLE OPTIONAL}{?}{thesis-title-o}Title is optional: no warning issued if empty
+% \QandA{TECHNICAL REPORT TITLE}{b}{trtit-b}Tech. report title like books 
+% \QandA{JOURNAL VOLUME}{b}{vol-bf}Volume bold as {\bf vol}(num)
+% \QandA{JOURNAL VOL AND NUMBER}{s}{vnum-sp}Journal vol (num) as 34 (2)
+% \QandA{VOLUME PUNCTUATION}{c}{volp-com}Volume with comma as vol(num), ppp
+% \QandA{PAGE NUMBERS}{f}{jpg-1}Only start page number 
+% \QandA{POSITION OF PAGES}{e}{pp-last}Pages at end but before any notes
+% \QandA{BOOK EDITOR W/O AUTHOR}{}{book-editor-booktitle}Book permits empty author, produces title before editor in this case
+% \QandA{INBOOK PERMITS TITLE, BOOKTITLE, AUTHOR, EDITOR}{a}{inbook-editor-booktitle}Allow using both title/booktitle, both author/editor
+% \QandA{CONFERENCE ADDRESS FOR BOOK, INBOOK, INCOLLECTION, INPROCEEDINGS, PROCEEDINGS}{a}{bookaddress}Italic booktitle followed by bookaddress in roman
+% \QandA{NUMBER AND SERIES FOR BOOK, INBOOK, INCOLLECTION, INPROCEEDINGS, PROCEEDINGS}{*}{num-xser}Allows number without series and suppresses word "number"
+% \QandA{WORD NUMBER CAPITALIZED FOR NUMBER AND SERIES}{c}{number-cap}Capitalize word `number' as: "Number 123"
+% \QandA{WORD CHAPTER CAPITALIZED}{c}{chapter-cap}Capitalize word `chapter' as: `Chapter 42'
+% \QandA{COMBINING NUMBER AND SERIES}{x}{series-number}Series number as: `Springer Lecture Notes No. 125'
+% \QandA{POSITION OF NUMBER AND SERIES}{b}{numser-booktitle}After book title and conference address, and before editors 
+% \QandA{VOLUME AND SERIES FOR BOOKS}{s}{ser-vol}Series, vol. 23
+% \QandA{VOLUME AND SERIES FORMATTING}{y}{ser-rm}format series roman , even when used with volume
+% \QandA{WORD VOLUME CAPITALIZED FOR VOLUME AND SERIES}{y}{volume-cap}Capitalize word `volume', as: `Volume 7 in Lecture Series'
+% \QandA{POSITION OF VOLUME AND SERIES FOR INCOLLECTION, INBOOK, AND INPROCEEDINGS}{e}{ser-ed}Series and volume after booktitle and before editors
+% \QandA{JOURNAL NAME PUNCTUATION}{x}{jnm-x}Space after journal name
+% \QandA{PAGES IN BOOK}{*}{pg-bk,book-chapter-pages}As chapter and page: chapter 42, page 345
+% \QandA{PUBLISHER IN PARENTHESES}{p}{pub-par}Publisher in parentheses 
+% \QandA{EMPTY PUBLISHER PARENTHESES}{y}{ay-empty-pub-parens-x}eliminate parentheses altogether if nothing inside
+% \QandA{PUBLISHER POSITION}{e}{pre-edn}Edition before publisher
+% \QandA{SCHOOL}{p}{school-par}school/address in parens: `(school, address)' 
+% \QandA{ISBN NUMBER}{*}{isbn}Include ISBN for books, booklets, etc.
+% \QandA{ISSN NUMBER}{*}{issn}Include ISSN for periodicals
+% \QandA{DOI NUMBER}{a}{doi-link,doi}Doi forms a link to the publication, anchored to the volume or title
+% \QandA{`EDITOR' AFTER NAMES}{a}{bkedcap}`Name Editor,' as above, editor upper case
+% \QandA{EDITOR IN COLLECTIONS}{b}{edby}In booktitle, edited by ..  (where .. is names)
+% \QandA{PUNCTUATION BETWEEN SECTIONS }{c}{blk-com}Comma between blocks 
+% \QandA{FINAL PUNCTUATION}{c}{fin-endbibitem}Command at end instead of period 
+% \QandA{ABBREVIATE WORD `PAGES' }{a}{pp}`Page' abbreviated as p. or pp.
