From d9fe66749d8072f377522910c593df4705a9dc66 Mon Sep 17 00:00:00 2001
From: Karl Berry <karl@freefriends.org>
Date: Mon, 17 Jul 2006 22:56:22 +0000
Subject: bigfoot update (18jul06)

git-svn-id: svn://tug.org/texlive/trunk@1872 c570f23f-e606-0410-a88d-b1316a301751
---
 Master/texmf-dist/source/latex/bigfoot/bigfoot.dtx | 3292 ++++++++++++++++++++
 1 file changed, 3292 insertions(+)
 create mode 100644 Master/texmf-dist/source/latex/bigfoot/bigfoot.dtx

(limited to 'Master/texmf-dist/source/latex/bigfoot/bigfoot.dtx')

diff --git a/Master/texmf-dist/source/latex/bigfoot/bigfoot.dtx b/Master/texmf-dist/source/latex/bigfoot/bigfoot.dtx
new file mode 100644
index 00000000000..feaddf19929
--- /dev/null
+++ b/Master/texmf-dist/source/latex/bigfoot/bigfoot.dtx
@@ -0,0 +1,3292 @@
+% \iffalse
+%%
+%% bigfoot is part of the bigfoot bundle for critical typesetting
+%% Copyright 2004, 05, 06  David Kastrup <dak@gnu.org>
+%%
+% 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{4157}
+% \GetFileInfo{bigfoot.sty}
+% \title{The \texttt{bigfoot} package\\version \fileversion}
+% \date{\filedate}
+% \author{David Kastrup\thanks{dak@gnu.org}}
+% \maketitle
+% Purpose of this package is to provide a one-stop solution to almost
+% all problems related to footnotes.  You can use it as a drop-in
+% replacement of the \texttt{manyfoot} package, but without many of
+% its shortcomings, and quite a few features of its own.  It uses the
+% existing document class layouts for footnotes, so you can usually
+% use it without having to worry about the looks.
+%
+% Features are:
+% \begin{itemize}
+% \item You can specify and use multiple footnote apparatus.
+%   Footnotes for an apparatus lower on the
+%   page\footnoteB{like this one} can be anchored in an
+%   apparatus\footnote{The plural of ``apparatus'' is actually
+%     ``apparatus''\footnoteB{Well, actually ``apparat\=us'' with a
+%       long ``u'', but that's just obvious in spoken Latin.}}
+%   that is higher on the page.
+% \item The last footnote in each apparatus may be broken to the next
+%   page\footnote{This will probably be interesting for footnotes
+%     that contain stuff like math equations\footnoteB+{Like
+%       \begin{equation}
+%         \label{eq:1}
+%         \sum_{k=1}^\infty \frac{1}{k^2} = \frac{\pi^2}{6}
+%       \end{equation}} or lists\footnoteB+{Like
+%       \begin{itemize}
+%       \item This, or
+%       \item this.
+%       \end{itemize}}.}
+%   Any subordinate footnote anchors that get moved to the next page
+%   will take the corresponding footnote with them.
+% \item The order of footnotes in an apparatus is `natural': it starts
+%   with any footnote that may have been broken from the next page,
+%   followed by footnotes from the current page in the order of the
+%   appearance of their footnote
+%   marks.\footnoteB{This footnote appears above notes on notes.}
+%   Where the order of appearance in the document differs from the
+%   order in the source code, you will usually want to use the
+%   \cmd{\MakeSorted} command from the |perpage| package to get the
+%   numbering fixed appropriately.
+% \item Footnotes can be formatted in separate paragraphs, or be run
+%   into a single paragraph.  The choice is made per footnote
+%   apparatus, but can be overridden for single
+%   footnotes.\footnote{Footnotes containing material like display
+%     math\footnoteB{We had this already, right?} or list
+%     environments\footnoteB{And this looks familiar, too.} have to be
+%     done in vertical mode.}
+% \item If footnotes are run into one paragraph, a variety of criteria
+%   makes sure that this formatting is only chosen when it saves
+%   noticeable space and delivers visually attractive results.
+% \item Parameters for footnote formatting can be specified globally,
+%   or separately for each footnote.
+% \item The material in footnotes can contain |\verb|-like material
+%   without problems.\footnote{We wrote \verb+|\verb|-like+ above in
+%     the main text.\footnoteB{Well, this is not so impressive.  But we
+%       wrote \verb/\verb+|\verb|-like+/ in the footnote then.}}
+% \item You can use color in footnotes.  If a footnote gets broken
+%   across pages, the color at the point of the break will get resumed
+%   on the next page.  Actually, the whole color stack will get
+%   reinstated.
+% \end{itemize}
+% As an example of how simple the usage can be, here is the
+% documentation driver for this document:
+%    \begin{macrocode}
+%<*driver>
+\documentclass{ltxdoc}
+\usepackage{bigfoot}
+\usepackage{tabularx}
+\usepackage{hyperref}
+%    \end{macrocode}
+% After loading the packages, we declare two footnote blocks.  One is
+% the default footnote block, another block is called~|B| and is
+% numbered with letters.  The letters start new on each page.  Both
+% footnote blocks default to in-paragraph footnotes.  Since the
+% block~|B| can get entries from both the main text as well as the
+% default footnote block, the entries are not necessarily generated in
+% page order.  So we need to use a sorted counter to fix this (feel
+% free to try what happens when using an unsorted counter).
+%    \begin{macrocode}
+\DeclareNewFootnote[para]{default}
+\DeclareNewFootnote[para]{B}[alph]
+\MakeSortedPerPage{footnoteB}
+%    \end{macrocode}
+% In addition, we add an alternate footnote sequence that can be
+% interspersed with the normal footnotes by use of the
+% \cmd{\footnote'} command which we effectively define here.
+%    \begin{macrocode}
+\newcounter{footalt}
+\def\thefootalt{\fnsymbol{footalt}}
+\MakeSortedPerPage[2]{footalt}
+\WithSuffix\def\footnotedefault'{\refstepcounter{footalt}%
+  \Footnotedefault{\thefootalt}}
+%    \end{macrocode}
+% Actually, that already was all.  We can now start the document.  The
+% following makes sure that we get the full documentation only by
+% compiling the separate driver file:
+%    \begin{macrocode}
+\begin{document}
+\OnlyDescription
+%<driver> \AlsoImplementation
+\DocInput{bigfoot.dtx}
+\end{document}
+%</driver>
+%    \end{macrocode}
+% In order to be useful without additional hassle, the normal footnote
+% level will be called |default|.  If no such style has been defined
+% at the start of the document, it will get defined and used for
+% ordinary footnotes, fixing quite a few problems of \LaTeX's own
+% footnote placement algorithms.
+%
+% Apart from that, usage is very much like that of |manyfoot|, so for
+% the customization possibilities of |bigfoot| with regards to
+% multiple footnote blocks and rules between them, refer to
+% |manyfoot|'s documentation.
+%
+% |bigfoot| contains a lot of bells and whistles for defining your
+% footnote formats and can use different formats for different
+% footnote blocks.  Those expert options are not documented separately
+% yet: look through the code sections to see them explained.
+% \StopEventually{}
+% \section{The implementation}
+% \subsection{Startup code}
+% We declare the package and several compatibility options supposed to
+% make |bigfoot| a drop-in replacement for |manyfoot|.
+%    \begin{macrocode}
+%<*style>
+\NeedsTeXFormat{LaTeX2e}
+\def\FN@next $#1: #2 #3${#2}
+\ProvidesPackage{bigfoot}[\FN@next $Date: 2006/07/15 21:24:56 $
+  \FN@next $Revision: 1.25 $ makes footnotes work]%}
+
+\DeclareOption{para}{\PackageInfo{bigfoot}{Compatibility option `para'
+  has no effect:^^J%
+  Spacing will be guessed from `\string\@makefntext' unless^^J%
+  `\string\@preparefnhtext' is redefined}}
+
+\DeclareOption{para*}{\PackageInfo{bigfoot}{Compatibility option
+    `para*':^^J%
+    Redefining `\string\@preparefnhtext'}%
+  \def\@preparefnhtext{\ifx\@thefnmark\@empty
+    \else\@makefnmark\nobreak\fi}}
+
+\DeclareOption{ruled}{\PassOptionsToPackage{ruled}{manyfoot}}
+%    \end{macrocode}
+% The |verbose| option talks about changed labels at the end of a
+% run.  It is for debugging instable configurations that fail to
+% converge after a number of \TeX\ runs.  The output is probably
+% obscure.
+%    \begin{macrocode}
+\DeclareOption{verbose}{\AtBeginDocument{%
+    \def\@testdef #1#2#3{%
+      \def\reserved@a{#3}%
+      \expandafter \ifx \csname #1@#2\endcsname
+        \reserved@a
+      \else \@tempswatrue
+        \typeout{Changed label #1/#2:
+          \csname #1@#2\endcsname->#3}%
+      \fi}}}
+%    \end{macrocode}
+% The |trace| option is only available if you used |docstrip| while
+% explicitly requesting |trace| functionality.  If you set the |trace|
+% option, the next option specifies a bit map of trace bits.
+%
+% The following bits can be set in tracing:
+% \begin{tabular}{rl}
+%   1&break decisions\\
+%   2&horizontal box building\\
+%   4&allocation stuff\\
+%   8&output routine stuff\\
+%  16&retained and kept boxes
+% \end{tabular}
+%    \begin{macrocode}
+%<trace>\DeclareOption{trace}{%
+%<trace>\DeclareOption*{\ftflags=\CurrentOption\relax
+%<trace>  \DeclareOption*{\OptionNotUsed}}%
+%<trace>  \AtEndOfPackage{\RequirePackage{trace}\relax
+%<trace>  \errorcontextlines\maxdimen
+%<trace>  \showboxdepth4
+%<trace>  \showboxbreadth100
+%<trace>  \tracingonline=\@ne}%
+%<trace>}
+%    \end{macrocode}
+% The |tracepage| option is followed by another option specifying the
+% page to be traced.  If you use it, tracing happens only on the
+% specified page.  Only a single page can be specified.
+%    \begin{macrocode}
+%<trace>\def\FN@tracepage{\c@page}
+%<trace>\DeclareOption{tracepage}{%
+%<trace>  \DeclareOption*{\edef\FN@tracepage{\CurrentOption}%
+%<trace>    \DeclareOption*{\OptionNotUsed}}}
+%<trace>\newcount\ftflags
+%<trace>\def\foottrace#1{\ifnum\numexpr(\ftflags+(#1))/(2*#1)*(2*#1)%
+%<trace>  =\numexpr(\ftflags+3*#1/2)/#1*#1\relax
+%<trace>  f\else t\fi\ifnum\FN@tracepage=\c@page t\else n\fi}
+\ProcessOptions*
+%    \end{macrocode}
+% |hyperref|'s footnote support will just cause trouble.  So if
+% |hyperref| was already loaded or is going to be loaded, we turn off
+% its footnote support.  If you think you know what you are doing, you
+% can use \cmd{\hypersetup} to turn it on again before the start of
+% the document.  Unfortunately, it appears like \cmd{\hypersetup}
+% refuses to be called more than once, so this actually does not work
+% unless you load |hyperref| last.
+%    \begin{macrocode}
+\ifx\hypersetup\@undefined
+  \PassOptionsToPackage{hyperfootnotes=false}{hyperref}
+\else
+  \hypersetup{hyperfootnotes=false}
+\fi
+%    \end{macrocode}
+% We require the |etex| package because
+% \begin{enumerate}
+% \item We need the facilities of the \eTeX\ engine; and where they
+%   are not available, the error messages from not finding the |etex|
+%   package or from loading it into the wrong engine make much more
+%   sense than what would happen otherwise.
+% \item We allocate quite a few registers, and the danger of running
+%   out of them is smaller when the extra registers of \eTeX\ are
+%   taken into account.
+% \end{enumerate}
+% We need the |manyfoot| package to build on.  The |suffix| and
+% |perpage| package are needed for some small stuff.
+%    \begin{macrocode}
+\RequirePackage{etex}
+\RequirePackage{manyfoot}
+\RequirePackage{suffix}
+\RequirePackage{perpage}
+%    \end{macrocode}
+% \subsection{Fixes to the \texttt{manyfoot} package}
+% While those fixes have been submitted once to the author of
+% |manyfoot|, they have not made it into its distribution at the
+% current point of time.  In the interest of stability, it would
+% probably be best just to incorporate the parts from |manyfoot| that
+% get used by |bigfoot|.  This has not yet been done.
+%
+% \begin{macro}{\MFL@reinsout}
+%   We need the appropriate splitting parameters set for the footnote
+%   again.  \cmd{\MFL@realinsert} does that, but it has the disadvantage
+%   that it uses \cmd{\strutbox}, and that may be set to arbitrary
+%   values at the time the output routine is invoked.  |manyfoot|
+%   already has this problem with minipages: the split sizes will be
+%   those of the font at the end of the minipage instead of those at the
+%   time the footnote body was set up.  So we do this here, and see
+%   later for more info about how to do this right:
+%    \begin{macrocode}
+\def\MFL@reinsout#1#2{\ifvoid#2\else
+    \ifnum\count\@currbox>\z@
+      \advance\@pageht \ht#2%
+      \advance\@pageht \skip#2%
+      \advance\@pageht \dp#2%
+    \fi
+    \MFL@realinsert{#2}{\unvbox#2}%
+  \fi
+}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\MFL@reins}
+%   Actually, I don't get the purpose of the following line in the
+%   first place.  But if we do need it for some reason, it is rather
+%   certain that we don't want this empty insert to float.  Use
+%   \cmd{\MFL@realinsert}, or set the floatingpenalty the hard way.
+%    \begin{macrocode}
+\def\MFL@reins#1#2{\ifvoid#2\else\insert#2{\floatingpenalty\@MM}\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\MFL@mpinsert}
+% \begin{macro}{\MFL@minipage}
+%   The structure of the \cmd{\MFL@mpinsert} box is overly
+%   complicated, and it is a bad idea to unpack the boxes put into it
+%   too early: the \cmd{\lastbox} command is pretty inefficient when
+%   the list before it is long due to unpacking.  So we just leave
+%   everything packed in its own boxes, and unpack only at the moment
+%   when we are reinserting.
+%    \begin{macrocode}
+\long\def\MFL@mpinsert#1#2{%
+  \global\setbox#1\vbox{%
+    \unvbox#1%
+    \nointerlineskip
+    \vbox{#2}%
+  }%
+}
+
+\def\MFL@minipage{%
+  \ifinner\else
+    \let\MFL@mpinsertsave\MFL@insert
+    \MFL@reinsert \let\MFL@insert\MFL@mpinsert
+  \fi
+}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\MFL@mpreinsert}
+%   When reinserting, we put all but the last insertion into one
+%   humongous blob.  This is so that the last insertion can be split
+%   by \TeX's paragraph splitting routines.  The footnote types that
+%   |bigfoot| supports will never get split by \TeX, anyhow, but it is
+%   conceivable that other extension packages for manyfoot work
+%   differently.  There is one difference, though: we let a slave mark
+%   escape into the main vertical list.
+%    \begin{macrocode}
+\def\MFL@mpreinsert#1#2{%
+  \ifvoid#2\else
+    \setbox\@tempboxa\vbox\bgroup\unvbox#2%
+      \global\setbox#2\lastbox
+      \setbox\z@\lastbox
+      \ifvoid\z@
+        \egroup
+        \setbox\z@\box#2%
+      \else
+        \MFL@removevboxes \unvbox\z@
+        \egroup
+        \setbox\z@\box#2%
+        \MFL@mpinsertsave#2{\unvbox\@tempboxa}%
+      \fi
+    \ifvoid\z@\else
+      \MFL@mpinsertsave#2{\unvbox\z@}%
+    \fi
+    \marks\FN@slave{\number\FN@id}%
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\MFL@removevboxes}
+%   The trick is like with \cmd{\removehboxes} in the \TeX book's
+%   appendix~D.
+%    \begin{macrocode}
+\def\MFL@removevboxes{{\setbox\z@\lastbox
+    \ifvbox\z@ \MFL@removevboxes \unvbox\z@\fi}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\NCC@makefnmark}
+%   This provides the command in case it is not present (some versions
+%   did not have it).
+%    \begin{macrocode}
+\ifx\NCC@makemark\@undefined
+  \ifx\NCC@makefnmark\@undefined \else
+    \def\NCC@makemark{\NCC@makefnmark}
+  \fi
+\fi
+%    \end{macrocode}
+% \end{macro}
+%
+% While the above operations actually were fixes to |manyfoot|, now we
+% actually patch it for our own purposes.  When allocating a new
+% footnote, we set its maximum dimension to \cmd{\maxdimen} (since no
+% hard limit makes sense, given that we recalculate all respective
+% sizes at output time) and allocate a cache box to go with it.  We
+% also add the insertion to the list of insertions in
+% \cmd{\FN@nestlist}.
+% \begin{macro}{\MFL@startplain}
+% \begin{macro}{\MFL@startpara}
+%    \begin{macrocode}
+\def\MFL@startplain#1{\global\dimen#1\maxdimen
+  \@cons\FN@nestlist{{}#1}%
+  \expandafter\expandafter\expandafter\newbox\FN@cache#1}
+
+\let\MFL@startpara\MFL@startplain
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\RestyleFootnote}
+%   This macro gets two arguments: a footnote \meta{type}, and the
+%   style to be used for it.  It works by redefining the corresponding
+%   |Footnotetext|\meta{type} macro.
+%    \begin{macrocode}
+\def\RestyleFootnote#1#2{\expandafter\xdef
+  \csname Footnotetext#1\endcsname{\expandafter
+    \noexpand\csname MFL@fnote#2\endcsname{\csname footins#1\endcsname}}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@stripfootins}
+% \begin{macro}{\FN@restylefootnote}
+%   We need the same kind of functionality for a footnote specified by
+%   its footnote insertion.  So we strip the footnote \meta{type} from
+%   the insertion macro name.  Kind of ugly.
