--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/perpage.tex	Fri Oct 28 18:26:42 2022 +0000
@@ -0,0 +1,547 @@
+% \iffalse
+%%
+%% perpage is part of the bigfoot bundle for critical typesetting
+%% Copyright 2002--2014  David Kastrup <dak@gnu.org>
+%%
+%% The license notice and corresponding source code for this file are
+%% contained in perpage.dtx.
+%%
+% This program is free software; you can redistribute it and/or modify
+% it under the terms of the GNU General Public License as published by
+% the Free Software Foundation; either version 2 of the License, or
+% (at your option) any later version.
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+% GNU General Public License for more details.
+%
+% You should have received a copy of the GNU General Public License
+% along with this program; if not, write to the Free Software
+% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+% \fi
+% \CheckSum{396}
+% \GetFileInfo{perpage.sty}
+% \date{\filedate}
+% \author{David Kastrup\thanks{\texttt{dak@gnu.org}}}
+% \title{The \texttt{perpage} package\\Version \fileversion}
+% \maketitle
+% \section{Description}
+%
+% The \texttt{perpage} package adds the ability to reset counters per
+% page and/or keep their occurences sorted in order of appearance on
+% the page.
+%
+% It works by attaching itself to the code for \cmd{\stepcounter} and
+% will then modify the given counter according to information written
+% to the |.aux| file, which means that multiple passes may be needed.
+% Since it uses the internals of the \cmd{\label} mechanism, the need
+% for additional passes will get announced by \LaTeX\ as ``labels may
+% have changed''.
+%
+% \DescribeMacro{\MakePerPage}
+% \begin{quote}
+%   |\MakePerPage[2]{footnote}|
+% \end{quote}
+% will start footnote numbers with~2 on each page (the optional
+% argument defaults to~1).  2~might be a strange number, unless you
+% have used something like
+% \begin{quote}
+%   |\renewcommand\thefootnote{\fnsymbol{footnote}}|
+% \end{quote}
+% and want to start off with a dagger.  The starting value must not be
+% less than~1 so that the counter logic can detect the reset of a
+% counter
+% reliably.\footnote{This unfortunately means that you can't just use
+%   \cmd{\alph} in order to get figures on page~10 numbered as ``10'',
+%   ``10a'', ``10b''.}
+% It could be a good idea to redefine |\@cnterr| if you use a format
+% with limited range: at the first pass, footnotes are not reset
+% across pages and things like |\fnsymbol| will quickly run out of
+% characters to use.
+%
+% \DescribeMacro{\theperpage}
+% If you want to label things also on a per page base, for example
+% with
+% \begin{quote}
+%   |\renewcommand{\thefigure}{\thepage-\arabic{figure}}|
+% \end{quote}
+% you'll have the problem that \cmd{\thepage} is updated
+% asynchronously with the real page, since \TeX\ does not know which
+% page the figure will end up.  If you have used the |perpage| package
+% for modifying the figure counter, however, at the point where the
+% counter is incremented, the macro \cmd{\theperpage} will be set to
+% the correct value corresponding to the actual page location.  Note
+% that this macro is shared between all counters, so advancing a
+% different counter under control of |perpage| will render
+% \cmd{\thefigure} incorrect.
+%
+% \DescribeMacro{\MakeSorted}
+% \begin{quote}
+%   |\MakeSorted{figure}|
+% \end{quote}
+% will make the |figure| counter get `sorted': this means that counter
+% values will be assigned in order of appearance in the output, not in
+% order of appearance in the source code.  For example, the order of
+% interspersed one- and two-column figures might get mixed up by
+% \LaTeX\ in the output.  Making the counter sorted will fix the order
+% to match the order of appearance.  A similar problem is when
+% ordinary footnotes are present in floating material (this does not
+% work in standard \LaTeX, but might do so when using |manyfoot.sty|
+% or |bigfoot.sty|): this might jumble their order in the output, and
+% making their counter sorted will make things appear fine again.