+% \QandA{ABBREVIATE WORD `EDITORS'}{a}{ed}`Editor' abbreviated as ed. or eds.
+% \QandA{OTHER ABBREVIATIONS}{a}{abr}Abbreviations of such words
+% \QandA{ABBREVIATION FOR `EDITION' }{a}{ednx}`Edition' abbreviated as `ed' 
+% \QandA{EDITION NUMBERS}{n}{ord}Numerical editions as 1st, 2nd, 3rd, etc
+% \QandA{STORED JOURNAL NAMES}{a}{jabr}Abbreviated journal names 
+% \QandA{COMMA BEFORE `AND'}{c}{and-com}Comma even with 2 authors as `Tom, and Harry'
+% \QandA{FONT OF `ET AL'}{i}{etal-it}Italic et al 
+% \QandA{ADDITIONAL REVTeX DATA FIELDS}{r}{revdata,eprint,url,url-blk,translation}Include REVTeX data fields collaboration, eid, eprint, archive, url, translation
+% \QandA{SLACcitation FIELD}{?}{SLACcitation}Produce SLACcitation field
+% \QandA{NUMPAGES DATA FIELD}{*}{numpages-x}Do not include numpages field 
+% \QandA{REFERENCE COMPONENT TAGS}{b}{bibinfo}Reference component tags like \cmd\bibinfo\ in the content of \cmd\bibitem
+% \QandA{ELEMENT TAGS}{b}{bibfield}Element tags like \cmd\bibfield\ in the content of \cmd\bibitem
+% \QandA{COMPATIBILITY WITH PLAIN TEX}{*}{nfss}Use LaTeX commands which may not work with Plain TeX
+% \end{enumerate}
+%
+% A file \file{apsrmp.dbj} file equivalent to the following should result:
+% \begin{verbatim}
+%\input docstrip
+%\preamble
+%----------------------------------------
+%*** REVTeX-compatible RMP 2010-02-12 ***
+%\endpreamble
+%\postamble
+%End of customized bst file
+%\endpostamble
+%\keepsilent
+%\askforoverwritefalse
+%\def\MBopts{\from{merlin.mbs}{%
+%  head,\MBopta}
+%\from{physjour.mbs}{\MBopta}
+%\from{geojour.mbs}{\MBopta}
+%\from{photjour.mbs}{\MBopta}
+%\from{merlin.mbs}{tail,\MBopta}}
+%\def\MBopta{%
+%  ay,%: Author-year with some non-standard interface
+%  nat,%: Natbib for use with natbib v5.3 or later
+%  lang,%: Use language field to switch hyphenation patterns for title
+%  pres,pres-bf,%: Presentation, speaker bold face 
+%  vonx,%: Sort without von part (de la Maire after Mahone)
+%  nm-rev1,%: Only first name reversed, initials (AGU style: Smith, J. F., H. K. Jones)
+%  jnrlst,%: Junior comes last as Smith, John, Jr.
+%  nmft,nmft-def,%: User defined author font (\bibnamefont)
+%  fnm-def,%: First names in user defined font (\bibfnamefont)
+%  nmfted,%: Editors incollection like authors font
+%  nmand-rm,%: `And' in normal font (JONES and JAMES)
+%  lab,lab-def,%: User defined citation font (\citenamefont)
+%  and-rm,%: Cited `and' in normal font 
+%  keyxyr,%: Year blank when KEY replaces missing author (for natbib 7.0)
+%  dt-beg,%: Date after authors 
+%  yr-par,%: Year in parentheses as (1993)
+%  dtrev,%: Date as year month 
+%  date-nil-x,%: If date is empty, then do not produce the surrounding punctuation (parens, brackets, colon, comma)
+%  tit-qq,%: Title and punctuation in double quotes (``Title,'' ..)