+%    \begin{macrocode}
+\expandafter\def\expandafter\FN@stripfootins\string\footins{}
+
+\def\FN@restylefootnote#1#2{{\edef\next{%
+      \noexpand\RestyleFootnote{\expandafter\FN@stripfootins
+        \string#1}{#2}}\next}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Dealing with footnote-specific code}
+% The formatting of footnotes is determined by macros such as
+% \cmd{\@makefntext}.  For several blocks of footnotes, we might want
+% to have several different ways for formatting them.  Whenever this
+% is the case, we call them with
+% \begin{quote}
+%   |\FN@specific|\marg{insert\#}\marg{macroname}
+% \end{quote}
+% This will use the default \meta{macroname} unless a special macro has
+% been defined with something like
+% \begin{quote}
+%   |\FootnoteSpecific\marg{type}|\def|\meta{macroname}\dots
+% \end{quote}
+% A number of other defining commands and constructs are available:
+% those are pretty much like the ones for the \cmd{\WithSuffix} command
+% implemented by the |suffix| package.
+% \begin{macro}{\FN@specific}
+%   We use |\romannumeral| here just for the purpose of sustaining
+%   expansion.  It expands to nothing when followed by |\z@|
+%   eventually.  Thus expanding the expansion of \cmd{\FN@specific}
+%   again delivers the (unexpanded) final token to use.
+%    \begin{macrocode}
+\def\FN@specific#1#2{\romannumeral
+  \ifcsname FN\string#2\number#1\endcsname
+  \expandafter
+    \z@\csname FN\string#2\number#1\expandafter\endcsname
+  \else\expandafter\z@
+    \expandafter#2\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FootnoteSpecific}
+% \begin{macro}{\FN@specific@ii}
+%   This is all a bit muddy, but quite similar to what the |suffix|
+%   package does, so you might want to look there for the explanation.
+%    \begin{macrocode}
+\def\FootnoteSpecific#1{\count@\csname footins#1\endcsname\toks@{}%
+  \FN@specific@ii}
+
+\long\def\FN@specific@ii#1#2{\toks@\expandafter{\the\toks@#1}%
+  \the\expandafter\toks@
+  \csname FN\string#2\number\count@\endcsname}
+
+\WithSuffix\def\FN@specific@ii\long{\toks@\expandafter
+  {\the\toks@\long}\FN@specific@ii}
+
+\WithSuffix\def\FN@specific@ii\global{\toks@\expandafter
+  {\the\toks@\global}\FN@specific@ii}
+
+\WithSuffix\def\FN@specific@ii\expandafter{\expandafter
+  \FN@specific@ii\expandafter}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsection{Putting footnotes into insertions}
+% \subsubsection{Dealing with Ids}
+%   Since we have to store additional information for each footnote as
+%   long as it is not yet typeset, we allocate and deallocate numeric
+%   `id's on an as-needed base, since we do not want to store this
+%   sort of information indefinitely, with a large toll on hash space.
+%   So we work with indirect ids, where the unique ids are just
+%   referenced indirectly.  We do this with `slots'.
+% \begin{macro}{\FN@slotxdef}
+% \begin{macro}{\FN@slotget}
+%   New slots are assigned values with \cmd{\FN@slotxdef}, which can
+%   be retrieved again with \cmd{\FN@slotget}.
+%    \begin{macrocode}
+\def\FN@slotxdef#1{%
+  \global\expandafter\xdef\csname FN@slot#1\endcsname}
+
+\def\FN@slotget#1{\csname FN@slot#1\endcsname}
+%<trace>\def\FN@slotget#1{%
+%<trace>  \expandafter\FN@slotgetii\expandafter
+%<trace>     \FN@slotfreelist\expandafter
+%<trace>     {\number\number#1}}
+%<trace>\def\FN@slotgetii#1#2{%
+%<trace>  \ifx#1\@empty \csname FN@slot#2\endcsname\else
+%<trace>    \ifnum#1=#2 \errmessage{Use after freed: #1}\else
+%<trace>       \expandafter\FN@slotgetii
+%<trace>         \csname FN@slot#1\endcsname{#2}\fi\fi}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\FN@slotfreelist}
+% \begin{macro}{\FN@nextslot}
+%   \cmd{\FN@slotfreelist} point to the first already allocated
+%   available id to be reused.  If it is empty, none exist.  In that
+%   case, \cmd{FN@nextslot} contains the next slot number to use.
+%    \begin{macrocode}
+\def\FN@slotfreelist{}
+\def\FN@nextslot{1}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\FN@newslot}
+%   This allocates a new slot by setting the given macro to a
+%   currently unused slot number in decimal form.  If there is
+%   something left in the freelist, it is assigned, otherwise a new
+%   slot gets allocated.
+%    \begin{macrocode}
+\def\FN@newslot#1{%
+  \ifx\FN@slotfreelist\@empty
+    \edef#1{\FN@nextslot}%
+    \xdef\FN@nextslot{\number\numexpr \FN@nextslot+\@ne}%
+  \else
+    \let#1\FN@slotfreelist
+    \xdef\FN@slotfreelist{\csname FN@slot\FN@slotfreelist\endcsname}%
+  \fi
+%<trace>  \if\foottrace4\message{^^JAllocated #1^^J}\fi
+}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@freeslot}
+%   This frees a given slot (by number) again by adding it to the
+%   freelist.
+%    \begin{macrocode}
+\def\FN@freeslot#1{%
+%<trace>  \if\foottrace4\message{^^JFreeing #1^^J}\fi
+  \global\expandafter\let\csname FN@slot#1\endcsname=\FN@slotfreelist
+  \xdef\FN@slotfreelist{#1}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Dealing with footnote stacks}
+% Footnote stacks are used for paired footnotes that refer to a text
+% range instead of a single text point.  For example, you can use
+% something like
+% \begin{verbatim}
+% Text \var<{was there}is here\var>
+% \end{verbatim}
+% To have a text variant ``was there'' for the original passage ``is
+% here'', and mark it, say, as ``\textsuperscript{a}is
+% here\textsuperscript{\textsl{a}}'' by employing the |suffix| package
+% suitably.  This would anchor the footnote at the start of the
+% passage.  It would also be imaginable to implement the syntax
+% \begin{verbatim}
+% Text \var<is here\var>{was there}
+% \end{verbatim}
+% for anchoring it at the end of the given passage.
+%    \begin{macrocode}
+\global\let\FN@stacklist\@empty
+%    \end{macrocode}
+% \begin{macro}{\DefineFootnoteStack}
+%   This command is used for defining a footnote stack.  It gets a
+%   single argument which is the name of the stack and should consist
+%   just of ordinary character tokens.
+%    \begin{macrocode}
+\def\DefineFootnoteStack#1{%
+  \global\expandafter\let\csname FN@stack@#1\endcsname\@empty
+  \@cons\FN@stacklist{{#1}}%
+}
+%    \end{macrocode}
+% \end{macro}
+% At the end of the document, all stacks are checked to make sure they
+% have been used up completely.
+%    \begin{macrocode}
+\AtEndDocument{\FN@checkstacklist}
+
+\def\FN@checkstacklist{{\let\@elt\FN@checkstack
+  \FN@stacklist}}
+
+\def\FN@checkstack#1{{\let\@elt\FN@checkstackentry
+    \csname FN@stack#1@\endcsname}}
+
+\def\FN@checkstackentry#1#2#3{%
+  \PackageError{bigfoot}{Unfinished #1 #2 from line #3}%
+  {The specified footnote range is uncomplete}}
+%    \end{macrocode}
+% \begin{macro}{\PushFootnoteMark}
+%   This gets one argument, the name of the footnote stack.  It pushes
+%   the current footnote mark name stored in \cmd{\@thefnmark} onto
+%   the footnote stack.
+%    \begin{macrocode}
+\def\PushFootnoteMark#1{{\let\@elt\relax
+  \expandafter\unrestored@protected@xdef \csname FN@stack@#1\endcsname
+  {\@elt{#1}{\@thefnmark}{\number\inputlineno}\csname
+  FN@stack@#1\endcsname}}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\PopFootnoteMark}
+%   This gets one argument, the name of the footnote stack.  It pops
+%   the value of \cmd{\@thefnmark} from the named footnote stack.
+%    \begin{macrocode}
+\def\PopFootnoteMark#1{\expandafter
+  \ifx\csname FN@stack@#1\endcsname\@empty
+    \PackageError{bigfoot}{Empty footnote stack #1}%
+    {The specified footnote type has no uncompleted range}%
+  \else
+  {\let\@elt\FN@firstpop
+    \iffalse{\fi\csname FN@stack@#1\endcsname}}\fi}
+%    \end{macrocode}
+% \end{macro}
+%    \begin{macrocode}
+\def\FN@firstpop#1#2#3{\protected@xdef\@thefnmark{#2}%
+  \let\@elt\relax
+  \expandafter\protected@xdef\csname FN@stack@#1\endcsname{%
+    \iffalse}\fi}
+%    \end{macrocode}
+%
+%
+%\subsubsection{The works}
+%
+% \begin{macro}{\FN@cache}
+%   Cacheboxes cache the typeset forms of the insertion boxes for a
+%   certain configuration of footnotes.
+%    \begin{macrocode}
+\def\FN@cache#1{\csname FN@cache\number#1\endcsname}
+%    \end{macrocode}
+% \end{macro}
+% \cmd{\FN@sortlist} takes the current vertical list and sorts the
+% contained boxes according to their width (which is supposed to
+% contain the sort key).
+%
+% The algorithm is a pretty straightforward insertion sort with
+% $O(n^2)$~steps.  This is the best one can hope for without
+% comparisons across non-adjacent list elements.  For presorted lists,
+% the performance will be $O(n)$, and that's what we expect to see for
+% simple cases (and when there are no sortkeys yet).  Any negative
+% width will certainly hang the algorithm.
+%
+% It also happens that \TeX\ has a hardwired limit for grouping levels
+% that hits at 255.  Oops.  We better not have a few hundred footnotes
+% in a single block on one page\dots
+%    \begin{macrocode}
+\def\FN@sortlist{{%
+  \setbox\z@\lastbox
+  \ifvoid\z@ \else \FN@sortlist\FN@sortlistii \fi}}
+
+\def\FN@sortlistii{%
+  \setbox\tw@\lastbox
+  \ifvoid\tw@\else
+  \ifdim\wd\tw@<\wd\z@ {\FN@sortlistii}%
+  \fi\nointerlineskip\box\tw@\fi\nointerlineskip\box\z@}
+%    \end{macrocode}
+% \begin{macro}{\FN@sortinsert}
+%   This function is an \cmd{\@elt} function that will sort the given
+%   insertion if it is non-empty and if there is no cache box present
+%   (which would imply that the insertion had already been sorted
+%   previously).
+%    \begin{macrocode}
+\def\FN@sortinsert#1#2{\ifvoid\FN@cache#2%
+  \ifvoid#2\else\global\setbox#2\vbox{\unvbox#2%
+    \FN@sortlist}\fi\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@maybeinvalidatecache}
+%   This is called after pulling in additional material from the
+%   page.  If the material added an insertion, the cache is junk and
+%   must be regenerated.
+%    \begin{macrocode}
+\def\FN@maybeinvalidatecache#1#2{%
+  \ifvoid#2\else\global\setbox\FN@cache#2=\box\voidb@x\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@regeneratecache}
+%   This unconditionally regenerates one cache box.  The structure of
+%   a cache box is basically a list of vertical boxes.  All but the
+%   last such box are packed into a single vertical box which is then
+%   followed by the last vertical box.
+%    \begin{macrocode}
+\def\FN@regeneratecache#1#2{%
+   \global\setbox\FN@cache#2=%
+   \ifvoid#2%
+     \box\voidb@x
+   \else
+     \vbox{\vbox{\unvcopy#2%
+         \setbox\z@\lastbox
+         \def\FN@masterinsert{#2}%
+         \FN@assembleboxes
+         \global\setbox\FN@cache#2\box\z@}%
+       \nointerlineskip \box\FN@cache#2}%
+    \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@mayberegeneratecache}
+%   This regenerates the cache in case the cache box has been voided
+%   in order to mark it as invalid.
+%    \begin{macrocode}
+\def\FN@mayberegeneratecache#1#2{%
+  \ifvoid\FN@cache#2%
+    \FN@regeneratecache{}#2%
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@cachesize}
+%   This calculates the size impact of a cache box on the current page
+%   as a term to be added into a \cmd{\glueexpr}-type of expression.
+%    \begin{macrocode}
+\def\FN@cachesize#1#2{%
+  \ifvoid\FN@cache#2%
+  \else
+    +\skip#2+(\ht\FN@cache#2+\dp\FN@cache#2)*\count#2/\@m
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@clearcache}
+%   This just completely voids a cache register.
+%    \begin{macrocode}
+\def\FN@clearcache#1#2{%
+  \global\setbox\FN@cache#2=\box\voidb@x}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@makefnvtext}
+%   Ok, this is one of the parts putting together footnotes in para
+%   mode.  The footnotes themselves have already been formatted into
+%   hboxes (placed there with \cmd{\@preparefnhtext} in order to cater
+%   for proper indentation).  \cmd{\@makefnvtext} then formats a
+%   single footnote block from horizontal mode pieces (vertical mode
+%   pieces are kept as-is).
+%   This takes text and typesets it in a single block.  To get correct
+%   indentation, it breaks before the first footnote and adjusts the
+%   clubpenalties to move them to one line lower effectively.
+%   \cmd{\@makefnvtext} is called in vertical mode, and its argument
+%   is typeset in horizontal mode right after a break, inside of
+%   \cmd{\@makefntext}.
+%    \begin{macrocode}
+\def\@makefnvtext#1{%
+  \FN@specific\FN@masterinsert\@makefntext{%
+    \clubpenalties\tw@\@MM\clubpenalty
+    \vadjust{\nobreak\vskip-\baselineskip}\nobreak\hfill\break#1}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\@preparefnhtext}
+%   This creates appropriate skips to be put before the horizontal
+%   material to make the indentation correct with a breakpoint before
+%   the footnote as well as when in run-in text.  This is run once at
+%   the start of each horizontal mode footnote when it is first being
+%   typeset, in horizontal mode.
+%    \begin{macrocode}
+\ifx\@preparefnhtext\@undefined
+\def\@preparefnhtext{{%
+  \setbox\z@\vbox{\FN@specific\FN@masterinsert\@makefntext{%
+      \unskip\unpenalty\setbox\z@\lastbox
+      \dimen@
+        \ifnum\parshape>\z@
+          \dimexpr\parshapeindent\tw@-\parshapeindent\@ne\relax
+        \else \ifnum\hangafter=\@ne\hangindent \else
+          \ifnum\hangafter=\m@ne -\hangindent
+          \else \z@ \fi\fi\fi
+      \dimen@ii\dimen@
+      \ifhbox\z@ \advance\dimen@-\wd\z@
+        \setbox\z@\hbox{\unhbox\z@}%
+        \advance\dimen@\wd\z@
+      \fi
+      \xdef\FN@tempinfo{\hskip\the\dimen@
+        \vadjust{}\nobreak\hskip-\the\dimen@ii\relax}}}}%
+  \FN@tempinfo}
+\fi
+%    \end{macrocode}
+% Now we have in |\FN@tempinfo| the excess width of the label we don't
+% want to preserve when doing in-paragraph footnote setting.  A
+% sequence of glue before a label now has to consist of stuff that
+% vanishes at a breakpoint, followed by stuff that remains.  We have
+% to have two behaviors for the contents: behavior one is
+% justification at the start of a line, behavior two is justification
+% in the line.  When we are at the start of the line, preceding
+% interword space disappears swallowed and so the natural criterion
+% for distinguishing those cases is this initial line break.  This
+% means that we can't avoid articifially adding a line break at the
+% start of such a box.  We will back up its height again.  Some
+% packages specify a |\hangindent| (I~know of no examples where they
+% would actually set |\hangafter| to a value different from its
+% default of~1, or set |\hangindent| to a negative value which would
+% affect the right margin): due to our artifical line at the top, the
+% indent will actually be active for the first line already.  We back
+% it out of the actual labels happening at the start of the line.
+% Two-line parshapes have the same effect: the first line is not
+% actually used, and we put the relevant info for the first line into
+% the label.  Different right indentation for the first line is
+% something we can't simulate, but again, it should occur rarely.
+% When |\parshape| is active, |\hangindent| is ignored.
+% \end{macro}
+%    \begin{macrocode}
+\def\@makefnstartbox{%
+  \reset@font\footnotesize
+  \hsize\MFL@columnwidth \@parboxrestore
+  \interlinepenalty\FN@specific\FN@masterinsert\interfootnotelinepenalty
+  \widowpenalty\FN@specific\FN@masterinsert\footnotewidowpenalty
+  \clubpenalty\FN@specific\FN@masterinsert\footnoteclubpenalty
+  \advance\linepenalty500\relax}
+
+\def\@makefnendbox{%
+  \widowpenalty\FN@specific\FN@masterinsert\finalfootnotewidowpenalty}
+
+\newcount\footnotewidowpenalty
+\footnotewidowpenalty=250
+\newcount\footnoteclubpenalty
+\footnoteclubpenalty=250
+\newcount\finalfootnotewidowpenalty
+\finalfootnotewidowpenalty=4000
+%    \end{macrocode}
+% \begin{macro}{\@makefnvbox}
+% This is the formatting code for a vertical mode footnote box.  It
+% uses \cmd{\@makefnstartbox} for setting up the initial widow/club
+% penalties, and \cmd{\@makefnendbox} for preparing the final end.  It
+% results in a vbox, but its argument, a stream of horizontal and
+% vertical material, is typeset in
+%    \begin{macrocode}
+\ifx\@makefnvbox\@undefined
+  \def\@makefnvbox#1{\vbox{%
+      \@makefnstartbox
+      \clubpenalties\tw@\@MM\clubpenalty
+      \let\@thefnmark\@empty
+      \FN@specific\FN@masterinsert\@makefntext{\rule\z@\footnotesep
+        \nobreak
+        #1\@finalstrut\strutbox
+      \@makefnendbox}}}
+\fi
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\hfootfraction}
+% \begin{macro}{\vtypefraction}
+%   Those parameters govern when a footnote block is going to be set
+%   completely in vertical mode.  If a footnote block does not shrink
+%   to less than \cmd{\hfootfraction} its size when using in-paragraph
+%   notes and, has at least \cmd{\vtypefraction} of forcedly vertical
+%   footnotes (specified as purely vertical, or vertical because of
+%   being large), it is set entirely in vertical mode.
+%
+%   In addition, the ratio of purely vertical footnotes must not fall
+%   below \cmd{\vtypefraction}.