+%
+% While this would not fix the order in the table of figures,
+% fortunately the respective entries actually get written out in order
+% of appearance in the output anyway, so this indeed fixes the
+% problem.
+%
+% Manually setting the counter does not lead to reliable results in
+% general; as a special case, however, resetting it to zero is
+% recognized (this can also happen automatically when the counter is
+% dependent on some other counter).  The point where it is reset in
+% the source code separates `count groups': everything in the source
+% before that point is assigned sorted numbers separately from
+% everything appearing behind it, and the sequence numbers start again
+% with~1 with the first item appearing in the output (not the source)
+% from the new count group.
+%
+% \DescribeMacro{\MakeSortedPerPage}
+% \begin{quote}
+%   |\MakeSortedPerPage[2]{table}|
+% \end{quote}
+% will make the table numbers restart at 2 on each page \emph{and}
+% will keep them sorted, to boot.  Introducing new count groups by
+% resetting the counter to~0 manually will not work, as it is not
+% clear how to handle count groups scattered between pages.  You will
+% usually want to use something like
+% \begin{quote}
+%   |\renewcommand{\thefigure}{\theperpage-\arabic{figure}}|
+% \end{quote}
+% to go along with a page-wise figure
+% number.\footnote{Note the use of \cmd{\theperpage} here, see above.}
+% Note that it would be quite silly to start the ranges with~2: this
+% is just an example for the optional argument in case that you ever
+% need it.
+%
+% \DescribeMacro{\AddAbsoluteCounter}
+% \begin{quote}
+%   |\AddAbsoluteCounter{equation}|
+% \end{quote}
+% will create a counter |absequation| that will advance together with
+% the counter |equation| but will not get reset along with it.  This
+% is not sorted into output order, but just runs along with the
+% sequence in the source file.  As a special case, the counter
+% |abspage| is created in this manner and \cmd{\theabspage} is defined
+% as an arabic number that works in the same contexts as \cmd{\page}
+% (namely, gets properly deferred by \cmd{\protected@write}).
+%
+% \StopEventually{}
+% \section{The documentation driver}
+% This is the default driver for typesetting the docs.  Running it
+% through as a separate file will include the code section.  Running
+% the original |.dtx| file through will omit the code.
+%   \begin{macrocode}
+%<*driver>
+%ACE \documentclass{ltxdoc}
+%ACE \usepackage{perpage}
+%ACE \MakePerPage{footnote}
+%ACE \begin{document}
+%ACE \OnlyDescription
+%ACE %<driver> \AlsoImplementation
+%ACE \DocInput{perpage.dtx}
+%ACE \end{document}
+%ACE %</driver>
+%ACE %    \end{macrocode}
+%ACE %
+%ACE % \section{The package interfaces}
+%ACE % First identification.
+%ACE %    \begin{macrocode}
+%ACE %<*style>
+%ACE \NeedsTeXFormat{LaTeX2e}
+%ACE \ProvidesPackage{perpage}[2014/10/25 2.0 Reset/sort counters per page]
+%ACE %    \end{macrocode}
+%ACE % \begin{macro}{\pp@cl@begin}
+%ACE % \begin{macro}{\pp@cl@end}
+%ACE %   These macros are considerable tricky.  They are called as
+%ACE %   artificial `dependent' counters when the counter they are hooked
+%ACE %   into is advanced.  The way in which those counters are called are
+%ACE %   one of the following:
+%ACE %   \begin{quote}
+%ACE % \begin{verbatim}
+%ACE % \def\@stpelt#1{\global\csname c@#1\endcsname \z@}
+%ACE % \end{verbatim}
+%ACE %   \end{quote}
+%ACE %   which is the default way of resetting a subordinate counter used
+%ACE %   in \LaTeX, or
+%ACE %   \begin{quote}
+%ACE % \begin{verbatim}
+%ACE % \def\@stpelt#1{\global\csname c@#1\endcsname \m@ne\stepcounter{#1}}
+%ACE % \end{verbatim}
+%ACE %   \end{quote}
+%ACE %   which is a little present from |fixltx2e.sty| as of 2014/05/01,
+%ACE %   quite complicating this feat.