+%  inproceedings-chapter,%: produce pages after chapter, just as in InBook
+%  jtit-x,%: Title is ignored
+%  inproceedings-chapter,%: produce pages after chapter just as in InBook
+%  article-booktitle,%: format booktitle 
+%  article-series,%: article can has series
+%  jttl-rm,%: Journal name normal font
+%  journal-address,%: Include address field (in parentheses) along with journal name
+%  book-bt,%: Field `booktitle', or if absent field `title', is book title 
+%  thesis-title-o,%: Title is optional: no warning issued if empty
+%  trtit-b,%: Tech. report title like books 
+%  techreport-institution-par,%: format tech report institution like book publisher
+%  vol-bf,%: Volume bold as {\bf vol}(num)
+%  vnum-sp,%: Journal vol (num) as 34 (2)
+%  volp-com,%: Volume with comma as vol(num), ppp
+%  jpg-1,%: Only start page number 
+%  pp-last,%: Pages at end but before any notes
+%  book-editor-booktitle,%: Book permits empty author, produces title before editor in this case
+%  inbook-editor-booktitle,%: Allow using both title/booktitle, both author/editor
+%  bookaddress,%: Italic booktitle followed by bookaddress in roman
+%  num-xser,%: Allows number without series and suppresses word "number"
+%  number-cap,%: Capitalize word `number' as: "Number 123"
+%  chapter-cap,%: Capitalize word `chapter' as: `Chapter 42'
+%  series-number,%: Series number as: `Springer Lecture Notes No. 125'
+%  numser-booktitle,%: After book title and conference address, and before editors 
+%  ser-vol,%: Series, vol. 23
+%  ser-rm,%: format series roman , even when used with volume
+%  volume-cap,%: Capitalize word `volume', as: `Volume 7 in Lecture Series'
+%  ser-ed,%: Series and volume after booktitle and before editors
+%  jnm-x,%: Space after journal name
+%  pg-bk,book-chapter-pages,%: As chapter and page: chapter 42, page 345
+%  pub-par,%: Publisher in parentheses 
+%  ay-empty-pub-parens-x,%: eliminate parentheses altogether if nothing inside
+%  pre-edn,%: Edition before publisher
+%  school-par,%: school/address in parens: `(school, address)' 
+%  isbn,%: Include ISBN for books, booklets, etc.
+%  issn,%: Include ISSN for periodicals
+%  doi-link,doi,%: Doi forms a link to the publication, anchored to the volume or title
+%  bkedcap,%: `Name Editor,' as above, editor upper case
+%  edby,%: In booktitle, edited by ..  (where .. is names)
+%  blk-com,%: Comma between blocks 
+%  fin-endbibitem,%: Command at end instead of period 
+%  pp,%: `Page' abbreviated as p. or pp.
+%  ed,%: `Editor' abbreviated as ed. or eds.
+%  abr,%: Abbreviations of such words
+%  ednx,%: `Edition' abbreviated as `ed' 
+%  ord,%: Numerical editions as 1st, 2nd, 3rd, etc
+%  jabr,%: Abbreviated journal names 
+%  and-com,%: Comma even with 2 authors as `Tom, and Harry'
+%  etal-it,%: Italic et al 
+%  revdata,eprint,url,url-blk,translation,%: Include REVTeX data fields collaboration, eid, eprint, archive, url, translation
+%  SLACcitation,%: Produce SLACcitation field
+%  numpages-x,%: Do not include numpages field 
+%  url,url-prefix-x,%: URL without prefix (default: `URL ')
+%  bibinfo,%: Reference component tags like \bibinfo in the content of \bibitem
+%  bibfield,%: Element tags like \bibfield in the content of \bibitem
+%  nfss,%: Use LaTeX commands which may not work with Plain TeX
+%,{%
+%  }}
+%\generate{\file{apsrmp4-2.bst}{\MBopts}}
+%\endbatchfile
+% \end{verbatim}
+%
+% For a comparison between apsrmp.bst and apsrev.bst, see Section~\ref{sec:CompRevRmp}. 