+%    \begin{macrocode}
+\def\hfootfraction{0.9}
+\def\vtypefraction{0.6}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\FN@assembleboxes}
+%   This will produce the finished product, by generating all boxes
+%   and concatenating them except for the last vbox.  It is assumed
+%   that have already set |\box\z@| to |\lastbox| before calling this
+%   routine (or, more likely, have already assembled and split the
+%   last box).  The last, not yet unpacked |\vbox| is left in
+%   |\box\z@| on return.  The original id of the last box of a block
+%   is properly transferred to it.
+%
+%   The last box might have come about by joining several horizontal
+%   boxes, so splitting it might separate footnotes.  We deal with
+%   that problem at a different point of time by checking the
+%   respective Ids when breaking a vbox into pieces: if the split
+%   piece does not contain the last footnote beginning, we switch to a
+%   slow motion decomposal.  \cmd{\FN@assembleboxes} is supposed to be
+%   entered and exited in vertical mode.
+%    \begin{macrocode}
+\def\FN@assembleboxes{%
+%<trace> \ifhmode \PackageError{bigfoot}{Unexpected hmode}{}\fi
+  \ifhbox\z@
+    \dimen@\dp\z@
+%<trace> \MFL@checksinglebox\z@\z@{}{}%
+    \dimen@ii\z@
+    \setbox\tw@\box\voidb@x
+    \loop \advance\dimen@ii\dimexpr\ht\z@+\dp\z@\relax
+      \setbox\tw@\hbox{\box\z@\unhbox\tw@}%
+      \setbox\z@\lastbox
+    \ifhbox\z@
+    \repeat
+    {\FN@assembleboxes\nointerlineskip\unvbox\z@}%
+%    \end{macrocode}
+% At this point of time, |\box\tw@| contains a plain hbox with nothing
+% but the unadorned hboxes in horizontal mode to be joined into one
+% footnote block.  All preceding footnote blocks have been emptied
+% into the current vertical list.  We put the |\unvbox| operations in
+% a group so that the paragraph shapes will not get reset over the
+% break.
+%    \begin{macrocode}
+    \global\setbox\FN@tempbox\copy\tw@
+    \setbox\z@\@makefnvbox{%
+      {\unhbox\FN@tempbox}%
+      \setbox\z@\lastbox\FN@joinhboxes}%
+    \ifdim\FN@vfound>\dimexpr\vtypefraction\p@*\FN@found\relax
+      \ifdim\dimexpr \ht\z@+\dp\z@>\hfootfraction\dimen@ii
+        \global\setbox\FN@tempbox\box\tw@
+        \setbox\z@\@makefnvbox{\let\@makefnbreak\FN@pseudofillbreak
+            {\unhbox\FN@tempbox}\setbox\z@\lastbox\FN@joinhboxes}%
+      \fi
+    \fi
+    \setbox\tw@\box\voidb@x
+    \ht\z@\dimexpr \ht\z@+\dp\z@-\dimen@\relax
+    \dp\z@\dimen@
+%<trace>  \MFL@checksinglebox\z@\z@{}{}%
+  \else
+    \ifvbox\z@
+%<trace>  \MFL@checksinglebox\z@\z@{}{}%
+      {\setbox\z@\lastbox
+      \FN@assembleboxes\nointerlineskip\unvbox\z@}%
+    \fi
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% Ok, now follow a lot of fuzzy calculation routines.  When we are
+% considering truth values, |\p@| (1pt) corresponds to a value of
+% ``true'', and |\z@| corresponds to ``false''.
+% \begin{macro}{\FN@fuzzyeval}
+%   This calculates a ratio, something with which you multiply.  The
+%   first two arguments of the function define an interval, and the
+%   third argument is a value in that interval.  If |#3| is equal to
+%   |#1|, the resulting ratio is~0, if the |#3| is equal to |#2|, the
+%   resulting ratio is~1.  Values in between are linearly
+%   interpolated.  Values outside of the interval are mapped to 0
+%   and~1.  If all three values are equal (hardly useful), 1 is
+%   returned.
+%    \begin{macrocode}
+\def\FN@fuzzyeval#1#2#3{%
+  \ifdim\dimexpr(#3)<\dimexpr(#2)\relax
+    \ifdim\dimexpr(#3)>\dimexpr(#1)\relax
+      *(\dimexpr(#3)-(#1))%
+      /(\dimexpr(#2)-(#1))%
+    \else *\z@
+    \fi
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@fuzzyor}
+%   This returns probabilistic \textsc{or}:
+%   \[(|#1|+|#2|-|#1|\cdot|#2|)\]
+%    \begin{macrocode}
+\def\FN@fuzzyor#1#2{(\p@-(\p@-(#1))*(\dimexpr\p@-(#2))/\p@)}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@magicclue}
+% Ok, so here is the magic glue calculator.  |#1| and~|#2| give the
+% range over which the preceding line changes from `short' to `long'.
+% |#3| and |#4| give the range over which the current line changes
+% from `short' to `long'.  Both are combined with a probabilistic or
+% function, and then a penalty is chosen which ranges from |#5|
+% to~|#6| for short to long.
+%    \begin{macrocode}
+\def\FN@magicglue#1#2#3#4#5#6{%
+%<trace> \if\foottrace2\traceon\fi
+  \dimen@\dimexpr\p@\FN@fuzzyeval{#1}{#2}\FN@lasthsize\relax
+  \dimen@ii\dimexpr\p@\FN@fuzzyeval{#3}{#4}{\ht\z@+\dp\z@}\relax
+  \dimen@\dimexpr\FN@fuzzyor\dimen@\dimen@ii
+  \count@\numexpr((#6)-(#5))*\dimen@/\p@+(#5)\relax
+  \xdef\FN@vfound{\the\dimexpr\FN@vfound+\dimen@}%
+  \ifnum\count@>-\@M
+    \penalty\count@
+    \hskip\glueexpr -\parfillskip+1em minus 0.5em\relax
+  \else
+    \FN@pseudobreak
+  \fi
+  \xdef\FN@found{\number\numexpr\FN@found+\@ne}%
+}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@pseudobreak}
+%   This ends a line, but without introducing parskip and similar.  It
+%   also `breaks in' the next line to get proper indentation.  The
+%   main difference with regard to \cmd{\break} is that this restarts
+%   the reckoning of line numbers for the sake of \cmd{\clubpenalty}
+%   calculation.
+%    \begin{macrocode}
+\def\FN@pseudobreak{%
+    {\parskip\z@skip\parfillskip\z@skip\parindent\z@\vadjust{}\par\noindent
+      \vadjust{\nobreak\vskip-\baselineskip}\nobreak\hfill\break}}      
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@pseudofillbreak}
+%   This is basically just for separating paragraphs by force.
+%    \begin{macrocode}
+\def\FN@pseudofillbreak{\nobreak\hskip\parfillskip\FN@pseudobreak}
+%    \end{macrocode}
+%   
+% \end{macro}
+% \begin{macro}{\@makefnbreak}
+%   This calculates the glue for the standard horizontal footnotes.
+%    \begin{macrocode}
+\def\@makefnbreak{\FN@magicglue {\footnotesep+\dp\strutbox}%
+  {\footnotesep+\dp\strutbox+\baselineskip}%
+  {\footnotesep+\dp\strutbox+0.5\baselineskip}%
+  {\footnotesep+\dp\strutbox+2\baselineskip}{-200}{-12000}}
+%    \end{macrocode}
+% \end{macro}
+% \cmd{\FN@joinhboxes} is called with box~0 set to the next box to be
+% appended to the current list (all preceding hboxes on the current
+% vertical list will have to go in front).  \cmd{\FN@joinhboxes} is
+% entered in vertical mode, and will be exited in horizontal mode.
+%    \begin{macrocode}
+\def\FN@joinhboxes{%
+%<trace> \ifvmode \errmessage{Unexpected vertical mode.}\fi
+  \begingroup\setbox\z@\lastbox
+    \ifhbox\z@ \FN@joinhboxes
+%<trace> \ifvmode \errmessage{Unexpected vertical mode.}\fi
+      \endgroup
+      \nobreak\hskip\parfillskip
+      \@makefnbreak
+    \else
+%<trace> \ifvbox\z@ \errmessage{Unexpected vbox.}\fi
+      \endgroup
+      \vadjust{\nobreak\vskip-\baselineskip}\nobreak\hfill\break
+      \xdef\FN@vfound{\z@}%
+      \xdef\FN@found{\z@}%
+    \fi
+  \xdef\FN@lasthsize{\the\dimexpr \ht\z@ +\dp\z@}%
+  \unhbox\z@}
+%    \end{macrocode}
+% \begin{macro}{\FN@par}
+% \begin{macro}{\FN@noindent}
+% \begin{macro}{\FN@indent}
+%   In-paragraph footnotes are collected in horizontal mode.  So
+%   |\par|, \cmd{\noindent} and \cmd{\indent} simply don't work.  We
+%   replace them with something having the same effect when the boxes
+%   get unhboxed.  Note that this does not admit the tracking of
+%   club/widow penalties: in a later version, it should get replaced
+%   by something that actually allows for separate paragraphs.  One
+%   possibility would be to replace the current single hbox for an
+%   in-paragraph footnote by an hbox of hboxes and unbox all of them
+%   in separate paragraphs.  But that glosses over the fact that a
+%   multi-paragraph footnote does not make sense in anything but
+%   vertical mode.  So a saner way would probably be to close off the
+%   hbox altogether and reinsert it into a vbox, restarting the whole
+%   footnote in vertical mode.  Both of those approaches would require
+%   that no groups have been opened since the start of the footnote by
+%   the time |\par| gets called.  The below pseudosolution at least
+%   has the advantage of not depending on the grouping structure at
+%   all.
+%    \begin{macrocode}
+\def\FN@par{\unskip\nobreak\hskip\parfillskip
+  \vadjust{\vskip\parskip}\break\null\kern\parindent\ignorespaces}
+\def\FN@noindent{\unkern}
+\def\FN@indent{\unkern{\setbox\z@\null\wd\z@\parindent\box\z@}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\MFL@fnoteplain}
+% \begin{macro}{\MFL@fnotepara}
+%   We redefine |manyfoot|'s basic footnote calls to use our own,
+%   versatile variant.
+%    \begin{macrocode}
+\def\MFL@fnoteplain{\FN@fnotenested{plain}}
+\def\MFL@fnotepara{\FN@fnotenested{para}}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\FN@fnotenested}
+%   This is somewhat contorted: we want |\footnote+| to be in |plain|
+%   style and |\footnote-| in |para| style regardless of the current
+%   footnote style.  Adding a second |+| or |-| after the first will
+%   actually restyle all footnotes coming afterwards appropriately.
+%   This should work for all footnote commands getting footnote text.
+%    \begin{macrocode}
+\def\FN@fnotenested#1#2#3{%
+  \edef\reserved@d{#1}%
+  \FN@checkvariant{\edef\reserved@d}{%
+    \FN@checkvariant{\FN@restylefootnote{#2}}%
+    {\csname FN@fnote\reserved@d\endcsname{#2}{#3}}}}
+
+\def\FN@checkvariant#1#2{\def\reserved@a{#1}%
+  \def\reserved@b{#2}%
+  \futurelet\reserved@c\FN@checkvariantii}
+
+\def\FN@checkvariantii{%
+  \ifx\reserved@c+%
+    \reserved@a{plain}\expandafter\@firstoftwo
+  \else\ifx\reserved@c-%
+    \reserved@a{para}\expandafter\expandafter\expandafter
+    \@firstoftwo
+  \fi\fi
+  \reserved@b}
+%    \end{macrocode}
+% \end{macro}
+% In order to be able to sort footnotes according to the order of
+% their reference points, we use a sorted counter.
+%    \begin{macrocode}
+\newcounter{FN@totalid}
+\MakeSorted{FN@totalid}
+%    \end{macrocode}
+% \begin{macro}{\FN@fnoteplain}
+% \begin{macro}{\FN@fnotepara}
+%   The actual commands are easy enough:
+%    \begin{macrocode}
+\def\FN@fnoteplain{\FN@fnotecommon\vbox}
+\def\FN@fnotepara{\FN@fnotecommon\hbox}
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\FN@masterinsert}
+%   This contains the insert number of the insert where the footnote
+%   mark appears.  If it appears in the main text, 255~will be used.
+%    \begin{macrocode}
+\def\FN@masterinsert{\@cclv}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@id}
+% \begin{macro}{\FN@master}
+% \begin{macro}{\FN@slave}
+%   Here is the deal with master and slave ids: each footnote has a
+%   unique master id.  This master id is larger by one than the last
+%   id of its subordinate footnotes.  It is recorded in the mark
+%   \cmd{\FN@master} in the footnote box at the start itself, although
+%   with an indirection through the \cmd{\FN@newslot} mechanism since
+%   the actual id can only become known after all subfootnotes have
+%   been typeset.  The same id is recorded in \cmd{\FN@slave} at the
+%   ultimate end of the footnote.
+%
+%   At the point where a \cmd{\FN@master} mark is placed, a default
+%   \cmd{\FN@slave} mark is placed also with an id that is one less
+%   than the smallest id generated from a footnote that is a
+%   `descendent' of the current one.  This makes it possible to
+%   distinguish any split off subordinate footnotes.  It must be noted
+%   that this sentinel slave id will be the valid id of a completely
+%   unrelated footnote!  Since the value is only used for determining
+%   one end of an \emph{open} interval of excluded ids, this is no
+%   problem.  All subordinate footnotes are numbered sequentially in
+%   the order of \emph{completion}, so that any subordinate footnotes
+%   have lower ids than their master.
+%    \begin{macrocode}
+\newcount\FN@id
+\FN@id\@ne
+\newmarks\FN@master
+\newmarks\FN@slave
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\FN@errorstack}
+%   This records the history of nested footnotes in order to deliver
+%   more useful error messages.
+%    \begin{macrocode}
+\let\FN@errorstack\@empty
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@fnotecommon}
+%   Well, this is the work horse if the footnote macro.  Really bad
+%   thing.  We start off by stepping our absolute counter and making a
+%   mark.  \cmd{\leavevmode} is required so that the action of
+%   |perpage.sty| is done smoothly.
+%    \begin{macrocode}
+\def\FN@fnotecommon#1#2#3{%
+  \leavevmode
+  \stepcounter{FN@totalid}%
+  \NCC@makemark{#3}%
+%    \end{macrocode}
+%   It is an error if the footnote insert number of the current
+%   footnote does not correspond to a block below the current
+%   insertion level.
+%    \begin{macrocode}
+  \ifnum#2<\FN@masterinsert
+    \FN@colorstackbgroup\MFL@minipage
+    \FN@newslot\FN@masterslot
+    \count@\FN@id
+%    \end{macrocode}
+%   \cmd{\dimen@} is here set to a sorting criterion.  This is
+%   designed to make the conversion of footnote blocks as reliable as
+%   possible.  If we could guarantee convergence, just using
+%   \cmd{\c@FN@totalid} would be sufficient for sorting.  It turns out
+%   that this is too sensitive to footnotes of different blocks
+%   changing pages, so the number of the superior footnote block is
+%   allowed to take precedence by multiplying it with 4194304 which is
+%   unlikely to get exceeded by \cmd{\c@FN@totalid}.
+%    \begin{macrocode}
+    \dimen@=\dimexpr64\p@*\FN@masterinsert-\c@FN@totalid sp\relax
+    \def\FN@masterinsert{#2}%
+    \edef\FN@errorstack{\FN@errorstack^^J%
+\FN@masterinsert\space entered in line \number\inputlineno}%
+    \let\FN@boxtype=#1%
+    \setbox\z@#1\bgroup
+%    \end{macrocode}
+%   The following is for the likes of PDF\TeX\ which has its own idea
+%   about how to restore a color stack.
+%    \begin{macrocode}
+      \let\current@color\default@color
+      \FN@@color@begingroup
+      \let\MFL@minipage\relax
+      \let\MFL@endminipage\relax
+      \@makefnstartbox
+%    \end{macrocode}
+%   We reset the list parameters in footnotes.  Strictly speaking,
+%   this is interfering with \LaTeX's standard operation, but the
+%   standard operation does not make sense.
+%    \begin{macrocode}
+      \let\@listdepth\@mplistdepth \@mplistdepth\z@
+      \@itemdepth\z@ \@enumdepth\z@
+      \protected@edef\@currentlabel{\csname p@footnote%
+         \expandafter\FN@stripfootins\string#2\endcsname\@thefnmark}%
+      \ifx\FN@boxtype\vbox \normalcolor\nobreak
+      \else \FN@specific{#2}\@preparefnhtext \normalcolor
+      \fi
+%    \end{macrocode}
+%   After preparation, we now do the big bad trick for making
+%   footnotes cooperate with \cmd{\verb} and other catcode changing
+%   things: we call \cmd{\@makefntext} with an argument of
+%   |\iffalse|.  This kills off its expansion right at the point
+%   where it would choose to place its argument.
+%    \begin{macrocode}
+      \FN@specific{#2}\@makefntext
+      \iffalse\fi
+%    \end{macrocode}
+%   Record the footnote specific dimensions.  It is assumed that they
+%   don't change in the document, at least not before the footnote
+%   gets actually placed.
+%    \begin{macrocode}
+      \expandafter\xdef\csname FN@ht\number#2\endcsname{\the\footnotesep}%
+      \expandafter\xdef\csname FN@dp\number#2\endcsname{\the\dp\strutbox}%
+%    \end{macrocode}
+%   The footnote gets markers for identifying it and its starting block.
+%    \begin{macrocode}
+      \marks\FN@master{\FN@masterslot}%
+      \marks\FN@slave{\number\FN@id}%
+      \nobreak
+      \bgroup
+        \aftergroup\FN@commonending
+%    \end{macrocode}
+% \cmd{\FN@commonending} will intervene before any tokens that are
+% shifted in due to switching back the color stack.  Those will only
+% be executed once we completely relinquish control.