+%ACE %
+%ACE %   The startup code swallows either |\global \advance| or |\global|.
+%    \begin{macrocode}
+\def\pp@cl@begin{\z@\z@ \begingroup}
+%    \end{macrocode}
+%   The command used for ending our fake counters checks for the
+%   |\m@ne| condition.   We don't want to bump our auxiliary counters
+%   twice, so we remove the following |\stepcounter| command.  Things
+%   will go haywire if there is none, of course.
+%    \begin{macrocode}
+\def\pp@cl@end{\afterassignment\pp@cl@end@ii \count@}
+\def\pp@cl@end@ii{%
+  \relax
+  \expandafter\endgroup
+  \ifnum\count@<\z@
+    \expandafter\pp@cl@end@iii
+  \fi}
+\def\pp@cl@end@iii\stepcounter#1{}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\AddAbsoluteCounter}
+%   adds a counter with prefix |abs| to a given counter.  It typesets
+%   as an arabic number and never gets reset.  And it is advanced
+%   whenever the unprefixed counter gets advanced.
+%    \begin{macrocode}
+\newcommand\AddAbsoluteCounter[1]
+{\@ifundefined{c@abs#1}{%
+    \expandafter\newcount\csname c@abs#1\endcsname
+    \global\value{abs#1}\@ne
+    \global\expandafter\let\csname cl@abs#1\endcsname\@empty
+    \expandafter\xdef\csname theabs#1\endcsname{%
+      \noexpand\number \csname c@abs#1\endcsname}%
+    \global\@namedef{c@pabs@#1}{\pp@cl@begin
+      \stepcounter{abs#1}%
+      \pp@cl@end}%
+    \@addtoreset{pabs@#1}{#1}}{}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\c@perpage}
+%   We now create the absolute counter |perpage|:
+%    \begin{macrocode}
+%ACE \AddAbsoluteCounter{page}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\theabspage}
+%   This has to be specially defined so that it will expand as late as
+%   \cmd{\thepage} does.  Several commands set the latter temporarily
+%   to \cmd{\relax} in order to inhibit expansion, and we will more or
+%   less imitate its behavior when found set in that manner.
+%    \begin{macrocode}
+\def\theabspage{\ifx\thepage\relax
+    \noexpand\theabspage
+  \else
+    \number\c@abspage
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% Here follow the three commands for defining counters per page:
+% \begin{macro}{\MakePerPage}
+%   This creates a counter reset per page.  An optional second
+%   argument specifies the starting point of the sequence.
+%    \begin{macrocode}
+\newcommand*\MakePerPage[2][\@ne]{%
+  \pp@makeperpage{#2}\c@pchk@{#1}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\MakeSorted}
+%   This will create a counter sorted in appearance on the page.  No
+%   optional argument is given: set the counter to a desired starting
+%   value manually if you need to.  Resetting it to zero will start a
+%   new count group, setting it to other values is probably not reliable.
+%    \begin{macrocode}
+\newcommand*\MakeSorted[1]{%
+  \setcounter{#1}{\z@}%
+  \pp@makeperpage{#1}\c@schk@{\@ne}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\MakeSortedPerPage}
+%   This will create output in sorted order, reset on each page.  Use
+%   an optional argument to specify the starting value per page.  This
+%   must not be~0, unfortunately.
+%    \begin{macrocode}
+\newcommand*\MakeSortedPerPage[2][\@ne]{%
+  \pp@makeperpage{#2}\c@spchk@{#1}}
+%    \end{macrocode}
+% \end{macro}
+% All of those must only occur in the preamble since we can't do the
+% initialization of the counter values otherwise.