+%
+% \changes{4.1c}{2008/08/15}{Document class option longbibliography via \cs{substyle@post}}
+%    \begin{macrocode}
+\def\@bibstyle{apsrmp\substyle@post}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\authoryear@sw}
+% \changes{4.1a}{2008/01/18}{(AO, 457) Endnotes to be sorted in with numerical citations.}%
+% Author-year citations: default value of \cmd\authoryear@sw\ is true.
+%    \begin{macrocode}
+\@booleantrue\authoryear@sw
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@bibdataout@rmp}
+% \changes{4.1o}{2010/02/12}{(AO, 580) Control .bst at run time.}%
+% When the journal is RMP, the meaning of the procedure \cmd\@bibdataout@aps\ needs to be different 
+% because of the way the author names are formatted. In other respects, it is the same. 
+%    \begin{macrocode}
+\def\@bibdataout@aps{%
+ \immediate\write\@bibdataout{%
+%    \end{macrocode}
+% An entry that controls processing of the \filename{.bst} file has entry type \texttt{@CONTROL}. 
+% This entry's cite key is \texttt{apsrmp41Control}, which serves as a version number.
+%    \begin{macrocode}
+  @CONTROL{%
+   apsrmp41Control%
+%    \end{macrocode}
+% Say whether we want long bibliography style (the default), or the abbreviated style. 
+%    \begin{macrocode}
+   \longbibliography@sw{%
+    ,author="03",editor="0",pages="1",title="0",year="0"%
+   }{%
+    ,author="0B",editor="0",pages="0",title="0",year="1"% TeXSupport
+   }%
+  }%
+ }%
+%    \end{macrocode}
+% Place a \cmd\citation\ into the auxiliary file corresponding to this entry. 
+%    \begin{macrocode}
+ \if@filesw
+  \immediate\write\@auxout{\string\citation{apsrmp41Control}}%
+ \fi
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bibpunct}
+% \begin{macro}{\bibsection}
+% \begin{macro}{\bibpreamble}
+% \begin{macro}{\newblock}
+% \begin{macro}{\bibhang}
+% \begin{macro}{\bibsep}
+% \begin{macro}{\cite}
+% The following commands effectively establish the style in which \cmd\cite\ commands are
+% formatted.
+% You can think of them as the second needed component for the bibliography.
+% 
+% Set up for author-year citations:
+% when \cmd\NAT@set@cites\ executes (at \envb{document} time), the \cmd\@biblabel\ will
+% be set to \cmd\NAT@biblabel.
+%
+% Per Karie Friedman (friedman@phys.washington.edu), multiple citations are separated by semicolons, e.g., 
+% (Jones, 1999; Abbott and Smith, 2000; Wortley, 2001a), 
+% and 
+% multiple citations by the same author by commas, e.g., 
+% Abela et al. (1995, 1997a, 1997b).
+% The third argument of \cmd\bibpunct\ handles the former.
+%
+% The fifth argument puts a comma after the author when the year is not in parens:
+% (Lee et al., 1996).
+%
+% Incidently, this \cmd\bibpunct\ command specifies the \classname{natbib} default values. 
+%
+% We define the sectioning command to use when starting the bibliography.
+%
+% We change \classname{natbib}'s \cmd\NAT@def@citea\ procedure to effect more elaborate
+% punctuation for RMP: see item 473: 
+% \cmd\cite\ order punctuation: ``If possible, \cmd\textcite should put the word 'and' between two citations and before the last citation in a list of 3 or more.''
+%
+%    \begin{macrocode}
+\appdef\setup@hook{%
+%    \end{macrocode}
+%
+% We define the punctuation to use in the \cmd\cite\ command's production.
+%
+%    \begin{macrocode}
+ \bibpunct{(%)
+ }{%(
+ )}{;}{a}{,}{,}%
+%    \end{macrocode}
+%
+% We define the sectioning command to use when starting the bibliography.