+%    \begin{macrocode}
+        \ifx\FN@boxtype\vbox
+           \rule\z@\footnotesep
+        \else
+          \ifx\FN@par\par\else
+            \let\FN@@par\par
+            \let\FN@@noindent\noindent
+            \let\FN@@indent\indent
+          \fi
+           \everyvbox\expandafter{\expandafter\everyvbox
+             \expandafter{\the\everyvbox}%
+             \let\par\FN@@par
+             \let\noindent\FN@@noindent
+             \let\indent\FN@@indent
+             \the\everyvbox}%
+           \let\par\FN@par
+           \let\noindent\FN@noindent
+           \let\indent\FN@indent
+        \fi
+        \afterassignment\ignorespaces
+        \expandafter\FN@fnotecommonii
+      \else
+%    \end{macrocode}
+%   We still needed to cater for the error of badly anchored footnotes:
+%    \begin{macrocode}
+    \PackageError{bigfoot}{#2 forbidden in \FN@masterinsert.}%
+    {Higher-placed footnotes can't be anchored in inferior ones.^^J%
+    I am not putting this text in a footnote.  History:%
+\FN@errorstack}%
+    \rule{1em}{\ht\strutbox}%
+\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@fnotecommonii}
+%   This just swallows the opening brace of the footnote text and then
+%   lets the footnote text progress.  The closing group will then
+%   trigger the processing via \cmd{\aftergroup}.
+%    \begin{macrocode}
+\def\FN@fnotecommonii#{\let\next}
+%    \end{macrocode}  
+% \end{macro}
+% % Ok, color handling is a nuisance, to say the least.  Split
+% footnotes need to close their color stack on the old page, and reopen
+% it on the new one.  So we record the color stack state at each time
+% it changes in a marks register.
+%    \begin{macrocode}
+\newmarks\FN@color
+\def\FN@colorstackbgroup{\let\FN@savecolorstack\FN@colorstack
+  \global\let\FN@colorstack\@empty
+  \bgroup
+  \ifdefined\FN@savecolorstack\else
+    \let\FN@@set@color\set@color
+    \let\FN@@reset@color\reset@color
+    \let\FN@@color@begingroup\color@begingroup
+  \fi
+  \let\set@color\FN@set@color
+  \let\reset@color\FN@reset@color
+  \let\color@begingroup\FN@color@begingroup}
+
+\def\FN@colorstackegroup{\egroup\ifx\FN@colorstack\@empty
+  \global\let\FN@colorstack\FN@savecolorstack \fi}
+
+\def\FN@colorstackfinish{\def\@elt##1##2{\FN@@reset@color##2}%
+  \FN@colorstack
+  \def\@elt##1##2{\noexpand\@elt{}{##2}}%
+  \xdef\FN@colorstack{\FN@colorstack}%
+  \let\@elt\relax
+  \marks\FN@color{}}
+
+\def\FN@reset@color{%
+  \bgroup\def\@elt##1##2{\def\FN@next{##1}{\gdef\FN@colorstack{##2}}}%
+    \let\FN@next\@empty
+    \FN@colorstack
+    \ifx\FN@next\@empty
+      \FN@colorstackegroup
+    \else \egroup
+      \FN@@reset@color
+      \marks\FN@color{\FN@colorstack}%
+  \fi}
+
+\def\FN@color@begingroup{%
+  \let\reset@color\FN@@reset@color
+  \let\color@begingroup\FN@@color@begingroup
+  \let\set@color\FN@@set@color
+  \color@begingroup}
+
+\def\FN@set@color{\FN@@set@color
+  \xdef\FN@colorstack{\@elt{\current@color}{\FN@colorstack}}%
+  \marks\FN@color{\FN@colorstack}}
+
+\def\FN@coloraftersplit#1{%
+  \def\@elt##1##2{##2\def\current@color{##1}\set@color}%
+  #1%
+  \let\@elt\relax}
+%    \end{macrocode}
+% \begin{macro}{\FN@commonending}
+%   We'll eventually arrive here at the end of the footnote.  Now we
+%   again call \cmd{\@makefntext}, but this time pass it |\fi| as
+%   its argument, and place |\iffalse| before its expansion.  This
+%   cuts away the start of the macro.  If this start changes the tail
+%   of the macro when executed, the whole trickery will not work.  It
+%   turns out that a large sampling of document classes (including the
+%   standard ones) happens to work.
+%    \begin{macrocode}
+\def\FN@commonending{%
+  \expandafter\expandafter\expandafter
+  \expandafter\expandafter\expandafter\expandafter
+  \iffalse  \FN@specific\FN@masterinsert\@makefntext\fi
+  \@makefnendbox
+  \ifx\FN@boxtype\vbox\@finalstrut\strutbox \else \unskip \fi
+  \FN@colorstackfinish
+  \color@endgroup
+  \egroup
+  \global\advance\FN@id\@ne
+  \FN@slotxdef\FN@masterslot{\number\FN@id}%
+%    \end{macrocode}
+%   Now we want to get an upper estimate of the size.  In case of a
+%   horizontal box, we do this by creating a vertical box of it all
+%   alone, and measuring that.  Measuring the hbox itself is plain
+%   out: \TeX's maximal dimension of something like 5\,m is already
+%   busted with about two pages of material.  We put the master slot
+%   identification into the depth of the box, and arrange for the
+%   total of depth and height of the box to still give the total depth
+%   and height of its size on the page.
+%    \begin{macrocode}
+  \ifhbox\z@
+    \global\setbox\FN@tempbox\copy\z@
+    \setbox\tw@\@makefnvbox{\unhbox\FN@tempbox}%
+    \ht\z@\dimexpr\ht\tw@+\dp\tw@-\FN@masterslot sp\relax
+  \else
+    \ht\z@\dimexpr\ht\z@+\dp\z@-\FN@masterslot sp\relax
+  \fi
+%    \end{macrocode}
+%   Now we put the sorting criterion into the width of the box, and
+%   then put the masterslot id into the depth.
+%    \begin{macrocode}
+  \wd\z@\dimen@
+  \dp\z@\FN@masterslot sp\relax
+%<trace>      \ifnum\z@<0\FN@slotget{\FN@masterslot} %
+%<trace>      \else \errmessage{Inconsistent
+%<trace>        \string\FN@masterslot=\FN@masterslot}\fi
+%    \end{macrocode}
+%   Now we just need to place the stuff into an insertion and record
+%   the possibly changed slave id in order to know what subordinate
+%   footnotes belong to this one.
+%    \begin{macrocode}
+  \MFL@insert\FN@masterinsert{\nointerlineskip\box\z@}%
+  \marks\FN@slave{\number\FN@id}%
+  \MFL@endminipage
+  \FN@colorstackegroup
+}
+%    \end{macrocode}
+% \end{macro}
+% A lot of stuff follows.  This should really be cleaned up and
+%   documented.
+%    \begin{macrocode}
+\dimen\footins\maxdimen
+\gdef\FN@nestlist{}
+
+\newdimen\FN@outervsize
+\newskip\FN@vsize
+
+\newbox\FN@insertions
+
+%<trace>\def\MFL@showone#1#2{\message{Box #2:}\showbox#2%
+%<trace>  \MFL@checkconsistency{#2}%
+%<trace>  \message{Cachebox #2:}\showbox\FN@cache#2}
+%<trace>
+%<trace>\def\MFL@checkconsistency#1{{%
+%<trace>  \setbox\z@\vbox{\unvcopy#1%
+%<trace>    \MFL@checkconsistencyi{#1}}}}
+%    \end{macrocode}
+% \begin{macro}{\MFL@checksinglebox}
+%   Check box~|#1| for consistency.  If it is bad, output box~|#2|.
+%   Execute |#3| if it was good, |#4| if it was bad.
+%    \begin{macrocode}
+%<trace>\def\MFL@checksinglebox#1#2#3#4{%
+%<trace>    \ifvoid#1\else
+%<trace>      \ifnum\z@<0\FN@slotget{\number\dp#1} %
+%<trace>        #3%
+%<trace>      \else \errmessage{Inconsistent box #2}%
+%<trace>         \showboxdepth4\showboxbreadth100
+%<trace>         \showbox#2\relax
+%<trace>         #4%
+%<trace>      \fi\fi}
+%    \end{macrocode}
+% \end{macro}
+%    \begin{macrocode}
+%<trace>\def\MFL@checkconsistencyi#1{%
+%<trace>    \unpenalty\unskip\unkern
+%<trace>    \setbox\z@\lastbox
+%<trace>    \MFL@checksinglebox\z@{#1}{{\MFL@checkconsistencyi{#1}}}{}}
+%<trace>
+%<trace>\def\MFL@showall{{%
+%<trace>    \showboxbreadth=\maxdimen
+%<trace>    \showboxdepth=4
+%<trace>    \tracingonline=\@ne
+%<trace>    \FN@nest@iterate\MFL@showone}}
+%    \end{macrocode}
+% \begin{macro}{\FN@retaindelayed}
+%   This is a complex macro that removes all boxes from the current
+%   list that are not to be kept for the next page.  It works on the
+%   material from the original insertions, not the cache boxes.
+%   The slot specified by \cmd{\count@} is not freed when encountered,
+%   all others are freed upon removing the box.  The last box is
+%   returned in box~0 if any is retained.  The vertical list might
+%   have an unchecked part locked off in front by placing a
+%   \cmd{\nobreak} penalty there.  This penalty is removed, and the
+%   list before it not touched.
+%    \begin{macrocode}
+\def\FN@retaindelayed{%
+  \setbox\z@\lastbox
+  \ifcase
+    \ifvoid\z@\m@ne\fi \FN@config\z@
+%<trace>  \if\foottrace8\message{^^J\string\FN@retaindelayed:
+%<trace>     dropping box \FN@slotget{\number\dp\z@}}\fi
+%<trace>  \if\foottrace{16}{\showboxdepth4 \showboxbreadth400
+%<trace>     \tracingonline=\@ne\showbox\z@}\fi
+    \ifnum\dp\z@=\count@\else \FN@freeslot{\number\dp\z@}\fi
+%<trace> \ifnum\dp\z@<\@ne \errmessage{Unidentified box}\fi
+    \FN@retaindelayed
+  \or
+%<trace> \if\foottrace8\message{^^J\string\FN@retaindelayed:
+%<trace>    retaining box \FN@slotget{\number\dp\z@}}\fi
+%<trace>  \if\foottrace{16}{\showboxdepth4 \showboxbreadth400
+%<trace>     \tracingonline=\@ne\showbox\z@}\fi
+    {\FN@retaindelayed \nointerlineskip \box\z@}%
+  \else \unpenalty \setbox\z@\lastbox
+%<trace>  \ifnum\lastnodetype>\m@ne
+%<trace>    \errmessage{Unexpected node \number\lastnodetype}\fi
+%<trace>  \ifvoid\z@ \else
+%<trace>     \if\foottrace8\message{^^J\string\FN@retaindelayed:
+%<trace>        carrying split box \FN@slotget{\number\dp\z@}}\fi
+%<trace>     \if\foottrace{16}{\showboxdepth4 \showboxbreadth400
+%<trace>        \tracingonline=\@ne\showbox\z@}\fi\fi
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\MFL@processplain}
+%   This gets called for actually inserting the processed material
+%   into the footnote box.  The current state of affairs is that
+%   \cmd{\FN@config} contains all footnotes that should get
+%   transferred to the next page completely.  The cache boxes contain
+%   the collected and typeset footnotes for typesetting on the current
+%   page.
+%
+%   The structure of a cachebox is currently as follows: it is filled
+%   with vboxes containing the arranged material, optionally followed
+%   by another box to be carried over to the next page flagged with a
+%   \cmd{\nobreak} penalty.
+%    \begin{macrocode}
+\def\MFL@processplain#1{%
+%<trace> \MFL@checkconsistency#1%
+   \ifvoid\FN@cache#1%
+%    \end{macrocode}
+% Now if the cache box is void, nothing gets typeset on the current
+% page.  What we do, however, is to collect all boxes from the
+% original insertion that did not make it on this page and reinsert
+% them.  \cmd{\count@} is cleared to zero to retain nothing special.
+%    \begin{macrocode}
+     \global\setbox\FN@tempbox\vbox\bgroup
+       \unvbox#1%
+       \count@\z@
+       \let\@elt\FN@removecheck \FN@retaindelayed
+       \ifvoid\z@ \egroup
+       \else \nointerlineskip \box\z@ \egroup
+         \MFL@realinsert{#1}{\unvbox\FN@tempbox}%
+       \fi
+%    \end{macrocode}
+% The following stops in the insertion process within the |manyfoot|
+% package.
+%    \begin{macrocode}
+     \expandafter\expandafter
+   \fi\iffalse\fi
+%    \end{macrocode}
+% Ok, this is the case when we have a nonvoid cache box.
+%    \begin{macrocode}
+   \global\setbox#1\vbox\bgroup%
+     \unvbox\FN@cache#1%
+     \ifnum\lastpenalty>\z@
+       \unpenalty
+       \setbox\z@\lastbox
+     \else
+       \setbox\z@\box\voidb@x
+     \fi
+%    \end{macrocode}
+% Ok, now box zero contains carryover material (if any).  We
+% initialize \cmd{\count@} to this so that we will keep this carryover
+% material just once.
+%    \begin{macrocode}
+     \count@\dp\z@
+     \global\setbox\FN@tempbox\vbox\bgroup
+       \box\z@
+       \nobreak
+       \unvbox#1%
+       \let\@elt\FN@removecheck \FN@retaindelayed
+       \ifvoid\z@ \egroup \MFL@removevboxes\egroup
+       \else \nointerlineskip \box\z@ \egroup
+         \MFL@removevboxes \egroup
+         \MFL@realinsert{#1}{\unvbox\FN@tempbox}%
+       \fi}
+
+\let\MFL@processpara\MFL@processplain
+%    \end{macrocode}
+% \end{macro}
+% Ok, here is the bit about the caches: whenever we encounter a new
+% configuration, we have to first update the caches since we don't
+% know the sizes we are dealing with regarding the new configuration
+% until we do so.  The caches are kept up to date globally.  When we
+% are working at several levels in the recursion, we have a bottom
+% active level where we may are looking for a way to find a best break
+% and configuration.  We will return at most one configuration once we
+% are finished.  While we are working with a returned configuration,
+% adding more material on the current list will not require another
+% recursion as long as the totals stay underfull: the penalty
+% difference between underfull configurations becomes smaller while
+% the underfullness decreases, which means that smaller breaks that
+% have not been chosen before might become eligible if the penalties
+% allow for that.  Only when the badness of underfullness remains
+% infinite can't we have any improvement.
+%
+% Ok, after we recurse for removing an underfull condition, the
+% resulting configuration can't actually be used further for breaks
+% with less remaining space.  It is, however, clear that if less space
+% remains, there is no better break with the same configuration
+% leaving \emph{more} space: if there were, it would already have been
+% taken.  That means that our goal height for the next break will be
+% chosen in order to reach the exact size met on the last recursion.
+% No break before that can be chosen on the next try, but a break
+% after it might then be taken.
+%
+% available, or an overfull one.  If a deeper level at any point of
+% time returns an overfull configuration, we are finished.  The best
+% configuration to be returned is the least underfull.  If there is
+% none, the least overfull.  The case of no underfull at all can only
+% happen if even splitting this and every subordinate level to minimal
+% height and recursing does not yield an underfull.  At every level,
+% we need to maintain just a current split, and the previous best
+% split at most.
+%
+% When we change a configuration on recursing, we have to remember the
+% configurations for the previous best split.  We can manage that by
+% sweeping the current cache values into a local box register
+% before recursing with a different configuration: we have to rebuild
+% the box registers for a different configuration, anyway.  We don't
+% save the configuration from an overfull setting: when we rework the
+% list in slow motion mode, we can't help stopping the recursion by
+% reaching an overfull setting that is at least as good as the
+% initial one.
+%
+% When we return to a caller, we leave the cache in the configuration
+% of the best choice up to now: either we are returning an overfull
+% configuration and if it is not the best so far, the caller can
+% restore his better choice from his copy, or we are returning an
+% underfull configuration in which case the caller might still want to
+% improve upon it before returning to its caller in turn.  New: If we
+% return an underfull configuration, we also return an ``optimal
+% penalty estimate'' that gives the best break point penalty under the
+% assumption that additional stretchability is present on the page.
+%
+% The purpose of this is to offer the possibility of avoiding widows
+% and similar by moving more material in some footnotes to the next
+% page in exchange for other material.
+%
+% At the current grouping level we empty out our current cache and
+% keep it for working purposes on the vertical list until we return
+% (nobody references it while we are working on it).  We always enter
+% with an overfull configuration, meaning that \cmd{\FN@vsize} is
+% negative.  It is calculated with the current cache\slash config
+% setting.
+%
+% There is a danger of overflow involved with that: if we keep a swept
+% complete configuration at each level of recursion, we need $O(n^2)$
+% of space here.  The alternative would be to keep the history of how
+% the configuration came about.  Since that might involve some
+% slow-motion splitting, this is also a speed issue.  Since deep
+% recursion with pending best data at each level is not really
+% likely, and since we are not going to have that many footnote
+% levels to go around, anyway, we just rely on \LaTeX\ having been
+% started with sufficient memory.
+%
+% A workable compromise would be to just store the split boxes
+% from a configuration together with the configuration data for
+% reconstructing the rest.  After all, we don't need to reconsider
+% such a configuration before actually typesetting anything.  And
+% whenever we find an acceptable fit (neither underfull\slash
+% overfull), we could cut through all the hierarchy without having to
+% restore anything.  This has not been implemented yet: at the moment
+% we go for the less complicated variation.
+%
+%
+% The algorithm we use here is a bit complicated.  Whenever we
+% recurse, we have one of the following situations:
+% \begin{enumerate}
+% \item An overfull/underfull dilemma: including a minimal amount of
+%       material at the current level will cause the page to become
+%       overfull.  This can be the case in connection with zero (in
+%       case of interline penalties for larger blocks), one or more
+%       subordinate footnotes and related footnotes.
+% \item A pure overfull dilemma: the page was overfull to start with,
+%       we need to reduce it.
+% \item an underfull dilemma: some operation in the next level made
+%       the page become underfull, only too much so.  We can't make it
+%       fuller on the current level, but we can make it even emptier,
+%       and let the next level fill it up again.