+%    \begin{macrocode}
+\@onlypreamble\MakePerPage
+\@onlypreamble\MakeSorted
+\@onlypreamble\MakeSortedPerPage
+%    \end{macrocode}
+% \section{Internals}
+%
+% It works in the following manner: The basic work is done through
+% attaching help code to the counter's reset list.  Each counter has
+% an associated absolute id that is counted through continuously and
+% is never reset, thus providing a unique frame of reference.  Sorted
+% and perpage counters work by writing out information to the
+% |.aux| file.
+%
+% The information we maintain for each counter while processing the
+% source file are:
+% \begin{itemize}
+% \item The absolute counter id.
+% \item The last counter value so that we can check whether the
+%   sequence has been interrupted.
+% \item The current scope id.
+% \item Its starting value.
+% \end{itemize}
+%
+% The information written to the file consists of:
+% \begin{itemize}
+% \item The absolute counter id.
+% \item The current scope id.
+% \item The scope's starting value.
+% \item The absolute counter id of a superior counter.
+% \end{itemize}
+%
+% Sorted counters work by writing out the current absolute id and
+% range id into the |.aux| file each time the counter gets incremented.
+% Whenever the counter is changed in a manner different from being
+% incremented, a new counter scope gets started.  Each counter scope
+% has its own independently assigned counter numbers and is associated
+% with its absolute id starting value.  So as each counter is
+% incremented, we write out the triple of current absolute id, counter
+% scope and initial value for the scope.  Scope changes when a value
+% assigned from the file differs from the `natural' value.  When the
+% file is read in, counter movements are tracked.  Each counter that
+% does not have its `natural' value, is having a counter setting
+% recorded.
+%
+% The stuff works by adding a pseudo-reset counter to the counter's
+% dependent counter list.
+%
+% \begin{macro}{\pp@makeperpage}
+%   This does the relevant things for modifying a counter.  It defines
+%   its reset value, it defines the correspoding absolute counter.
+%   The absolute counter serves a double function: it is also used for
+%   assigning numbers while reading the |.aux| file.  For this purpose
+%   it is assigned the initialized values here and in the enddocument
+%   hook (which is called before rereading the |.aux| file and
+%   checking for changed labels), while the counter is reset to zero
+%   at the start of the document.
+%    \begin{macrocode}
+\def\pp@makeperpage#1#2#3{%
+  \global\expandafter\mathchardef\csname c@pp@r@#1\endcsname=#3\relax
+  \global\@namedef{c@pchk@#1}{#2{#1}}%
+  \newcounter{pp@a@#1}%
+  \setcounter{pp@a@#1}{#3}%
+  \addtocounter{pp@a@#1}\m@ne
+  \@addtoreset{pchk@#1}{#1}%
+  \AtBeginDocument{\setcounter{pp@a@#1}\z@}%
+  \edef\next{\noexpand\AtEndDocument
+    {\noexpand\setcounter{pp@a@#1}{%
+        \number\value{pp@a@#1}}}}\next}
+\@onlypreamble\pp@makeperpage
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pp@chkvlist}
+%   Check for an empty vertical list.  If we have one, that is worth
+%   warning about.
+%    \begin{macrocode}
+\def\pp@chkvlist{%
+  \ifcase
+    \ifvmode
+      \ifx\lastnodetype\@undefined
+        \ifdim-\@m\p@=\prevdepth\ifdim\lastskip=\z@\ifnum\lastpenalty=\z@
+          \@ne
+        \fi\fi\fi
+      \else
+        \ifnum\lastnodetype=\m@ne \@ne \fi
+      \fi
+    \fi \z@
+  \or
+    \PackageWarning{perpage}{\string\stepcounter\space probably at start of
+      vertical list:^^JYou might need to use \string\leavevmode\space
+      before it to avoid vertical shifts}%
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pp@fetchctr}
+% \begin{macro}{\theperpage}
+%   This fetches the counter information and puts it into
+%   \cmd{\pp@label}, \cmd{\pp@page} and (globally) into
+%   \cmd{\theperpage}.