+%
+%    \begin{macrocode}
+ \def\bibsection{%
+  \expandafter\section\expandafter*\expandafter{\refname}%
+  \@nobreaktrue
+ }%
+ \let\bibpreamble\@empty
+ \def\newblock{\ }%
+ \bibhang10\p@
+ \bibsep\z@
+%    \end{macrocode}
+%
+% Per Mark Doyle, \cmd\cite\ is mapped to \cmd\citep\ in RMP.
+% \changes{4.1i}{2009/10/23}{(AO, 541) Defer assignment of \cs{cite} until after natbib loads}
+%    \begin{macrocode}
+ \let\cite\citep
+%    \end{macrocode}
+%
+% End of code to be delayed until after \classname{natbib} loads.
+%    \begin{macrocode}
+}%
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\footinbib@sw}
+% Footnotes in bibliography are consistent only with numbered citations,
+% and are particularly nasty under \classname{natbib}:
+% the packcage will automatically change to numbered references if
+% any \cmd\bibitem\ commands lack the optional argument.
+% Therefore, we must uninvoke it now, even if invoked by the document.
+% The same is quietly done with 
+% \classname{natbib}'s \classoption{mcite} and \classoption{compress} options. 
+% 
+% \changes{4.1f}{2009/07/15}{(AO, 523) Add class option nomerge, to turn off new natbib 8.3 syntax}
+% (AO 523) I changed the code that alters \cmd\NAT@merge\ so that it will not override
+% when \cmd\NAT@merge\ has been set to \cmd\z@.
+%    \begin{macrocode}
+\@booleanfalse\footinbib@sw
+\appdef\setup@hook{%
+ \footinbib@sw{%
+  \class@warn{%
+   Footnotes in bibliography are incompatible with RMP.^^J%
+   Undoing the footinbib option.
+  }%
+  \@booleanfalse\footinbib@sw
+ }{}%
+ \@ifnum{\NAT@merge>\@ne}{\let\NAT@merge\@ne}{}%
+ \def\NAT@cmprs{\z@}%
+}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\eprint}
+% RMP requires the \cmd\eprint\ field in the bib entry to be set off with the word ``eprint''.
+%    \begin{macrocode}
+\def\eprint#1{eprint #1}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Table of Contents}
+%
+% We set up for auto-sizing of certain TOC elements.
+% 
+% To do this, we override the definitions for 
+% the default TOC font (\cmd\toc@@font),
+% and define
+% formatting for the needed elements (\cmd\l@\dots).
+% Finally, we activate the autosizing by 
+% assigning \cmd\toc@pre\ and \cmd\toc@post.
+%
+% \begin{macro}{\toc@@font}
+% \changes{4.1a}{2008/01/19}{(AO, 461) Change the csname revtex uses from @dotsep to ltxu@dotsep. The former is understood in mu. (What we wanted was a dimension.)}%
+% Set the formatting characteristics of the auto-indenting part
+%  of the TOC.
+%    \begin{macrocode}
+\def\toc@@font{%
+ \footnotesize\rmfamily
+ \def\\{\space\ignorespaces}%
+}%
+\def\ltxu@dotsep{5.5pt}%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\l@section}
+% Determine which TOC elements are automatically indented.
+%    \begin{macrocode}
+\def\tocleft@{\z@}%
+\def\tocdim@min{5\p@}%
+\def\l@section{%
+ \l@@sections{}{section}% Implicit #3#4
+}%
+\def\l@subsection{%
+ \l@@sections{section}{subsection}% Implicit #3#4
+}%
+\def\l@subsubsection{%
+ \l@@sections{subsection}{subsubsection}% Implicit #3#4
+}%
+%\def\l@subsubsection#1#2{}%
+\def\l@paragraph#1#2{}%
+\def\l@subparagraph#1#2{}%
+%    \end{macrocode}
+% \end{macro}
+%
+% Activate the TOC processing.
+%    \begin{macrocode}
+\let\toc@pre\toc@pre@auto
+\let\toc@post\toc@post@auto
+%    \end{macrocode}
+%
+%
+%    \begin{macrocode}
+%</rmp>
+%    \end{macrocode}
+%
+%
+% \Finale
+% %Here ends the programmer's documentation.
+% \endinput
+%
+\endinput
-- 
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