+% \end{enumerate}
+%
+% In the current implementation, we just ignore the slight probability
+% that the optimum choice might lie with case~3.  We don't
+% recurse for making the page fuller again.  If we have an
+% overfull/underfull dilemma, the recursion will either give us a
+% less awful overfull box, or an underfull one.  An overfull box that
+% occurs at the highest level of recursion can't be improved on any
+% lower level.  So we never need to locally return an overfull box: we
+% can compare it to the best overfull box seen before, and if we turn
+% out better than that, we overwrite the global best overfull value
+% and return the best local underfull if there is such a one.  The
+% best local underfull will then be refilled as much as possible on
+% the next level without changing the configuration.  Actually, if we
+% need to change the configuration, this would also be fine as long as
+% we arrive at a better underfull eventually.  But since a change of
+% configuration renders our previous split completely useless, as the
+% broken paragraph could look disastrously different under a changed
+% configuration, we would need to recurse again.  We repeat this
+% recursing operation until we don't get an underfull solution
+% returned anymore.  We then return the best underfull, if any.  The
+% best overfull is stored globally, as mention before.
+%
+% Does this sound complicated?  Unfortunately, it does.  It also
+% sounds somewhat slow.  For that reason, we do a few assumptions that
+% will facilitate a good average-case behavior.  The first assumption
+% is that we will usually do fine by just splitting in the current
+% level (if at all) and not at all in subordinate levels.
+%
+% We do this assumption on the first pass used for gathering the size
+% information and collect the corresponding boxes in nested lists.
+% When the recursion tops out, it does so either with an overfull
+% page, or an underfull page.  If it does with an underfull page, we
+% cache the current configuration for the next pass through the output
+% routine, so that we won't need to retypeset and measure assembled
+% boxes that have not gathered any new material.  If we top out with an
+% overfull page, the previous underfull configuration is still worth
+% keeping as well, as it might become the material actually chosen to
+% be typeset.
+%
+% Ok, the current best configuration of the next recursion level is
+% gathered on the current vertical list, in a separate box.  We use
+% box~2 for this purpose.  A saved configuration consists of the
+% complete contents for the current cache box without the trailing
+% penalty indicating material from a single split box carried over to
+% the next page (boxes that are carried over completely to the next
+% page are not maintained here but rather reinserted by
+% \cmd{\MFL@processnested}).  This penalty is added in case the box
+% is actually disassembled and returned: there is no possibility for
+% confusion since we only save such a configuration if indeed there is
+% a split present.
+%    \begin{macrocode}
+\newtoks\FN@output
+\FN@output\output
+
+\newbox\FN@tempbox
+\newinsert\FN@savebox
+\count\FN@savebox\@m
+\dimen\FN@savebox\maxdimen
+\skip\FN@savebox\z@skip
+\global\setbox\FN@savebox\box\voidb@x
+
+\expandafter\expandafter\expandafter\let\FN@cache\FN@savebox=\@cclv
+
+\expandafter\def\csname FN@ht\number\FN@savebox\endcsname{\topskip}%
+\expandafter\def\csname FN@dp\number\FN@savebox\endcsname{\maxdepth}
+
+\def\FN@list{\MFL@list\@elt{}\footins}
+
+\def\FN@sweepbox#1#2{\ifvoid#2\else
+  \nointerlineskip\box#2\penalty#2\fi}
+
+\def\FN@sweepcachebox#1#2{\nointerlineskip
+  \box\FN@cache#2%
+  \penalty\FN@cache#2}
+
+\def\FN@copycachebox#1#2{\nointerlineskip
+  \copy\FN@cache#2%
+  \penalty\FN@cache#2}
+
+\def\FN@restoreboxes{\count@\lastpenalty \unpenalty
+  \ifnum\count@>\z@
+    \global\setbox\count@\lastbox
+    \expandafter\FN@restoreboxes
+  \fi}
+%    \end{macrocode}
+% \begin{macro}{\FN@removecheck}
+%   This returns |\@ne| if and only if the current slot master is strictly
+%   inside of the specified interval.
+%    \begin{macrocode}
+\def\FN@removecheck#1#2{%
+  \ifnum#1<\FN@slotget{\number\dp\z@} %
+  \ifnum#2>\FN@slotget{\number\dp\z@} %
+    \@ne\fi\fi}
+%    \end{macrocode}
+% \end{macro}
+% Parameter recording merely records the relevant value of the
+% skip register and sets it to zero.  The purpose is to avoid changes
+% of the reserved page space when we collect additional material from
+% a page where an insertion of the appropriate kind had already been
+% encountered.  This is used for filling up underfull pages.
+%    \begin{macrocode}
+\def\FN@recordinsertparam#1#2{\ifvoid#2\else
+  \global\skip\number#2=\the\skip#2\relax\fi}
+
+\def\FN@clearinsertparam#1#2{\ifvoid#2\else
+  \global\skip#2=\z@skip\fi}
+%    \end{macrocode}
+% \cmd{\FN@insertouterspace} will sum the size of the inserts manually.
+%    \begin{macrocode}
+\def\FN@insertouterspace#1#2{\ifvoid#2\else
+    +\skip#2+(\ht#2+\dp#2)*\count#2/\@m\fi}
+
+\def\FN@list@iterate#1{\let\FN@eltsave\@elt
+  \let\@elt#1%
+  \FN@list
+  \let\@elt\FN@eltsave}
+
+\def\FN@nest@iterate#1{\let\FN@eltsave\@elt
+  \let\@elt#1%
+  \FN@nestlist
+  \let\@elt\FN@eltsave}
+%    \end{macrocode}
+%
+% \subsection{The output routine stuff}
+%
+% \paragraph{Marks}
+% This is used for sweeping all marks up for reinsertion.
+% \begin{macro}{\FN@allmarks}
+%    \begin{macrocode}
+\def\FN@allmarks#1{\@elt{#1}%
+  \ifnum#1<\count266
+    \expandafter\FN@allmarks\expandafter{\number\numexpr#1+\@ne}%
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@sweeptopmarks}
+% \begin{macro}{\FN@topmarkbox}
+%   This sweeps the current topmarks and places them into the global box
+%   \cmd{\FN@topmarkbox}.
+%    \begin{macrocode}
+\def\FN@sweeptopmarks{\global\setbox\FN@topmarkbox\vbox{%
+    \def\@elt##1{\marks##1{\unexpanded\expandafter{\topmarks##1}}}%
+    \FN@allmarks0}}
+\newbox\FN@topmarkbox
+%    \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \begin{macro}{\FN@establishmarks}
+%   This sets marks from a marks sweep.  The first argument is the
+%   mark number, the second is from the first mark on the first scan,
+%   the third argument from the bottom mark on the first scan, and the
+%   fourth argument from the bottom mark on the second scan (with
+%   additional mark entries).  If second and third arguments don't
+%   match, no mark gets placed.
+%    \begin{macrocode}
+\long\def\FN@establishmarks#1#2{\edef\reserved@a{\unexpanded{#2}}%
+  \edef\reserved@b{\unexpanded\expandafter{\splitbotmarks#1}}%
+  \ifx\reserved@a\reserved@b
+    \marks#1{\unexpanded\expandafter{\splitfirstmarks#1}}%
+    \marks#1{\unexpanded\expandafter{\reserved@b}}%
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@markspassone}
+%   This constitutes the first pass for mark collection.  We do this
+%   just to check whether there are any marks in the list.
+%    \begin{macrocode}
+\def\FN@markspassone#1{\noexpand\FN@establishmarks{#1}%
+  {\unexpanded\expandafter{\splitbotmarks#1}}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@insertmarks}
+%   This routine transfers first and bottom marks from the current
+%   |\box255| to the vertical list in order to get the marks right.
+%   This is quite a bother, since we must detect the special case
+%   where there are no marks at all in the list, and since we might
+%   require the use of several \cmd{\vsplit} commands in a row, since
+%   infinite stretch might make the optimal breakpoint lie before the
+%   end of the box in spite of its large size.
+%
+%   So we need to do the splitting in a loop, and do it twice, once
+%   with artificial marks at the start.  If those artificial marks
+%   make it to \cmd{\splitbotmarks}, we don't place any actual marks.
+%    \begin{macrocode}
+\def\FN@pseudomarks#1{\marks#1{X}}
+\def\FN@insertmarks{%
+  {\setbox\z@\copy\@cclv
+    \splittopskip-\maxdimen\relax
+    \vbadness=\maxdimen
+    \loop
+    \ifvoid\z@\else
+      {\let\@elt\FN@pseudomarks
+        \setbox\z@\vbox{\FN@allmarks0\nobreak\unvcopy\z@}%
+        \setbox\z@\vsplit\z@ to\maxdimen}%
+      \let\@elt\FN@markspassone
+      \edef\next{\FN@allmarks0}%
+      \setbox\z@\vbox{\nobreak\unvbox\z@}%
+      {\setbox\z@\vsplit\z@ to\maxdimen}%
+      \next
+    \repeat}}
+%    \end{macrocode}
+% \end{macro}
+% \paragraph{Some stuff}
+%
+% \begin{macro}{\FootnoteMainMinimum}
+%   This specifies the minimum amount of main text.  You can make this
+%   a complicated expression if you want to, for example by checking
+%   the presence of particular footnotes.
+%    \begin{macrocode}
+\def\FootnoteMainMinimum{0pt}
+%    \end{macrocode}
+% \end{macro}
+%
+%\paragraph{The output routine itself}
+%
+% This is our own output routine that does all the balancing stuff.
+% If we receive a forced penalty here, we must not do any of our
+% output processing on our own unless this is the choice of the
+% underlying output routine.  We do want to have the `real' output
+% routine to have a correct idea about the size that the insertions
+% will take up.  So the steps that we \emph{will} actually perform in
+% any case are sorting the insertions and calculating their real
+% size.  If we have not had a forced penalty, we are free to exit the
+% output routine for gathering further material as there are no
+% expections of the underlying output routine when it should get
+% called.  If we encountered a forced penalty, things are getting more
+% complicated.  If the current page happens to be overfull after
+% adding the current material, we first need to ship out the material
+% for a regular page (after splitting off the necessary material for
+% the next page).  We then reinsert the remaining split insertions,
+% any possibly split off page material and the penalty.
+%
+% \TeX is rather monotonous in its page break processing.  Increase
+% the available page size, and the available page material will also
+% increase.  There is a singular exception to that rule, and that are
+% split and floating insertions.  However, we notice their presence by
+% a non-zero setting of \cmd{\insertpenalties}, and we can just
+% measure the material that they have taken up in a forced pass of the
+% output routine, adding that much to our request size.  However, this
+% operation will change the penalties associated with the page breaks.
+%
+% Unfortunately, this is not sufficient: the penalty might have been
+% inserted with a box immediately preceding it.  In that case the
+% penalty would have been guaranteed to eventually turn up in the
+% output routine.  If we now reinsert merely all of the above stuff,
+% the penalty will just disappear.  If we protect the penalty by
+% placing an empty box before it when none of it had been before it
+% before, we will get an empty page.  Since we don't know whether the
+% penalty was supposed to disappear at the start of an empty page or
+% not, we will do the following: if the rest of |\box255| is nonvoid,
+% we just reinsert the split insertions followed by the rest of
+% \box255 and the penalty and return.  If it is void, we call the
+% regular output routine, capturing its output in a |\vbox| of its
+% own.  If the regular output routine failed to ship out the prepared
+% insertions, we just keep the original data either in their boxes or
+% in a reinserted insertion.
+%
+% It hides the relevant information from the `real' output routine
+% until such a time that we have enough material gathered to produce a
+% full page.  The exception to this is when we have a special penalty
+% that gets passed through to the regular output routine.
+%
+% If we are on a material collecting spree, \cmd{\FN@savebox} contains
+% all boxes from the last output call time.  At the point where we
+% enter the output routine, \cmd{\FN@vsize} contains the amount of
+% space available for mounting footnotes, after subtracting all
+% insertions of footnote variety.  At most times in our output
+% routine, the variable will contain the amount of space left after
+% everything is put to the page including footnotes.
+%    \begin{macrocode}
+\savingvdiscards=\@ne
+%    \end{macrocode}
+% We have the following situations that can cause us to enter the
+% output routine:
+% \begin{enumerate}
+% \item The page has just filled up.
+% \item A magic output penalty has been encountered.
+% \item We are filling up a previously underfull page.
+% \item We are looking for missing insertions that may have floated.
+% \end{enumerate}
+%
+% In the situation where the page break has already been determined
+% (magic output penalty, looking for missing insertions), we are not
+% interested in `foreign' insertions like floating figures.  The
+% current code does not cater for them.
+%
+% If the output routine is invoked with a penalty of $-13750$, then
+% the page content is merely used for setting the \cmd{\topmarks}
+% array.  In that case, we just clear out the output box and resume.
+% We don't fiddle with \cmd{\deadcycles} in order to catch foulups.
+% Also we don't touch insertion boxes.  There is a particular
+% situation where there \emph{are} insertions, namely if we are
+% collecting insertions after the last output routine has ended up
+% with a non-zero value of \cmd{\insertpenalties}.  In this case, all
+% insertions we \emph{do} get are floating insertions, meaning that
+% the had a preceding insertion of the same class already on the last
+% page, and thus we have zeroed its skip register already.  We are
+% assuming that a single pass with such a large \cmd{\vsize} is
+% sufficient for pulling all insertions.  If that happens to be
+% incorrect, insertions need to get pulled in piecewise, but then we
+% are probably in big dodo with regard to page size accounting,
+% anyway.
+%    \begin{macrocode}
+\output{%
+%<trace> \if\foottrace8%
+%<trace>   \message{entering output with
+%<trace>      \outputpenalty=\the\outputpenalty:}%
+%<trace>   \showbox\@cclv\fi
+% \ifnum\c@page=10 \traceon\fi
+  \ifnum\outputpenalty=-13750
+%<trace>  \if\foottrace8%
+%<trace>    \message{Discarding box 255.}%
+%<trace>  \fi
+    \ifnum\insertpenalties>\z@
+      \PackageError{bigfoot}{Too much insertion material}{%
+        This error means that the output routine was not able to^^J%
+        gather all floating insertions in a single pass.^^J%
+        Complain to the author if you consider this a bug}%
+    \fi
+    \global\advance\FN@outervsize\dimexpr\ht\@cclv-\vsize\relax
+    \global\setbox\@cclv\box\voidb@x
+  \else
+%    \end{macrocode}
+% Note that a potential \cmd{\FN@vsadjustlist} will restore the
+% previous value of \cmd{\outputpenalty}.  So we need to save it.
+%    \begin{macrocode}
+  \edef\FN@outputpenalty{\number\outputpenalty}%
+  \ifvoid\FN@savebox
+    \ifvoid\@holdpg
+      \FN@sweeptopmarks
+    \fi
+    \ifvoid\@cclv
+      \global\FN@outervsize\z@
+    \else
+      \global\FN@outervsize\ht\@cclv
+      \global\setbox\@cclv\vbox{\unvbox\@cclv\boxmaxdepth\maxdepth}%
+      \global\advance\FN@outervsize-\ht\@cclv\relax
+    \fi
+    \global\let\FN@vsadjustlist\@empty
+    \FN@normaloutput
+%    \end{macrocode}
+% \cmd{\FN@outervsize} now contains the amount of stretch that was put
+% into the output box in order to reach the goal size.  So it is the
+% space we still have left available to fill given the current
+% \cmd{\vsize} and contents of insertions.  Note that this can be
+% negative if shrinkability has been involved in getting at the value.
+%    \begin{macrocode}
+  \else
+%    \end{macrocode}
+% We now are in the situation that we already have collected material
+% previously.  \cmd{\FN@outervsize} contains the overshoot according
+% to the difference of demanded and achieved space again.  It remains
+% unchanged if we have inserted a special penalty ourselves: in this
+% case no page material has possibly been added.  However, we can't be
+% sure that adding a special penalty does not take more than one
+% output routine call before delivery.  For that reason, we don't rely
+% on special outputs being special and always subtract any
+% additionally demanded \cmd{\vspace} from \cmd{\FN@outervsize} before
+% calling a special output, so that we can afterwards compensate for
+% it.
+%    \begin{macrocode}
+    \ifvbox\@cclv
+      \dimen@\ht\@cclv
+      \global\setbox\@cclv\vbox{\unvbox\@cclv\boxmaxdepth\maxdepth}%
+      \global\advance\FN@outervsize\dimexpr\dimen@-\ht\@cclv\relax
+    \fi
+%    \end{macrocode}
+% Now we invalidate the cache boxes for all insertions that had
+% changed due to the recent additions to the page.
+%    \begin{macrocode}
+    \FN@nest@iterate\FN@maybeinvalidatecache
+%    \end{macrocode}
+% We now update all boxes by inserting the previously collected
+% material in front of the boxes.
+%    \begin{macrocode}
+    \vskip\z@skip
+    \unvbox\FN@savebox
+    \loop
+      \count@\lastpenalty
+    \ifnum\count@>\z@
+      \unpenalty
+      \setbox\z@\lastbox
+      \global\setbox\count@\vbox{\unvbox\z@\unvbox\count@}%
+    \repeat
+    \ifcase
+      \ifnum\FN@outputpenalty=-13749 \@ne\fi
+      \ifnum\FN@outputpenalty=-13751 \@ne\fi \tw@
+    \or
+      \FN@vsadjustlist
+%<trace> \if\foottrace8\message{receiving special penalty
+%<trace>    \FN@outputpenalty, dissing box 255:}%
+%<trace>      {\showboxdepth4 \showboxbreadth400
+%<trace>       \tracingonline=\@ne\showbox\@cclv}\fi
+%    \end{macrocode}
+% We don't need to insert either discards or outputpenalties anywhere:
+% those are exclusively derived from our own inserted code.
+% Since the \cmd{\pagediscards} derive from our own insertion, we
+% clear them out.  \cmd{\outputpenalty} is restored to the original
+% value before the total page is glued together.
+%    \begin{macrocode}
+      \global\setbox\@cclv\vbox{\pagediscards}%
+%    \end{macrocode}
+% This special penalty means that we have been collecting floated
+% insertions right now.  So |\box255| is actually empty except for
+% filler material.  We restore the old box into it.
+%    \begin{macrocode}
+      \global\setbox\@cclv\lastbox
+      \unskip
+%<trace>  \ifnum\lastnodetype>\m@ne
+%<trace>    \errmessage{Unexpected node \number\lastnodetype}\fi
+      \ifnum\FN@outputpenalty=-13749
+        \FN@normaloutput
+      \else
+        \the\FN@output
+      \fi
+    \else
+      \dimen@\topskip
+      \FN@vsadjustlist
+      \setbox\z@\lastbox
+      \unskip
+%<trace>  \ifnum\lastnodetype>\m@ne
+%<trace>    \errmessage{Unexpected node \number\lastnodetype}\fi
+%    \end{macrocode}
+% Ok, now we reconstruct the box from its parts.  We add the material
+% together, taking the previous output penalty and the current page
+% discards for glueing the stuff together.  The previous output
+% penalty then is irrelevant for further purposes and we replace it
+% again.  \cmd{\FN@outervsize} has been
+% adjusted by the accumulated contributions of insertions to the page
+% size.  Fiddling with it would not appear necessary or even prudent.
+%    \begin{macrocode}
+      \global\setbox\@cclv\vbox{\unvbox\z@
+        \ifnum\outputpenalty<\@M \penalty\outputpenalty\fi
+        \pagediscards
+%    \end{macrocode}
+% Now we might have had a \cmd{\topskip} value designed for requesting
+% a given number of lines.  We need to remove anything of that kind.
+% Splitting again achieves that.
+%    \begin{macrocode}
+        \ifvbox\@cclv
+          \global\setbox\@cclv\vbox{\break\unvbox\@cclv}%
+          {\splittopskip-\maxdimen \setbox\z@\vsplit\@cclv to\z@}%
+          \unvbox\@cclv
+        \fi
+        \boxmaxdepth\maxdepth}%
+      \global\outputpenalty\FN@outputpenalty\relax
+%    \end{macrocode}
+% Ok, now if \cmd{\topskip} is actually \emph{positive}, we have been
+% collecting material tentatively without having proper marks.  We
+% then need to fill in the marks into the list and try again.
+%    \begin{macrocode}
+      \ifdim\dimen@>\z@
+%<trace>  \if\foottrace8
+%<trace>    \message{recycling special penalty}
+%<trace>  \fi
+        \hrule\@height\z@\@depth\z@
+        \unvcopy\FN@topmarkbox
+        \penalty-13750
+        \hrule\@height\z@\@depth\z@
+        \FN@insertmarks
+        \penalty-13749
+        \FN@prepareoutput
+        \global\topskip-\maxdimen
+        \global\vsize0.5\maxdimen
+        \global\advance\FN@outervsize-\vsize
+      \else
+        \FN@normaloutput
+      \fi
+   \fi
+  \fi
+  \fi}
+%    \end{macrocode}
+% \begin{macro}{\FN@normaloutput}
+%   This is the normal output routine we use.
+%   Now we have recovered a sensible state and glued everything together
+%   that has been necessary.  All insertion parameters are at their
+%   standard values, and any insertions have been collected in the
+%   respective boxes.  If the whole exercise has been 
+%    \begin{macrocode}
+\def\FN@normaloutput{%
+%    \end{macrocode}
+% \cmd{\FN@vsize} is now being set to the vertical size taken up by
+% the insertions, according to \TeX.  Note that this does not include
+% flexibility.  This much amount of space gets available on the
+% current page if we remove all insertions.  This figures into
+% \cmd{\FN@vsize} as a \emph{positive} quantity since the insertion
+% size was taken from \cmd{\pagegoal}, and we reconstitute it in this
+% manner.
+%    \begin{macrocode}
+  \FN@nest@iterate{\FN@insertouterspace\global\FN@vsize\dimexpr\z@}%
+%    \end{macrocode}
+% Now we sort the inserts and regenerate the cache.
+%    \begin{macrocode}
+  \FN@nest@iterate\FN@sortinsert
+  \FN@nest@iterate\FN@clearcache
+  \xdef\FN@config{\noexpand\@elt{\number0\botmarks\FN@slave}%
+    {\number\maxdimen}}%
+  \FN@nest@iterate\FN@reconfig
+%    \end{macrocode}
+% Note that \cmd{\FN@reconfig} subtracts the \emph{actual} size of all
+% insertions (after paragraphs have been combined and too early
+% insertions moved to the next page) and also subtracts the flexible
+% glues associated with the insertions' skip registers, so this
+% flexibility is typically negative.
+%    \begin{macrocode}
+  \global\advance\FN@vsize\FN@outervsize\relax
+  \ifcase
+    \ifnum\insertpenalties>\z@ \@ne\fi
+%    \end{macrocode}
+% If we have floating insertions, we need to catch up with them.  This
+% is done in case~1 which just places an immediate penalty and
+% recurses.
+%
+% Now here are a few cases that are only checked when we don't have a
+% special penalty:
+%    \begin{macrocode}
+    \ifnum\outputpenalty>-\@M
+%    \end{macrocode}
+% The first case is if the page is underfull.  We need more material then.
+%    \begin{macrocode}
+      \ifdim\FN@vsize>-\gluestretch\FN@vsize \tw@ \fi
+%    \end{macrocode}
+% Second case is when there is not enough vertical minimum material.
+%    \begin{macrocode}
+      \ifdim\FootnoteMainMinimum>\ht\@cclv \tw@ \fi
+    \fi
+%    \end{macrocode}
+% Case 3 means page is overfull.  If there are no missing insertions,
+% try to split.
+%    \begin{macrocode}
+    \ifdim\FN@vsize<\glueshrink\FN@vsize \thr@@ \fi
+%    \end{macrocode}
+% 
+% page has appropriate size or we have special penalty.  If we have
+% come here not the first time, we might have arrived at a non-optimal
+% break.  So we attempt a split.
+%    \begin{macrocode}
+    \ifx\FN@vsadjustlist\@empty \else \thr@@\fi\z@
+    \ifvbox\@cclv
+      {\vbadness\maxdimen
+        \global\setbox\@cclv\vbox
+          spread\FN@vsize{\unvbox\@cclv\boxmaxdepth\maxdepth}}%
+    \fi
+    \the\FN@output
+    \FN@nest@iterate\FN@clearcache
+  \or
+%    \end{macrocode}
+% Case 1: We just pull in remaining insertions and are done.
+%    \begin{macrocode}
+    \FN@restartoutput
+    \penalty -13749
+%    \end{macrocode}
+% Now we want to gather additional material.  This is somewhat weird.
+% We first gather our material with a `normal' setting of topskip, and
+% then we'll have another go at the material using proper marks.  We
+% can't actually insert anything right now in order not to introduce a
+% premature breakpoint.
+%    \begin{macrocode}
+  \or
+    \dimen@=\dimexpr\FN@vsize-\glueshrink\FN@vsize\relax
+    \FN@prepareoutput
+    \global\topskip \normalbaselineskip
+    \global\vsize \dimen@ 
+    \global\advance\FN@outervsize-\vsize
+    \global\deadcycles\z@
+  \else
+%    \end{macrocode}
+% Fake our output box into something looking like a cache box
+%    \begin{macrocode}
+    \edef\FN@masterid{\number\maxdimen}%
+    \def\FN@masterslot{-1}%
+    \global\setbox\@cclv\vbox{%
+      \box\@cclv}%
+    \xdef\FN@config{\noexpand\@elt{\number0\botmarks\FN@slave}%
+      {\number\maxdimen}}%
+%<trace> \ifvoid\FN@savebox \else \PackageError{bigfoot}{\FN@savebox
+%<trace>   \space should be void!}{}\fi
+    \global\setbox\FN@savebox\vbox{}%
+    \gdef\FN@badness{0}%
+    \edef\FN@defaultpenalty{\ifnum\outputpenalty<\@M
+        \number\outputpenalty
+      \else
+        0\fi}%
+    \let\@elt\FN@newlevel
+    \@elt{}\FN@savebox\FN@nestlist\FN@mainsplitreturn
+    \let\@elt\relax
+%<trace> \if\foottrace8{\showboxdepth4\showboxbreadth100\showbox\@cclv}\fi
+    \global\setbox\FN@savebox\box\voidb@x
+    \count@\vbadness
+    \vbadness\maxdimen
+    \global\setbox\@cclv\vbox spread\FN@vsize\bgroup
+      \unvbox\@cclv
+      \ifnum\lastpenalty>\z@
+        \unpenalty
+        \global\setbox\FN@tempbox\lastbox
+      \else
+        \global\setbox\FN@tempbox\box\voidb@x
+      \fi
+      \setbox\z@\lastbox
+      \ifvoid\z@
+        \ifvbox\FN@tempbox
+          \ifnum\outputpenalty<\@M
+            \global\setbox\FN@tempbox{\unvbox\FN@tempbox
+              \penalty\outputpenalty}%
+          \fi
+          \global\outputpenalty=\@M
+        \fi
+        \egroup \global\setbox\@cclv\box\voidb@x
+      \else
+        \MFL@removevboxes
+        \unvbox\z@
+        \let\FN@defaultpenalty\@M
+        \FN@getbreakpenalty
+        \setbox\z@\lastbox
+        \ifcase
+          \ifvbox\FN@tempbox \@ne\fi
+          \ifvoid\z@ \else \@ne\fi \z@
+        \or
+          \global\setbox\FN@tempbox\vbox{\unvbox\z@
+            \unvbox\FN@tempbox
+            \ifnum\outputpenalty<\@M
+              \penalty\outputpenalty
+            \fi}%
+          \global\outputpenalty\FN@breakpenalty
+        \fi
+        \boxmaxdepth\maxdepth\egroup
+      \fi
+    \vbadness\count@
+    \setbox\z@\box\FN@tempbox
+    \let\@elt\relax
+%    \end{macrocode}
+% Ok, now we have in box~255 the split off stuff for the current
+% output routine, and in box~0 stuff that is going to follow
+% afterwards.  If box~0 is not void, we were not able to make use of
+% all of box~255.  There is a slight probability that by taking even
+% \emph{more} material from the main list, we might get a better
+% result (by being able to move footnote material to the next page
+% instead), but we don't make use of this possibility here.  In
+% general, we assume that if box~0 is nonvoid, we take the resulting
+% split.  Otherwise, if the page appears underfull, we pull in more
+% material.  If the page is not underfull, we can pass it to the
+% output routine.
+%    \begin{macrocode}
+    \dimen@=\dimexpr\FN@vsize-\glueshrink\FN@vsize\relax
+    \ifcase
+      \ifvoid\z@ \else\thr@@\fi
+      \ifdim\ht\@cclv<\normalbaselineskip \@ne\fi
+      \ifdim\dimen@<\normalbaselineskip \tw@\fi \@ne
+    \or
+      \FN@prepareoutput
+      \global\topskip \normalbaselineskip
+      \ifdim\dimen@<\normalbaselineskip \dimen@=2\baselineskip\fi
+      \global\vsize \dimen@ 
+      \global\advance\FN@outervsize-\vsize
+      \global\deadcycles\z@
+    \or
+%<trace> \if\foottrace8%
+%<trace>   \message{^^JOutput: config is \FN@config...}\fi
+    \setbox\tw@\vbox{%
+      \the\FN@output
+%<trace> \if\foottrace8%
+%<trace>   \ifnum\lastnodetype=\m@ne
+%<trace>     \message{^^JOutput: end without carryover^^J}%
+%<trace>   \else
+%<trace>     \message{^^JOutput: end with carryover}}%
+%<trace>      {\showboxdepth5 \showboxbreadth400
+%<trace>      \tracingonline=\@ne\showbox\tw@
+%<trace>   \fi
+%<trace> \fi
+    }%
+    \unvbox\tw@
+    \unvbox\z@
+    \FN@nest@iterate\FN@clearcache
+  \or
+      \FN@restartoutput
+      \penalty -13751
+      \unvbox\z@
+  \fi
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@prepareoutput}
+%   This is a preparation for gathering more material.  First sweep up
+%   all the information about \cmd{\vsize}, \cmd{\topskip} and
+%   \cmd{\outputpenalty}.  After that, record the insertion skip
+%   parameter of all insertions that have already been started, and
+%   reset them to zero so that no additional space gets reserved for
+%   them in case more material accumulates.  We don't reset
+%   \cmd{\topskip} here since the amount of newly requested material
+%   will typically be in total lines, and \cmd{\topskip} might be the
+%   only way to figure out the proper request size.  If the current
+%   depth and following height would make for a non-standard line
+%   distance, we might have a problem here.  There is no obvious way
+%   to avoid it, though.
+%    \begin{macrocode}
+\def\FN@prepareoutput{%  
+  {\let\@elt\FN@recordinsertparam
+   \xdef\FN@vsadjustlist{%
+     \global\vsize=\the\vsize
+     \global\topskip=\the\topskip
+     \global\outputpenalty=\the\outputpenalty\relax
+     \FN@list}%
+   \let\@elt\FN@clearinsertparam
+   \FN@list}%
+%    \end{macrocode}
+%   Now we collect all boxes in the save box.
+%    \begin{macrocode}
+%<trace> \ifvoid\FN@savebox \else \PackageError{bigfoot}{\FN@savebox
+%<trace>   \space should be void in \string\FN@prepareoutput}{}\fi
+  \global\setbox\FN@savebox\vbox{%
+    \box\@cclv
+    \FN@list@iterate\FN@sweepbox}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@restartoutput}
+%   This is for the case where we are requesting additional material
+%   and have to cater for sizes.
+%    \begin{macrocode}
+\def\FN@restartoutput{%
+%    \end{macrocode}
+% Calculate the remaining size on this page:
+%    \begin{macrocode}
+  \dimen@=\dimexpr\FN@vsize-\glueshrink\FN@vsize\relax
+%    \end{macrocode}
+% We just pull in remaining insertions and are done.
+%    \begin{macrocode}
+%<trace> \if\foottrace8\message{sending special penalty}\fi
+  \hrule\@height\z@\@depth\z@
+  \unvcopy\FN@topmarkbox
+  \penalty -13750
+  \hrule\@height\z@\@depth\z@
+  \FN@insertmarks
+  \FN@prepareoutput
+  \global\topskip-\maxdimen\relax
+  \global\vsize 0.5\maxdimen
+  \global\advance\FN@outervsize-\vsize
+  \global\deadcycles\z@
+}
+%    \end{macrocode}
+% \end{macro}
+%
+% Ok, here is the deal.  If the \cmd\FN@truevsize is negative, we have
+% an overfull vbox at our hand.  We then start the splitting action.
+% We take the first non-split lowest footnote block and split it to
+% size, removing subordinate footnotes that we would not be able to
+% maintain.  We do this recursively starting by the top footnote
+% block.  It must be noted that it would be even better to start with
+% the highest-numbered footnote (which corresponds to the latest
+% finished footnote in \emph{logical} order, that in the source code),
+% but then we get the problem that we might have to remove boxes from
+% a footnote block that has already been split, and that is
+% troublesome (to put it mildly) in case where the footnote block is
+% set in paragraph mode.  It's bad enough backtracking in a fixed
+% order across footnote blocks, going back and forward would be pretty
+% tough.
+%
+% So our recursion just walks the footnote blocks once top to bottom,
+% splitting and removing boxes that are not needed.  When we recurse,
+% we have a dichotomy between current overfull and underfull boxes.
+% At each recursion level, we enter with an overfull configuration
+% that establishes the breakable section for the footnote block in
+% question.
+%
+% Suppose that we have already established a previous best
+% configuration.  When we are recursing, we can only increase the
+% badness (a non-broken insertion box contributes nothing to the
+% overall badness or penalties, breaking the box causes a badness of
+% 10000, minus the break penalty, plus the break badness).  So there
+% is no point in recursing if entry badness and break penalty are as
+% large as the previous best break penalty or more.
+%
+% Ok, so we construct the footnote block and try splitting it
+% to size.  If this
+% gives us a \emph{good} underfull version, we return that (and break
+% out of recursion altogether).  Otherwise we remember the underfull
+% version before the break and recurse on the overfull version.  If
+% this returns an overfull version again, we return the underfull
+% version before the break.  If it returns an underfull version, we
+% fill up the underfull version as much as possible without a change
+% of configuration, then select the best of the last underfull and
+% this as new local underfull.  We then take the first overfull
+% combination (even allowing a change of configuration), throw away
+% the previous split in the next recursion level and recurse on the
+% now thoroughly overfull combination again.
+%
+% When recursion tops out, we compare the current overfull with the
+% previous one and record the best.  We prefer keeping an older
+% overfull, all other things being equal.
+%
+% Ok, so what are the data structures we maintain when going through
+% all this folderol?
+%
+% We let the insertion boxes themselves remain untouched: that makes
+% it only a bit more complicated to maintain and access the relevant
+% boxes, but it might come handy at one time when somebody wants to
+% implement recursion that is not strictly top-to-bottom.
+%
+% Instead we return the relevant information in the cache boxes.  The
+% total size of the cache boxes may not correspond to their actual
+% contents: in case a split box intended for the next page is stored
+% within them, its height is deducted from the total height of the
+% cache box (and, consequentially, from \cmd{\FN@vsize}).
+%
+% \cmd{\FN@vsize}, the amount of free space on the current page, is
+% only updated when changing levels of recursion.  Instead we maintain
+% score of the accumulated size in the current insertion in
+% \cmd{\FN@myvsize}.
+%
+% What about the penalties and badness we collect?  An unsplit
+% footnote block carries a penalty of~0 (so we need not take into
+% account unsplit footnote blocks at all during our bookkeeping, as
+% they are neutral), a split footnote block is prepenalized with a
+% penalty of~10000, plus the badness of the split, plus any penalties
+% associated with the split (limited to the $[-10000\ldots10000]$
+% range).  This means that no operation on other footnote blocks can
+% lower an already accumulated score.  This in turn means that we can
+% prune any operations leading to a worse score than the preceding
+% best score without having to actually recurse.
+%
+% This strategy will usually buy us a minimum number of split
+% footnotes (since the penalty of~10000 is not easy to compensate)
+% and corresponds rather closely to \TeX's own idea of footnote
+% splitting.
+%
+% The following routine will analyze the last box where the results
+% from \cmd{\splitdiscards} are stored and return the penalty
+% associated with the breakpoint in the macro
+% \cmd{\FN@breakpenalty}.
+% \begin{macro}{\FN@getbreakpenalty}
+%    \begin{macrocode}
+\def\FN@getbreakpenalty{{\setbox\z@\lastbox
+    \nointerlineskip\copy\z@
+    \setbox\z@
+      \vbox{\unvbox\z@
+        \count@\FN@defaultpenalty\relax
+        \FN@getbreakpenaltyii
+        \xdef\FN@tempinfo{\edef\noexpand\FN@breakpenalty{%
+            \number\ifnum\count@>-\@M \count@
+                   \else -\@M \fi}}}}%
+  \FN@tempinfo}
+
+\def\FN@getbreakpenaltyii{%
+  \ifcase
+    \ifnum\lastnodetype<\z@ \m@ne\fi
+    \ifnum\lastnodetype<11 \@ne\fi
+    \ifnum\lastnodetype>13 \@ne\fi
+    \numexpr\lastnodetype-9\relax
+  \or
+    \PackageError{bigfoot}{Illegal node type}{This can't happen}%
+  \or
+    \count@\z@ \unskip \expandafter\FN@getbreakpenaltyii
+  \or
+    \count@\z@ \unkern \expandafter\FN@getbreakpenaltyii
+  \or
+    \count@\lastpenalty
+    \unpenalty \expandafter\FN@getbreakpenaltyii
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@mainsplitreturn}
+%   This is merely an argument delimiting control sequence to make it
+%   possible to figure out which recursion levels still need visiting.
+%    \begin{macrocode}
+\def\FN@mainsplitreturn{}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@myvsize}
+%   This is the size currently taken by this insertion.
+%    \begin{macrocode}
+\newdimen\FN@myvsize
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bigfoottolerance}
+%   This specifies what footnote arrangement penalty will be accepted
+%   without looking for a better solution.
+%    \begin{macrocode}
+\newcount\bigfoottolerance
+\bigfoottolerance=100
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@getbadness}
+%   This takes a skip value of remaining space and negative
+%   stretchability and shrinkability, and then calculates
+%   \cmd{\badness} depending on how good the stretching accommodates
+%   the remaining space.
+%    \begin{macrocode}
+\def\FN@getbadness#1{%
+  {\hfuzz\maxdimen\hbadness\maxdimen\setbox\z@\hbox to\z@{\hskip-#1}}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@newlevel}
+%   This is the main workhorse of |bigfoot|.  It splits a particular
+%   footnote level, recursing if necessary.  The level list is
+%   delimited with \cmd{\FN@mainsplitreturn}.  The whole thing is
+%   looped through while the splits are being optimized.  While
+%   recursing, \cmd{\FN@badness} contains the badness of the current
+%   split configuration: a penalty of $10000$ for any split, plus the
+%   penalty at the split points.  \cmd{\FN@ebadness} is the same, but
+%   also counting in the stretch badness for one particular
+%   configuration.  Ebadness does not make sense to evaluate more than
+%   temporarily: it is not passed through the levels.  Since
+%   \cmd{\FN@badness} is globally tampered with, its value at entry is
+%   saved in \cmd{\FN@entrybadness}.
+%    \begin{macrocode}
+\def\FN@newlevel#1#2#3\FN@mainsplitreturn{%
+  \count@\FN@cache#2%
+  \ifvoid\count@
+%<trace> \if\foottrace1\message{Page=\thepage #2 is empty, recursing with
+%<trace>   \the\FN@vsize^^J}%
+%<trace>   \message{Config=\FN@config^^J}\fi
+      #3\FN@mainsplitreturn
+%<trace> \if\foottrace1%
+%<trace>   \message{Page=\thepage #2 was empty, returning with \the\FN@vsize^^J}%
+%<trace>   \message{Config=\FN@config^^J}\fi
+  \else
+%<trace> \if\foottrace1\message{Entering #2 with \FN@badness}\fi
+    {\def\FN@currentinsertion{#2}%
+     \def\FN@currentrecursion{#3}%
+     \let\FN@entryconfig\FN@config
+     \let\FN@entrybadness\FN@badness
+     \splittopskip\csname FN@ht\number#2\endcsname\relax
+     \splitmaxdepth\csname FN@dp\number#2\endcsname\relax
+     \vbadness=\maxdimen
+     \vfuzz\maxdimen
+     \let\@elt\relax
+     \expandafter\FN@newleveli\expandafter}%
+%<trace> \if\foottrace1\message{Exiting #2 with \FN@badness}\fi
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@newleveli}
+%    \begin{macrocode}
+\def\FN@newleveli{%
+%    \end{macrocode}
+% \cmd{\FN@vsize} already includes the size of the complete unsplit
+% insertion.  When we recurse, it has to reflect the correct size at
+% the time of recursion.  Rounding error problems don't permit us to
+% accumulate any sizes in \cmd{\FN@vsize} from processing our current
+% insertion, so we just subtract the whole insertion-related
+% content.  We'll add stuff into it when recursing.
+%    \begin{macrocode}
+    \dimen@\dimexpr\ht\count@+\dp\count@\relax
+    \global\advance\FN@vsize\dimexpr \dimen@
+      *\count\FN@currentinsertion/\@m\relax\relax
+%    \end{macrocode}
+% Ok, now we are typesetting and collecting the best box.  Notice
+% that we \emph{don't} exit this \cmd{\setbox} command until we have
+% found the best possible split.  What we \cmd{\unvbox} here, stays
+% dormant except for the last box.  When we collect configurations
+% from cache boxes, we don't collect anything from our current box
+% that is being assembled.  So the whole action is confined within the
+% current list that will replace the cache box after splitting.  The
+% meaning of boxes on the various levels are:\par\noindent
+% \begin{tabularx}{\linewidth}{ll@{:\hskip\tabcolsep}X}
+%   0&box0&where stuff gets collected as tentative material to be
+%   unboxed with |\FN@removevboxes| once the insertion gets readied
+%   for shipout\\
+%   0&box2&the previous best split that was found\\\hline
+%   1&box0&the material that gets worked off, the tail of the split\\
+%   1&box2&where the current split is assigned
+% \end{tabularx}
+% The structure of 0/box2 is the head of the split, followed by
+% |\break| penalty, followed by the tail of the split, followed by
+% |\penalty\FN@tempbox|, followed by pairs of cache boxes and
+% penalties indicating their box number.  That way, the tail can get
+% restored immediately into |\FN@tempbox| when using
+% |\FN@restoreboxes|.
+%    \begin{macrocode}
+    \global\setbox\count@\vbox\bgroup\unvbox\count@
+%    \end{macrocode}
+% We calculate \cmd{\FN@myvsize} as the total space taken up by this
+% insertion.  The size of the last box is excluded since it will be
+% split now.
+%    \begin{macrocode}
+      \ifnum\lastpenalty=\z@
+        \setbox\tw@\box\voidb@x
+        \setbox\z@\lastbox
+        \FN@myvsize=\dimexpr\dimen@-\ht\z@-\dp\z@\relax
+      \else
+%    \end{macrocode}
+% Now if the box has been split previously, we glue it back together
+% again.
+%    \begin{macrocode}
+        \unpenalty
+        \setbox\tw@\lastbox
+        \setbox\z@\lastbox
+        \FN@myvsize=\dimexpr\dimen@-\ht\z@-\dp\z@\relax
+        \dimen@\dp\z@
+        \setbox\z@{\unvbox\z@
+          \setbox\z@\lastbox
+          \unvbox\z@
+          \unvbox\tw@}%
+        \ht\z@=\dimexpr\ht\z@+\dp\z@-\dimen@\relax
+        \dp\z@\dimen@
+      \fi
+%    \end{macrocode}
+% Ok, size is all accounted for.  Go on with optimization.  Note that
+% these definitions here are made in \emph{inner} level, so they can't
+% make it outside as the result of the optimization.  If we drop out
+% of here without superceding them, something's completely rotten.
+%    \begin{macrocode}
+      \edef\FN@bestebadness{\number\maxdimen}%
+      \let\FN@bestconfig\@undefined
+      \let\FN@bestvsize\z@skip
+      \let\FN@splitcolors\@empty
+%    \end{macrocode}
+% Ok, first attempt.  One interesting feature is that we will never
+% have to rewind the boxes from a split: we can always just glue the
+% box together again.  And apart from tentative splits which we might
+% revert if they cause a configuration change, we will not have to
+% bother about contributing too much.  What we put in the box here
+% can stay.
+%
+% First we split to the remaining size.  After having done so, we
+% continue splitting until we get the necessary mark of the last
+% footnote into our grasp: we can't split before that.
+%    \begin{macrocode}
+      \ifnum\FN@currentinsertion=\FN@savebox
+      \else
+        \def\FN@defaultpenalty{-\@M}%
+        \edef\FN@masterslot{\number\dp\z@}%
+        \edef\FN@masterid{\FN@slotget\FN@masterslot}%
+      \fi
+%    \end{macrocode}
+% Now we are building one tentative candidate for returning in
+% |\box\z@|.  It will get discarded in case that a better candidate
+% was already found before this box completes.
+%    \begin{macrocode}
+      \setbox\z@
+      \vbox\bgroup
+%    \end{macrocode}
+% Ok, now stuff gets complicated: for the first, tentatively `optimal'
+% split, we want to have all available page stretchability properly
+% taken into account.  So we take the box, and add the available page
+% stretchability at the top.  Note that the stretchability is
+% registered negatively.
+%    \begin{macrocode}
+        \let\FN@splitcolors\@empty
+        \setbox\z@\vbox{\vskip-\glueexpr(\FN@vsize-\dimexpr\FN@vsize
+          \relax\@minus\glueshrink\FN@vsize)%
+          *\@m/\count\FN@currentinsertion
+          \unvbox\z@
+          \ifnum\FN@defaultpenalty>-\@M
+            \penalty\FN@defaultpenalty\nointerlineskip
+            \vbox to\maxdimen{}%
+          \fi}%
+%    \end{macrocode}
+% Ok, now we have pushed the additional available stretch onto the top
+% of box~0.  Now we do the actual split to minimal size.  That means
+% that we don't consider any of the shrinkability available on the
+% page: it might still be better employed in some recursive level.
+%    \begin{macrocode}
+        \setbox\tw@\vsplit\z@ to%
+          \dimexpr\FN@vsize*\@m/\count\FN@currentinsertion
+          -\FN@myvsize
+        \relax
+        \ifnum\FN@defaultpenalty>-\@M
+          \setbox\z@\vbox\bgroup\unvbox\z@\setbox\z@\lastbox
+            \unpenalty
+            \ifnum\lastnodetype<\z@
+              \egroup \setbox\z@\box\voidb@x
+            \else
+              \egroup
+            \fi
+        \fi
+%    \end{macrocode}
+% Ok, now the top of box~2 contains unwanted additional
+% stretchability.  The easiest way to get rid of it is by adding its
+% negation.
+%    \begin{macrocode}
+        \setbox\tw@\vbox{%
+          \vskip\glueexpr(\FN@vsize-\dimexpr\FN@vsize
+          \relax\@minus\glueshrink\FN@vsize)%
+          *\@m/\count\FN@currentinsertion
+          \unvbox\tw@\boxmaxdepth\splitmaxdepth}%
+%    \end{macrocode}
+% Ok, now rinse and repeat if we don't have reached the last footnote
+% in the block.  Or, if we are in the main block and have not reached
+% the necessary minimum size.
+%    \begin{macrocode}
+        \ifnum\FN@currentinsertion=\FN@savebox
+          \edef\FN@slaveid{\splitbotmarks\FN@slave}%
+          \FN@contribute@tw@
+          \ifdim\FootnoteMainMinimum>\FN@myvsize
+            \loop
+              \setbox\tw@\vsplit\z@ to\z@
+              \edef\FN@slaveid{\splitbotmarks\FN@slave}%
+              \FN@contribute@tw@
+            \ifcase\ifdim\FootnoteMainMinimum>\FN@myvsize
+              \ifvoid\z@
+                \@ne
+              \else
+                \tw@
+              \fi\fi \z@
+            \or
+              \PackageWarning{bigfoot}{too little main material}%
+            \else
+            \repeat
+          \fi
+        \else
+          \ifnum0\splitbotmarks\FN@master=\FN@masterslot \else
+            \loop
+              \FN@contribute@tw@
+              \setbox\tw@\vsplit\z@ to\z@
+            \ifnum0\splitbotmarks\FN@master=\FN@masterslot
+            \else
+            \repeat
+          \fi
+          \let\FN@splitcolors\@empty
+          \edef\FN@slaveid{\splitbotmarks\FN@slave}%
+          \FN@contribute@tw@
+        \fi
+%    \end{macrocode}
+% All of the above was necessary to ensure that we actually have the
+% beginning of the relevant footnote in our material.  From now on,
+% we are dealing with legal splits.
+% Ok, now we have to check whether the subordinate configuration has
+% changed.
+%    \begin{macrocode}
+        \ifx\FN@slaveid\@empty
+%<trace>  \ifnum\FN@currentinsertion=\FN@savebox\else
+%<trace>    \errmessage{Missing slaveid in \FN@currentinsertion}\fi
+          \edef\FN@slaveid{\number0\topmarks\FN@slave}%
+        \fi
+        \ifnum\numexpr\FN@slaveid+\@ne<\FN@masterid
+          \let\FN@next\FN@slaveid
+        \else
+          \let\FN@next\@empty
+        \fi
+%    \end{macrocode}
+% At this point of time, we have \cmd{\FN@masterid} set properly for
+% our purposes.  It is to be used for returning any \emph{tail} part
+% of a box.  \cmd{\FN@slaveid} is by necessity not empty.  If any
+% footnote
+% has had its mark broken off, its id must be in the open range
+% between \cmd{\FN@slaveid} and \cmd{\FN@masterid}.  So a nonempty
+% value of \cmd{\FN@next} at this point of time indicates that we have
+% to cater for a different configuration rather than the currently
+% cached one.
+%    \begin{macrocode}
+        \FN@splitfurther}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@vsizerecurse}
+% This fixes the vertical size up and recurses once.
+%    \begin{macrocode}
+\def\FN@vsizerecurse{%
+    \global\advance\FN@vsize
+      -\dimexpr\FN@myvsize*\count\FN@currentinsertion/\@m \relax\relax
+    \let\@elt\FN@newlevel
+    \FN@currentrecursion\FN@mainsplitreturn
+    \let\@elt\relax
+    \global\advance\FN@vsize
+      \dimexpr\FN@myvsize*\count\FN@currentinsertion/\@m \relax\relax}
+%    \end{macrocode}
+% \end{macro}
+% 
+% \subsubsection{Main label for reconsideration}
+% When we are here, then there is not yet a split in the next footnote
+% blocks scheduled.  We might have to restitch stuff together here,
+% though.
+% \begin{macro}{\FN@splitfurther}
+%    \begin{macrocode}
+\def\FN@splitfurther{%
+  \ifx\FN@next\@empty \else \let \FN@slaveid\FN@next \fi
+%    \end{macrocode}
+% Ok, if our configuration now differs from the last one for which we
+% have cache boxes set up, we have to reconfigure.  It it doesn't, we
+% just stitch the boxes together again in order to have correct size
+% info.
+%    \begin{macrocode}
+  \let\FN@next\FN@config
+  \xdef\FN@config{%
+    \@elt{\FN@slaveid}%
+    {\FN@masterid}%
+    \FN@entryconfig}%
+  \ifx\FN@next\FN@config
+    \let\@elt\FN@rejoin
+  \else
+    \let\@elt\FN@reconfig
+  \fi
+  \FN@currentrecursion
+  \let\@elt\relax
+%    \end{macrocode}
+% Ok, now we check whether the current configuration is a match for
+% the best previous one.  Also we calculate the badness of the current
+% situation.
+%    \begin{macrocode}
+  \xdef\FN@badness{\number\FN@entrybadness}%
+  \FN@checkcurrent
+%    \end{macrocode}
+% No point in recursing if we can't beat the current best one.
+% However, if we find a forced break, this is considered perfect as
+% long as we are not overfull.  Note that recursion can only increase
+% the badness if we are still underfull here.
+%    \begin{macrocode}
+  \ifnum
+    \ifdim\skip@>\z@ \FN@ebadness \else \FN@badness \fi >\FN@bestebadness
+  \else
+    \xdef\FN@badness{\number\FN@entrybadness}%
+    \FN@vsizerecurse
+    \FN@checkcurrent
+  \fi
+%    \end{macrocode}
+% Don't look further if we had a forced break or are overfull or are
+% at the end of the list.
+%    \begin{macrocode}
+  \ifcase
+    \ifnum\FN@breakpenalty>-\@M \else \@ne \fi
+    \ifvoid\z@ \@ne \fi
+    \ifnum\badness<\@MM \else \@ne \fi
+    \tw@
+  \or
+    \expandafter \FN@returnbest
+  \else
+    \FN@mayberecordbest
+    \setbox\tw@\vsplit\z@ to\z@
+    \edef\FN@next{\splitbotmarks\FN@slave}%
+    \FN@contribute@tw@
+    \expandafter \FN@splitfurther
+  \fi}
+% \end{macro}
+% \begin{macro}{\FN@checkcurrent}
+%   Check out the badness of the current configuration.
+%    \begin{macrocode}
+\def\FN@checkcurrent{%
+  \skip@\glueexpr\FN@vsize-\FN@myvsize
+   *\count\FN@currentinsertion/\@m\relax
+  \FN@getbreakpenalty
+  \FN@getbadness\skip@
+  \xdef\FN@badness{\number\numexpr\FN@badness+%
+    \FN@breakpenalty+\@M}%
+  \ifnum\badness>\@M
+    \edef\FN@ebadness{\number\numexpr\maxdimen-\@ne}%
+  \else
+    \ifnum\badness=\@M
+      \edef\FN@ebadness{\number\numexpr\maxdimen-\tw@}%
+    \else
+      \edef\FN@ebadness{\number\numexpr
+        \FN@badness+\badness}%
+    \fi
+  \fi
+  \dimen@\glueexpr\FN@bestvsize\relax
+}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@checkforbest}
+%   This generates 2 if the old stored best is better, 1~if the
+%   current variation is better.
+%    \begin{macrocode}
+\def\FN@checkforbest{%
+    \ifnum\FN@breakpenalty>-\@M \else
+      \ifnum\badness>\@M \else
+         \@ne
+      \fi
+    \fi
+%    \end{macrocode}
+% Ok, so the split was not as good as to cause us to return
+% immediately, and it also was not the last opportunity for a split
+% (which again would make us return immediately).
+% So we check if it is at least better than the last one, in which
+% case we need to replace the previous best.
+%    \begin{macrocode}
+    \ifnum\FN@bestebadness>\FN@ebadness \@ne\fi
+    \ifnum\FN@bestebadness<\FN@ebadness \tw@\fi
+    \ifdim\skip@<\z@
+      \ifdim\dimen@<\skip@ \@ne \else \tw@\fi
+    \fi
+    \ifdim\dimen@>\skip@ \@ne\fi \tw@}
+%    \end{macrocode}   
+% \end{macro}
+% \begin{macro}{\FN@mayberecordbest}
+%   This checks whether the current configuration is better than a
+%   previously saved one.  If it is, the previous configuration gets
+%   replaced.  The cache boxes itself are copied, not voided in the
+%   process for efficiency reasons.
+%    \begin{macrocode}
+\def\FN@mayberecordbest{%
+%    \end{macrocode}
+% If the current break is forced and the page is not overfull, we take
+% the break.
+%    \begin{macrocode}
+  \ifcase
+    \FN@checkforbest
+  \or
+    \xdef\FN@tempinfo{\def\noexpand\FN@bestvsize{\the\skip@}%
+      \def\noexpand\FN@bestebadness{\FN@ebadness}%
+      \def\noexpand\FN@bestbadness{\number\FN@badness}%
+      \def\noexpand\FN@bestconfig{\FN@config}%
+      \def\noexpand\FN@bestslaveid{\FN@slaveid}%
+      \def\noexpand\FN@bestsplitcolors{\FN@splitcolors}%
+      \def\noexpand\FN@breakpenalty{\FN@breakpenalty}%
+      \FN@myvsize=\the\FN@myvsize\relax}%
+    \global\setbox\FN@tempbox\box\z@
+    \egroup
+    \FN@tempinfo
+    \let\FN@splitcolors\FN@bestsplitcolors
+    \let\FN@slaveid\FN@bestslaveid
+%    \end{macrocode}
+% Now all relevant info has been retrieved, and we collect the best
+% box info in |\box\tw@|.  The structure of the information is as
+% follows: it starts with the current box in split form, first the
+% tail, then the start of the current split box.
+% This is then followed by a zero kern, and then by pairs of boxes and
+% penalties indicating the swept box.
+%    \begin{macrocode}
+    \setbox\tw@\vbox{%
+%    \end{macrocode}
+% We don't need to place master/slave marks here: the necessary
+% information is available outside in the \cmd{\FN@masterslot} and
+% \cmd{\FN@slaveid} info and gets attached afterwards.
+%    \begin{macrocode}
+      \copy\z@\break\nointerlineskip
+      \copy\FN@tempbox\penalty\FN@tempbox
+      \let\@elt\FN@copycachebox
+      \FN@currentrecursion
+      \xdef\FN@tempinfo{\FN@myvsize=\the\FN@myvsize\relax}}%
+    \FN@tempinfo
+    \setbox\z@
+    \vbox\bgroup
+      \unvbox\z@
+      \setbox\z@\box\FN@tempbox
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+
+% \begin{macro}{\FN@returnbest}
+%    \begin{macrocode}
+\def\FN@returnbest{%
+  \ifcase\FN@checkforbest
+  \or
+    \xdef\FN@tempinfo{\def\noexpand\FN@bestvsize{\the\skip@}%
+      \def\noexpand\FN@bestebadness{\FN@ebadness}%
+      \def\noexpand\FN@bestbadness{\number\FN@badness}%
+      \def\noexpand\FN@bestconfig{\FN@config}%
+      \def\noexpand\FN@bestslaveid{\FN@slaveid}%
+      \def\noexpand\FN@bestsplitcolors{\FN@splitcolors}%
+      \def\noexpand\FN@breakpenalty{\FN@breakpenalty}%
+      \FN@myvsize=\the\FN@myvsize\relax}%
+    \global\setbox\FN@tempbox\box\z@
+    \egroup
+    \FN@tempinfo
+    \let\FN@splitcolors\FN@bestsplitcolors
+    \let\FN@slaveid\FN@bestslaveid
+    \global\FN@vsize\FN@bestvsize\relax
+%    \end{macrocode}
+% Now all relevant info has been retrieved, and we collect the best
+% box info in |\box\tw@|.  The structure of the information is as
+% follows: it starts with the current box in split form, first the
+% tail, then the start of the current split box.
+% This is then followed by a zero kern, and then by pairs of boxes and
+% penalties indicating the swept box.
+%    \begin{macrocode}
+  \or
+    \global\let\FN@config\FN@bestconfig
+    \global\FN@vsize\FN@bestvsize
+    \global\let\FN@badness\FN@bestbadness
+    \egroup
+%    \end{macrocode}
+% Restore the saved configuration.
+%    \begin{macrocode}
+    \setbox\z@\vbox{\unvbox\tw@ \FN@restoreboxes}%
+    \let\FN@splitcolors\FN@bestsplitcolors
+    \let\FN@slaveid\FN@bestslaveid
+    \unvbox\z@
+    \setbox\z@\lastbox
+  \fi
+%    \end{macrocode}
+%    \begin{macrocode}
+  \ifnum\FN@currentinsertion=\FN@savebox
+  \else
+    \setbox\z@\vbox{%
+      \dimen@\dp\z@
+      \unvbox\z@
+      \ifvoid\FN@tempbox
+      \else
+        \global\setbox\FN@tempbox\vbox{%
+          \marks\FN@master{\FN@masterslot}%
+          \marks\FN@slave{\FN@slaveid}%
+          \FN@coloraftersplit\FN@splitcolors
+          \nobreak
+          \unvbox\FN@tempbox}%
+        \ht\FN@tempbox
+        \dimexpr\ht\FN@tempbox+\dp\FN@tempbox-\FN@masterslot sp\relax
+        \dp\FN@tempbox\FN@masterslot sp\relax
+        \wd\FN@tempbox\maxdimen
+      \fi
+      \ifdim\dimen@<\splitmaxdepth
+        \hrule\@height-\dimen@ \@width\z@
+         \@depth \splitmaxdepth \relax \fi}%
+    \ht\z@=\dimexpr\ht\z@+\dp\z@-\FN@masterslot sp\relax
+    \dp\z@=\FN@masterslot sp
+  \fi
+  \nointerlineskip \box\z@
+%    \end{macrocode}
+% If nothing is to be carried over, we just finish our assignment to
+% the cache box and return.
+%    \begin{macrocode}
+  \ifvoid\FN@tempbox \egroup
+%    \end{macrocode}
+% If not, we add the carried-over box to the list, flag it with a
+% \cmd{\nobreak}, and subtract its size from the finished box.
+%    \begin{macrocode}
+  \else
+    \dimen@-\dimexpr\ht\FN@tempbox+\dp\FN@tempbox\relax
+    \nointerlineskip\box\FN@tempbox
+    \nobreak
+    \expandafter\egroup
+    \expandafter\ht\expandafter\count@\expandafter\dimexpr
+    \the\dimen@+\ht\count@\relax
+  \fi
+}
+%    \end{macrocode}
+% \end{macro}
+% 
+% \begin{macro}{\FN@contribute@tw@}
+%   This will go from the state where we have the previous
+%   \cmd{\splitdiscards} struttified on the current list some material
+%   split off from box~0 in box~2 to a state where box~2 is
+%   contributed to the current list.
+%    \begin{macrocode}
+\def\FN@contribute@tw@{%
+%    \end{macrocode}
+% First we change the current colors if we have any in our group.  Not
+% sure if this is entirely correct.
+%    \begin{macrocode}
+  \begingroup\edef\FN@next{\splitbotmarks\FN@color}%
+  \ifx\FN@next\@empty \endgroup\else \endgroup
+    \edef\FN@splitcolors{\splitbotmarks\FN@color}\fi
+%    \end{macrocode}
+% If the last box is void, there is no previous split to reconstitute.
+%    \begin{macrocode}
+  \setbox4\lastbox
+  \ifvoid4 \setbox4\vbox{\splitdiscards}%
+    \setbox\tw@\vbox{\unvbox\tw@\boxmaxdepth\splitmaxdepth}%
+  \else
+%    \end{macrocode}
+% Now the last box is a strut.  We remove its outer dimensions from
+% the total account, and then add back its natural dimensions after
+% which we pour it back into the current list.
+%    \begin{macrocode}
+    \advance\FN@myvsize-\dimexpr\ht4+\dp4\relax
+    \setbox4\vbox{\unvbox4}%
+    \advance\FN@myvsize\dimexpr\ht4+\dp4\relax
+    \unvbox4
+%    \end{macrocode}
+% We want to contribute box~2 back without any topskip glue, so we
+% manually remove any such glue by splitting an empty box off.
+%    \begin{macrocode}
+    \setbox4\vbox{\splitdiscards}%
+    \setbox\tw@\vbox{\break\unvbox\tw@}%
+    {\splittopskip-\maxdimen \setbox\tw@\vsplit\tw@ to\z@}%
+%    \end{macrocode}
+% Notice the effect of \TeX's special box scope rules: box~2 assigned
+% just right now will be affected by the split.  The result of the
+% split will be an empty box that will temporarily overwrite box~2
+% within the group, but will be restored back to the split result on
+% exit.  In this manner, any topskip glue will have disappeared.
+% After the split, box~2 is set to the natural depth and height of
+% its contents.
+%
+% We now add a sort of strut by putting all the discarded material
+% inside of a box that creates the proper size.
+% If this split is taken, the box is adjusted to have a full depth of
+% \cmd{\splitmaxdepth}, and we take this into account.
+%    \begin{macrocode}
+  \fi
+  \ht4-\dp\tw@
+  \dp4\ifdim\dp\tw@<\splitmaxdepth \splitmaxdepth \else \dp\tw@ \fi
+  \advance\FN@myvsize\dimexpr \ht\tw@+\dp4\relax
+  \unvbox\tw@
+  \nointerlineskip
+  \box4 }
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@uncontribute@tw@}
+%   This is just the opposite: after a split, we revert its effects again.
+%    \begin{macrocode}
+\def\FN@uncontribute@tw@{%
+  \ifvoid\tw@ \else
+  \setbox\tw@\vbox{\unvbox\tw@\splitdiscards}%
+  \setbox\z@\vbox{\break\unvbox\z@}%
+  {\splittopskip-\maxdimen \setbox\z@\vsplit\z@ to\z@}%
+  \setbox\z@\vbox{\unvbox\tw@\unvbox\z@}\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@reconfig}
+%   This reconfigures the insertion cache to contain only the boxes
+%   that belong to this page.  If the insertion box is empty, we can
+%   skip all the folderol.  If it isn't, we empty the cache box (the
+%   number of which we place in \cmd{\count@}) and add its size back
+%   to \cmd{\FN@vsize}.
+%    \begin{macrocode}
+\def\FN@reconfig#1#2{\ifvoid#2%
+%<trace> \ifvoid\FN@cache#2\else
+%<trace>    \errmessage{\FN@cache#2 should be void}\fi
+  \else
+  \count@\FN@cache#2%
+  \ifvoid\count@\else
+    \global\advance\FN@vsize
+      \glueexpr(\ht\count@+\dp\count@)*\count#2/\@m+\skip#2\relax
+    \global\setbox\count@ \box\voidb@x
+  \fi
+%    \end{macrocode}
+%   Ok, now we have emptied the cache and readjusted the size.  We now
+%   fill the cache by first copying the insertion into it.
+%    \begin{macrocode}
+  \global\setbox\count@\vbox\bgroup\vbox\bgroup\unvcopy#2%
+    \let\@elt\FN@removecheck
+    \FN@retainkept
+%    \end{macrocode}
+% Now if nothing was retained, we void the cachebox.
+%    \begin{macrocode}
+    \ifvoid\z@ \egroup\egroup \global\setbox\count@ \box\voidb@x
+%    \end{macrocode}
+% Otherwise, we combine all the boxes that remain on the page.
+%    \begin{macrocode}
+    \else \def\FN@masterinsert{#2}%
+      \FN@assembleboxes\global\setbox\count@\box\z@\egroup
+      \nointerlineskip\box\count@\egroup
+%    \end{macrocode}
+% Note that now all footnote boxes are collected into a single vbox,
+% followed by the last footnote box as another vbox.
+% Now we just need to reduce the available size on the page by the
+% height of the assembled material:
+%    \begin{macrocode}
+    \global\advance\FN@vsize
+      -\glueexpr(\ht\count@+\dp\count@)*\count#2/\@m+\skip#2\relax
+  \fi\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\FN@rejoin}
+%   This glues together cache boxes that have been split, without
+%   regenerating them.  This saves a lot of time as compared to
+%   \cmd{\FN@reconfig}.
+%    \begin{macrocode}
+\def\FN@rejoin#1#2{{%
+  \count@\FN@cache#2%
+  \ifvoid\count@\else
+    \global\advance\FN@vsize\dimexpr
+       (\ht\count@+\dp\count@)*\count#2/\@m\relax
+    \global\setbox\count@\vbox{%
+      \unvbox\count@
+      \ifnum\lastpenalty>\z@
+        \unpenalty
+        \setbox\tw@\lastbox
+        \setbox\z@\lastbox
+        \dimen@\dp\z@
+        \setbox\z@\vbox{%
+          \unvbox\z@
+          \setbox\z@\lastbox
+          \unvbox\z@
+          \unvbox\tw@}%
+        \ht\z@=\dimexpr\ht\z@+\dp\z@-\dimen@\relax
+        \dp\z@=\dimen@
+        \nointerlineskip
+        \box\z@
+      \fi}%
+    \global\advance\FN@vsize-\dimexpr
+        (\ht\count@+\dp\count@)*\count#2/\@m\relax
+  \fi}}
+%    \end{macrocode}
+% \end{macro}
+% 
+% \begin{macro}{\FN@retainkept}
+%  This relies on \cmd{\@elt} being set to \cmd{\FN@removecheck} which
+%  expands to \cmd{\@ne} if |\box0| is strictly between the two values
+%  from an entry of \cmd{\FN@config}, which means that it is material
+%  that should get moved to the next page.  In that case, we recurse
+%  while dropping the box in question.  Otherwise we keep it.
+%  Recursion bottoms out when there are no boxes left.  The function
+%  leaves the last retained box in box~0; if there are no boxes to be
+%  retained, this will be void.
+%    \begin{macrocode}
+\def\FN@retainkept{%
+  \setbox\z@\lastbox
+  \ifcase
+    \ifvoid\z@\m@ne\fi \FN@config\z@
+%<trace>  \if\foottrace8\message{^^J\string\FN@retainkept:
+%<trace>     retaining box \FN@slotget{\number\dp\z@}}\fi
+%<trace>  \if\foottrace{16}{\showboxdepth4 \showboxbreadth400
+%<trace>     \tracingonline=\@ne\showbox\z@}\fi
+    {\FN@retainkept \nointerlineskip \box\z@}%
+  \or
+%<trace>  \if\foottrace8\message{^^J\string\FN@retainkept:
+%<trace>     dropping box \FN@slotget{\number\dp\z@}}\fi
+%<trace>  \if\foottrace{16}{\showboxdepth4 \showboxbreadth400
+%<trace>     \tracingonline=\@ne\showbox\z@}\fi
+    \FN@retainkept
+%<trace>  \else
+%<trace>  \ifnum\lastnodetype>\m@ne
+%<trace>    \errmessage{Unexpected node \number\lastnodetype}\fi
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% Well, as the last measure, we change the output routine to our new
+% routine.
+%    \begin{macrocode}
+\let\output\FN@output
+%    \end{macrocode}
+% Ok, here is debugging code intercepting all calls of the regular
+% output routine and reporting its entry and exit states.
+%    \begin{macrocode}
+%<trace> \newtoks\FN@tr@output
+%<trace> \FN@tr@output\output
+%<trace> \output{\if\foottrace8{%
+%<trace>   \setbox\z@\vbox{%
+%<trace>     \message{Calling regular output with
+%<trace>       \outputpenalty=\the\outputpenalty, box255 as}%
+%<trace>     \showbox\@cclv
+%<trace>     \the\FN@tr@output
+%<trace>     \message{Returning from regular output with
+%<trace>     \ifnum\lastnodetype<\z@
+%<trace>       empty vertical list.\else vlist:}}%
+%<trace>   \showbox\z@
+%<trace>   \unvbox\z@{{\fi}}}\else\the\FN@tr@output\fi}
+%<trace> \let\output\FN@tr@output
+%    \end{macrocode}
+% If the footnote type ``default'' has not been declared by the time
+% the document starts, we do so at the start of the document.
+% Unfortunately, by this time the initialization code in |manyfoot|'s
+% own \cmd{\AtBeginDocument} hook has already run, so we manually run
+% the initialization hook just for the command we inserted ourselves.
+%    \begin{macrocode}
+\def\FN@maybestart#1#2#3{\ifx#3\relax
+  \csname MFL@start#1\endcsname{#2}\fi#3}
+\@onlypreamble\FN@maybestart
+\AtBeginDocument{\@ifundefined{footinsdefault}%
+  {\DeclareNewFootnote[plain]{default}%
+    {\let\@elt\FN@maybestart
+      \MFL@list\relax}}{}%
+  \let\c@footnote\c@footnotedefault
+  \let\thefootnote\thefootnotedefault
+  \def\thefootnotedefault{\thefootnote}%
+}
+%    \end{macrocode}
+% And since LaTeX's macros are inferior to our own (and would probably
+% not match too well), we reroot them to the default footnote style.
+%    \begin{macrocode}
+\def\footnote{\footnotedefault}
+\def\footnotemark{\footnotemarkdefault}
+\def\footnotetext{\footnotetextdefault}
+%</style>
+%    \end{macrocode}
+%
+% \section{Various driver files}
+% The installer, in case it is missing.  If it is to be used via
+% |make|, we don't specify an installation path, since
+% \begin{quote}
+%   |make install|
+% \end{quote}
+% is supposed to cater for the installation itself.
+%    \begin{macrocode}
+%<installer> \input docstrip
+%<installer&make> \askforoverwritefalse
+%<installer> \generate{
+%<installer>    \file{bigfoot.drv}{\from{bigfoot.dtx}{driver}}
+%<installer>    \file{perpage.drv}{\from{perpage.dtx}{driver}}
+%<installer>    \file{suffix.drv}{\from{suffix.dtx}{driver}}
+%<installer&!make>    \usedir{tex/latex/bigfoot}
+%<installer>    \file{bigfoot.sty}{\from{bigfoot.dtx}{style}}
+%<installer>    \file{perpage.sty}{\from{perpage.dtx}{style}}
+%<installer>    \file{suffix.sty}{\from{suffix.dtx}{style}}
+%<installer> }
+%<installer> \endbatchfile
+%    \end{macrocode}
+% \Finale
+% \endinput
+% Local Variables:
+% mode: doctex
+% TeX-master: "bigfoot.drv"
+% End:
-- 
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