+%    \begin{macrocode}
+\def\pp@fetchctr#1{\expandafter\expandafter\expandafter\pp@fetchctrii
+  \csname pp@r@#1@\number\value{pp@a@#1}\endcsname
+  {}{}}
+
+\global\let\theperpage\@empty
+
+\def\pp@fetchctrii#1#2#3{\def\pp@label{#1}%
+  \def\pp@page{#2}%
+  \gdef\theperpage{#3}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% Ok, let's put together all the stuff for the simplest case, counters
+% numbered per page without sorting:
+% \begin{macro}{\c@pchk@}
+%   This is the code buried into to the reset list.  When the reset
+%   list is executed in the context of advancing a counter, we call
+%   something like
+% \begin{verbatim}
+%\global\c@pchk@{countername}\z@
+% \end{verbatim}
+%   since the reset list expected a counter here instead of some
+%   generic command.  That is the reason we start off this command by
+%   giving \cmd{\global} something to chew on.
+%    \begin{macrocode}
+\def\c@pchk@#1{\pp@cl@begin
+%    \end{macrocode}
+%   Now we fetch the page value corresponding to the not yet adjusted
+%   value of the absolute counter to see whether the previous counter
+%   advance happened on the same page.
+%    \begin{macrocode}
+  \pp@fetchctr{#1}\let\next\pp@page
+  \addtocounter{pp@a@#1}\@ne
+  \pp@fetchctr{#1}%
+%    \end{macrocode}
+%   We compare the pages for current and last advance of the counter.
+%   If they differ, we reset the counter to its starting value.  We do
+%   the same if the counter has been reset to zero manually, likely by
+%   being in the reset list of some other counter.
+%    \begin{macrocode}
+  \ifcase\ifx\next\pp@page\else\@ne\fi
+    \ifnum\value{#1}=\z@\@ne\fi\z@
+  \else
+    \setcounter{#1}{\value{pp@r@#1}}%
+  \fi
+  \pp@writectr\pp@pagectr{#1}{\noexpand\theabspage}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pp@writectr}
+%   This is the common ending of all pseudo reset counters.  It writes
+%   out an appropriate command to the |.aux| file with all required
+%   information.  We try to replicate any sentinel kerns or penalties.
+%    \begin{macrocode}
+\def\pp@writectr#1#2#3{\edef\next{%
+    \string#1{#2}{\number\value{pp@a@#2}}{#3}{\noexpand\thepage}}%
+  \pp@chkvlist
+  \dimen@=\lastkern
+  \ifdim\dimen@=\z@ \else \unkern\fi
+  \count@=\lastpenalty
+  \protected@write\@auxout{}{\next}%
+  \ifdim\dimen@=\z@
+    \penalty \ifnum\count@<\@M \@M \else \count@ \fi
+  \else \kern\dimen@\fi
+  \pp@cl@end}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pp@labeldef}
+%   This is a helper macro.
+%    \begin{macrocode}
+\def\pp@labeldef#1#2#3#4#5{\@newl@bel{pp@r@#2}{#3}{{#1}{#4}{#5}}}
+%    \end{macrocode}
+% \end{macro}
+% 
+% \begin{macro}{\pp@pagectr}
+%   This is the workhorse for normal per page counters.  It is called
+%   whenever the |.aux| file is read in and establishes the
+%   appropriate information for each counter advancement in a
+%   pseudolabel.
+%    \begin{macrocode}
+\def\pp@pagectr#1#2#3#4{\@ifundefined{c@pp@a@#1}{}{%
+    \addtocounter{pp@a@#1}\@ne
+    \expandafter\pp@labeldef\expandafter
+      {\number\value{pp@a@#1}}{#1}{#2}{#3}{#4}}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\c@schk@}
+%   This is called for implementing sorted counters.  Sorted counters
+%   maintain a ``count group'', and the values in each count group are
+%   numbered independently from that of other count groups.  Whenever
+%   a counter is found to have been reset, it will start a new count
+%   group.  At the end of document, the count group counters need to
+%   get reset, too, so that the check for changed |.aux| files will
+%   still work.
+%    \begin{macrocode}
+\def\c@schk@#1{\pp@cl@begin
+  \addtocounter{pp@a@#1}\@ne
+  \ifnum\value{#1}=\@ne
+    \expandafter\xdef\csname pp@g@#1\endcsname{\number\value{pp@a@#1}}%
+    \edef\next{\noexpand\AtEndDocument{\global\let
+      \expandafter\noexpand\csname pp@g@#1@\number\value{pp@a@#1}\endcsname
+      \relax}}\next
+  \fi
+  \pp@fetchctr{#1}%
+  \ifx\pp@page\@empty
+  \else \setcounter{#1}{\pp@label}\fi
+  \pp@writectr\pp@spagectr{#1}{\csname pp@g@#1\endcsname}}%
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pp@spagectr}
+%   This is the code advancing the respective value of the appropriate
+%   count group and assigning the label.
+%    \begin{macrocode}
+\def\pp@spagectr#1#2#3#4{\@ifundefined{c@pp@a@#1}{}{%
+    \count@0\csname pp@g@#1@#3\endcsname
+    \advance\count@\@ne
+    \expandafter\xdef\csname pp@g@#1@#3\endcsname{\number\count@}%
+    \expandafter\pp@labeldef\expandafter
+      {\number\count@}{#1}{#2}{#3}{#4}}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\c@spchk@}
+%   And this finally is the counter advance code for sorted counters
+%   per page.  Basically, we just use one count group per page.
+%   Resetting a counter manually will not introduce a new count group,
+%   and it would be hard to decide what to do in case count groups and
+%   page positions overlap.
+%    \begin{macrocode}
+\def\c@spchk@#1{\pp@cl@begin
+  \addtocounter{pp@a@#1}\@ne
+  \pp@fetchctr{#1}%
+  \ifx\pp@page\@empty
+  \else \setcounter{#1}{\pp@label}\fi
+  \pp@writectr\pp@ppagectr{#1}{\noexpand\theabspage}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\pp@ppagectr}
+%    \begin{macrocode}
+\def\pp@ppagectr#1#2#3#4{\@ifundefined{c@pp@a@#1}{}{%
+    \def\next{#3}%
+    \expandafter\ifx\csname pp@page@#1\endcsname\next
+      \addtocounter{pp@a@#1}\@ne
+    \else
+      \setcounter{pp@a@#1}{\value{pp@r@#1}}%
+    \fi
+    \global\expandafter\let\csname pp@page@#1\endcsname\next
+    \expandafter\pp@labeldef\expandafter
+      {\number\value{pp@a@#1}}{#1}{#2}{#3}{#4}}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\@testdef}
+%   \LaTeX's current (2007) definition of this macro causes save stack
+%   overflow.  We fix this by an additional grouping.  Delay to the
+%   beginning of document to keep Babel happy.
+%   \begin{macrocode}
+\AtBeginDocument{%
+  \begingroup
+    \@testdef{}{undefined}{}%
+    \expandafter
+  \endgroup
+  \ifx\@undefined\relax
+    \let\pp@@testdef\@testdef
+    \def\@testdef#1#2#3{{\pp@@testdef{#1}{#2}{#3}%
+        \if@tempswa\aftergroup\@tempswatrue\fi}}%
+  \fi}
+%</style>
+%    \end{macrocode}
+% \end{macro}
+% 
+% \Finale
+% \endinput
+% Local Variables: 
+% mode: doctex
+% TeX-master: "perpage.drv"
+% End: