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% texinfo.tex -- TeX macros to handle Texinfo files.
%
% Load plain if necessary, i.e., if running under initex.
\expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
%
\def\texinfoversion{2000-12-12.07}
%
% Copyright (C) 1985, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 2000
% Free Software Foundation, Inc.
%
% This texinfo.tex file 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, or (at
% your option) any later version.
%
% This texinfo.tex file 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 texinfo.tex file; see the file COPYING.  If not, write
% to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
% Boston, MA 02111-1307, USA.
%
% In other words, you are welcome to use, share and improve this program.
% You are forbidden to forbid anyone else to use, share and improve
% what you give them.   Help stamp out software-hoarding!
%
% Please try the latest version of texinfo.tex before submitting bug
% reports; you can get the latest version from:
%   ftp://ftp.gnu.org/gnu/texinfo.tex
%   (and all GNU mirrors, see http://www.gnu.org/order/ftp.html)
%   ftp://texinfo.org/tex/texinfo.tex
%   ftp://us.ctan.org/macros/texinfo/texinfo.tex
%   (and all CTAN mirrors, finger ctan@us.ctan.org for a list).
%   /home/gd/gnu/doc/texinfo.tex on the GNU machines.
% The texinfo.tex in any given Texinfo distribution could well be out
% of date, so if that's what you're using, please check.
% Texinfo has a small home page at http://texinfo.org/.
%
% Send bug reports to bug-texinfo@gnu.org.  Please include including a
% complete document in each bug report with which we can reproduce the
% problem.  Patches are, of course, greatly appreciated.
%
% To process a Texinfo manual with TeX, it's most reliable to use the
% texi2dvi shell script that comes with the distribution.  For a simple
% manual foo.texi, however, you can get away with this:
%   tex foo.texi
%   texindex foo.??
%   tex foo.texi
%   tex foo.texi
%   dvips foo.dvi -o # or whatever, to process the dvi file; this makes foo.ps.
% The extra runs of TeX get the cross-reference information correct.
% Sometimes one run after texindex suffices, and sometimes you need more
% than two; texi2dvi does it as many times as necessary.
%
% It is possible to adapt texinfo.tex for other languages.  You can get
% the existing language-specific files from ftp://ftp.gnu.org/gnu/texinfo/.

\message{Loading texinfo [version \texinfoversion]:}

% If in a .fmt file, print the version number
% and turn on active characters that we couldn't do earlier because
% they might have appeared in the input file name.
\everyjob{\message{[Texinfo version \texinfoversion]}%
  \catcode`+=\active \catcode`\_=\active}

% Save some parts of plain tex whose names we will redefine.
\let\ptexb=\b
\let\ptexbullet=\bullet
\let\ptexc=\c
\let\ptexcomma=\,
\let\ptexdot=\.
\let\ptexdots=\dots
\let\ptexend=\end
\let\ptexequiv=\equiv
\let\ptexexclam=\!
\let\ptexi=\i
\let\ptexlbrace=\{
\let\ptexrbrace=\}
\let\ptexstar=\*
\let\ptext=\t

% We never want plain's outer \+ definition in Texinfo.
% For @tex, we can use \tabalign.
\let\+ = \relax

\message{Basics,}
\chardef\other=12

% If this character appears in an error message or help string, it
% starts a new line in the output.
\newlinechar = `^^J

% Set up fixed words for English if not already set.
\ifx\putwordAppendix\undefined  \gdef\putwordAppendix{Appendix}\fi
\ifx\putwordChapter\undefined   \gdef\putwordChapter{Chapter}\fi
\ifx\putwordfile\undefined      \gdef\putwordfile{file}\fi
\ifx\putwordin\undefined        \gdef\putwordin{in}\fi
\ifx\putwordIndexIsEmpty\undefined     \gdef\putwordIndexIsEmpty{(Index is empty)}\fi
\ifx\putwordIndexNonexistent\undefined \gdef\putwordIndexNonexistent{(Index is nonexistent)}\fi
\ifx\putwordInfo\undefined      \gdef\putwordInfo{Info}\fi
\ifx\putwordInstanceVariableof\undefined \gdef\putwordInstanceVariableof{Instance Variable of}\fi
\ifx\putwordMethodon\undefined  \gdef\putwordMethodon{Method on}\fi
\ifx\putwordNoTitle\undefined   \gdef\putwordNoTitle{No Title}\fi
\ifx\putwordof\undefined        \gdef\putwordof{of}\fi
\ifx\putwordon\undefined        \gdef\putwordon{on}\fi
\ifx\putwordpage\undefined      \gdef\putwordpage{page}\fi
\ifx\putwordsection\undefined   \gdef\putwordsection{section}\fi
\ifx\putwordSection\undefined   \gdef\putwordSection{Section}\fi
\ifx\putwordsee\undefined       \gdef\putwordsee{see}\fi
\ifx\putwordSee\undefined       \gdef\putwordSee{See}\fi
\ifx\putwordShortTOC\undefined  \gdef\putwordShortTOC{Short Contents}\fi
\ifx\putwordTOC\undefined       \gdef\putwordTOC{Table of Contents}\fi
%
\ifx\putwordMJan\undefined \gdef\putwordMJan{January}\fi
\ifx\putwordMFeb\undefined \gdef\putwordMFeb{February}\fi
\ifx\putwordMMar\undefined \gdef\putwordMMar{March}\fi
\ifx\putwordMApr\undefined \gdef\putwordMApr{April}\fi
\ifx\putwordMMay\undefined \gdef\putwordMMay{May}\fi
\ifx\putwordMJun\undefined \gdef\putwordMJun{June}\fi
\ifx\putwordMJul\undefined \gdef\putwordMJul{July}\fi
\ifx\putwordMAug\undefined \gdef\putwordMAug{August}\fi
\ifx\putwordMSep\undefined \gdef\putwordMSep{September}\fi
\ifx\putwordMOct\undefined \gdef\putwordMOct{October}\fi
\ifx\putwordMNov\undefined \gdef\putwordMNov{November}\fi
\ifx\putwordMDec\undefined \gdef\putwordMDec{December}\fi
%
\ifx\putwordDefmac\undefined    \gdef\putwordDefmac{Macro}\fi
\ifx\putwordDefspec\undefined   \gdef\putwordDefspec{Special Form}\fi
\ifx\putwordDefvar\undefined    \gdef\putwordDefvar{Variable}\fi
\ifx\putwordDefopt\undefined    \gdef\putwordDefopt{User Option}\fi
\ifx\putwordDeftypevar\undefined\gdef\putwordDeftypevar{Variable}\fi
\ifx\putwordDeffunc\undefined   \gdef\putwordDeffunc{Function}\fi
\ifx\putwordDeftypefun\undefined\gdef\putwordDeftypefun{Function}\fi

% Ignore a token.
%
\def\gobble#1{}

\hyphenation{ap-pen-dix}
\hyphenation{mini-buf-fer mini-buf-fers}
\hyphenation{eshell}
\hyphenation{white-space}

% Margin to add to right of even pages, to left of odd pages.
\newdimen \bindingoffset
\newdimen \normaloffset
\newdimen\pagewidth \newdimen\pageheight

% Sometimes it is convenient to have everything in the transcript file
% and nothing on the terminal.  We don't just call \tracingall here,
% since that produces some useless output on the terminal.
%
\def\gloggingall{\begingroup \globaldefs = 1 \loggingall \endgroup}%
\ifx\eTeXversion\undefined
\def\loggingall{\tracingcommands2 \tracingstats2
   \tracingpages1 \tracingoutput1 \tracinglostchars1
   \tracingmacros2 \tracingparagraphs1 \tracingrestores1
   \showboxbreadth\maxdimen\showboxdepth\maxdimen
}%
\else
\def\loggingall{\tracingcommands3 \tracingstats2
   \tracingpages1 \tracingoutput1 \tracinglostchars1
   \tracingmacros2 \tracingparagraphs1 \tracingrestores1
   \tracingscantokens1 \tracingassigns1 \tracingifs1
   \tracinggroups1 \tracingnesting2
   \showboxbreadth\maxdimen\showboxdepth\maxdimen
}%
\fi

% For @cropmarks command.
% Do @cropmarks to get crop marks.
%
\newif\ifcropmarks
\let\cropmarks = \cropmarkstrue
%
% Dimensions to add cropmarks at corners.
% Added by P. A. MacKay, 12 Nov. 1986
%
\newdimen\outerhsize \newdimen\outervsize % set by the paper size routines
\newdimen\cornerlong  \cornerlong=1pc
\newdimen\cornerthick \cornerthick=.3pt
\newdimen\topandbottommargin \topandbottommargin=.75in

% Main output routine.
\chardef\PAGE = 255
\output = {\onepageout{\pagecontents\PAGE}}

\newbox\headlinebox
\newbox\footlinebox

% \onepageout takes a vbox as an argument.  Note that \pagecontents
% does insertions, but you have to call it yourself.
\def\onepageout#1{%
  \ifcropmarks \hoffset=0pt \else \hoffset=\normaloffset \fi
  %
  \ifodd\pageno  \advance\hoffset by \bindingoffset
  \else \advance\hoffset by -\bindingoffset\fi
  %
  % Do this outside of the \shipout so @code etc. will be expanded in
  % the headline as they should be, not taken literally (outputting ''code).
  \setbox\headlinebox = \vbox{\let\hsize=\pagewidth \makeheadline}%
  \setbox\footlinebox = \vbox{\let\hsize=\pagewidth \makefootline}%
  %
  {%
    % Have to do this stuff outside the \shipout because we want it to
    % take effect in \write's, yet the group defined by the \vbox ends
    % before the \shipout runs.
    %
    \escapechar = `\\     % use backslash in output files.
    \indexdummies         % don't expand commands in the output.
    \normalturnoffactive  % \ in index entries must not stay \, e.g., if
                   % the page break happens to be in the middle of an example.
    \shipout\vbox{%
      % Do this early so pdf references go to the beginning of the page.
      \ifpdfmakepagedest \pdfmkdest{\the\pageno} \fi
      %
      \ifcropmarks \vbox to \outervsize\bgroup
        \hsize = \outerhsize
        \vskip-\topandbottommargin
        \vtop to0pt{%
          \line{\ewtop\hfil\ewtop}%
          \nointerlineskip
          \line{%
            \vbox{\moveleft\cornerthick\nstop}%
            \hfill
            \vbox{\moveright\cornerthick\nstop}%
          }%
          \vss}%
        \vskip\topandbottommargin
        \line\bgroup
          \hfil % center the page within the outer (page) hsize.
          \ifodd\pageno\hskip\bindingoffset\fi
          \vbox\bgroup
      \fi
      %
      \unvbox\headlinebox
      \pagebody{#1}%
      \ifdim\ht\footlinebox > 0pt
        % Only leave this space if the footline is nonempty.
        % (We lessened \vsize for it in \oddfootingxxx.)
        % The \baselineskip=24pt in plain's \makefootline has no effect.
        \vskip 2\baselineskip
        \unvbox\footlinebox
      \fi
      %
      \ifcropmarks
          \egroup % end of \vbox\bgroup
        \hfil\egroup % end of (centering) \line\bgroup
        \vskip\topandbottommargin plus1fill minus1fill
        \boxmaxdepth = \cornerthick
        \vbox to0pt{\vss
          \line{%
            \vbox{\moveleft\cornerthick\nsbot}%
            \hfill
            \vbox{\moveright\cornerthick\nsbot}%
          }%
          \nointerlineskip
          \line{\ewbot\hfil\ewbot}%
        }%
      \egroup % \vbox from first cropmarks clause
      \fi
    }% end of \shipout\vbox
  }% end of group with \turnoffactive
  \advancepageno
  \ifnum\outputpenalty>-20000 \else\dosupereject\fi
}

\newinsert\margin \dimen\margin=\maxdimen

\def\pagebody#1{\vbox to\pageheight{\boxmaxdepth=\maxdepth #1}}
{\catcode`\@ =11
\gdef\pagecontents#1{\ifvoid\topins\else\unvbox\topins\fi
% marginal hacks, juha@viisa.uucp (Juha Takala)
\ifvoid\margin\else % marginal info is present
  \rlap{\kern\hsize\vbox to\z@{\kern1pt\box\margin \vss}}\fi
\dimen@=\dp#1 \unvbox#1
\ifvoid\footins\else\vskip\skip\footins\footnoterule \unvbox\footins\fi
\ifr@ggedbottom \kern-\dimen@ \vfil \fi}
}

% Here are the rules for the cropmarks.  Note that they are
% offset so that the space between them is truly \outerhsize or \outervsize
% (P. A. MacKay, 12 November, 1986)
%
\def\ewtop{\vrule height\cornerthick depth0pt width\cornerlong}
\def\nstop{\vbox
  {\hrule height\cornerthick depth\cornerlong width\cornerthick}}
\def\ewbot{\vrule height0pt depth\cornerthick width\cornerlong}
\def\nsbot{\vbox
  {\hrule height\cornerlong depth\cornerthick width\cornerthick}}

% Parse an argument, then pass it to #1.  The argument is the rest of
% the input line (except we remove a trailing comment).  #1 should be a
% macro which expects an ordinary undelimited TeX argument.
%
\def\parsearg#1{%
  \let\next = #1%
  \begingroup
    \obeylines
    \futurelet\temp\parseargx
}

% If the next token is an obeyed space (from an @example environment or
% the like), remove it and recurse.  Otherwise, we're done.
\def\parseargx{%
  % \obeyedspace is defined far below, after the definition of \sepspaces.
  \ifx\obeyedspace\temp
    \expandafter\parseargdiscardspace
  \else
    \expandafter\parseargline
  \fi
}

% Remove a single space (as the delimiter token to the macro call).
{\obeyspaces %
 \gdef\parseargdiscardspace {\futurelet\temp\parseargx}}

{\obeylines %
  \gdef\parseargline#1^^M{%
    \endgroup % End of the group started in \parsearg.
    %
    % First remove any @c comment, then any @comment.
    % Result of each macro is put in \toks0.
    \argremovec #1\c\relax %
    \expandafter\argremovecomment \the\toks0 \comment\relax %
    %
    % Call the caller's macro, saved as \next in \parsearg.
    \expandafter\next\expandafter{\the\toks0}%
  }%
}

% Since all \c{,omment} does is throw away the argument, we can let TeX
% do that for us.  The \relax here is matched by the \relax in the call
% in \parseargline; it could be more or less anything, its purpose is
% just to delimit the argument to the \c.
\def\argremovec#1\c#2\relax{\toks0 = {#1}}
\def\argremovecomment#1\comment#2\relax{\toks0 = {#1}}

% \argremovec{,omment} might leave us with trailing spaces, though; e.g.,
%    @end itemize  @c foo
% will have two active spaces as part of the argument with the
% `itemize'.  Here we remove all active spaces from #1, and assign the
% result to \toks0.
%
% This loses if there are any *other* active characters besides spaces
% in the argument -- _ ^ +, for example -- since they get expanded.
% Fortunately, Texinfo does not define any such commands.  (If it ever
% does, the catcode of the characters in questionwill have to be changed
% here.)  But this means we cannot call \removeactivespaces as part of
% \argremovec{,omment}, since @c uses \parsearg, and thus the argument
% that \parsearg gets might well have any character at all in it.
%
\def\removeactivespaces#1{%
  \begingroup
    \ignoreactivespaces
    \edef\temp{#1}%
    \global\toks0 = \expandafter{\temp}%
  \endgroup
}

% Change the active space to expand to nothing.
%
\begingroup
  \obeyspaces
  \gdef\ignoreactivespaces{\obeyspaces\let =\empty}
\endgroup


\def\flushcr{\ifx\par\lisppar \def\next##1{}\else \let\next=\relax \fi \next}

%% These are used to keep @begin/@end levels from running away
%% Call \inENV within environments (after a \begingroup)
\newif\ifENV \ENVfalse \def\inENV{\ifENV\relax\else\ENVtrue\fi}
\def\ENVcheck{%
\ifENV\errmessage{Still within an environment; press RETURN to continue}
\endgroup\fi} % This is not perfect, but it should reduce lossage

% @begin foo  is the same as @foo, for now.
\newhelp\EMsimple{Press RETURN to continue.}

\outer\def\begin{\parsearg\beginxxx}

\def\beginxxx #1{%
\expandafter\ifx\csname #1\endcsname\relax
{\errhelp=\EMsimple \errmessage{Undefined command @begin #1}}\else
\csname #1\endcsname\fi}

% @end foo executes the definition of \Efoo.
%
\def\end{\parsearg\endxxx}
\def\endxxx #1{%
  \removeactivespaces{#1}%
  \edef\endthing{\the\toks0}%
  %
  \expandafter\ifx\csname E\endthing\endcsname\relax
    \expandafter\ifx\csname \endthing\endcsname\relax
      % There's no \foo, i.e., no ``environment'' foo.
      \errhelp = \EMsimple
      \errmessage{Undefined command `@end \endthing'}%
    \else
      \unmatchedenderror\endthing
    \fi
  \else
    % Everything's ok; the right environment has been started.
    \csname E\endthing\endcsname
  \fi
}

% There is an environment #1, but it hasn't been started.  Give an error.
%
\def\unmatchedenderror#1{%
  \errhelp = \EMsimple
  \errmessage{This `@end #1' doesn't have a matching `@#1'}%
}

% Define the control sequence \E#1 to give an unmatched @end error.
%
\def\defineunmatchedend#1{%
  \expandafter\def\csname E#1\endcsname{\unmatchedenderror{#1}}%
}


% Single-spacing is done by various environments (specifically, in
% \nonfillstart and \quotations).
\newskip\singlespaceskip \singlespaceskip = 12.5pt
\def\singlespace{%
  % Why was this kern here?  It messes up equalizing space above and below
  % environments.  --karl, 6may93
  %{\advance \baselineskip by -\singlespaceskip
  %\kern \baselineskip}%
  \setleading \singlespaceskip
}

%% Simple single-character @ commands

% @@ prints an @
% Kludge this until the fonts are right (grr).
\def\@{{\tt\char64}}

% This is turned off because it was never documented
% and you can use @w{...} around a quote to suppress ligatures.
%% Define @` and @' to be the same as ` and '
%% but suppressing ligatures.
%\def\`{{`}}
%\def\'{{'}}

% Used to generate quoted braces.
\def\mylbrace {{\tt\char123}}
\def\myrbrace {{\tt\char125}}
\let\{=\mylbrace
\let\}=\myrbrace
\begingroup
  % Definitions to produce actual \{ & \} command in an index.
  \catcode`\{ = 12 \catcode`\} = 12
  \catcode`\[ = 1 \catcode`\] = 2
  \catcode`\@ = 0 \catcode`\\ = 12
  @gdef@lbracecmd[\{]%
  @gdef@rbracecmd[\}]%
@endgroup

% Accents: @, @dotaccent @ringaccent @ubaraccent @udotaccent
% Others are defined by plain TeX: @` @' @" @^ @~ @= @v @H.
\let\, = \c
\let\dotaccent = \.
\def\ringaccent#1{{\accent23 #1}}
\let\tieaccent = \t
\let\ubaraccent = \b
\let\udotaccent = \d

% Other special characters: @questiondown @exclamdown
% Plain TeX defines: @AA @AE @O @OE @L (and lowercase versions) @ss.
\def\questiondown{?`}
\def\exclamdown{!`}

% Dotless i and dotless j, used for accents.
\def\imacro{i}
\def\jmacro{j}
\def\dotless#1{%
  \def\temp{#1}%
  \ifx\temp\imacro \ptexi
  \else\ifx\temp\jmacro \j
  \else \errmessage{@dotless can be used only with i or j}%
  \fi\fi
}

% Be sure we're in horizontal mode when doing a tie, since we make space
% equivalent to this in @example-like environments. Otherwise, a space
% at the beginning of a line will start with \penalty -- and
% since \penalty is valid in vertical mode, we'd end up putting the
% penalty on the vertical list instead of in the new paragraph.
{\catcode`@ = 11
 % Avoid using \@M directly, because that causes trouble
 % if the definition is written into an index file.
 \global\let\tiepenalty = \@M
 \gdef\tie{\leavevmode\penalty\tiepenalty\ }
}

% @: forces normal size whitespace following.
\def\:{\spacefactor=1000 }

% @* forces a line break.
\def\*{\hfil\break\hbox{}\ignorespaces}

% @. is an end-of-sentence period.
\def\.{.\spacefactor=3000 }

% @! is an end-of-sentence bang.
\def\!{!\spacefactor=3000 }

% @? is an end-of-sentence query.
\def\?{?\spacefactor=3000 }

% @w prevents a word break.  Without the \leavevmode, @w at the
% beginning of a paragraph, when TeX is still in vertical mode, would
% produce a whole line of output instead of starting the paragraph.
\def\w#1{\leavevmode\hbox{#1}}

% @group ... @end group forces ... to be all on one page, by enclosing
% it in a TeX vbox.  We use \vtop instead of \vbox to construct the box
% to keep its height that of a normal line.  According to the rules for
% \topskip (p.114 of the TeXbook), the glue inserted is
% max (\topskip - \ht (first item), 0).  If that height is large,
% therefore, no glue is inserted, and the space between the headline and
% the text is small, which looks bad.
%
\def\group{\begingroup
  \ifnum\catcode13=\active \else
    \errhelp = \groupinvalidhelp
    \errmessage{@group invalid in context where filling is enabled}%
  \fi
  %
  % The \vtop we start below produces a box with normal height and large
  % depth; thus, TeX puts \baselineskip glue before it, and (when the
  % next line of text is done) \lineskip glue after it.  (See p.82 of
  % the TeXbook.)  Thus, space below is not quite equal to space
  % above.  But it's pretty close.
  \def\Egroup{%
    \egroup           % End the \vtop.
    \endgroup         % End the \group.
  }%
  %
  \vtop\bgroup
    % We have to put a strut on the last line in case the @group is in
    % the midst of an example, rather than completely enclosing it.
    % Otherwise, the interline space between the last line of the group
    % and the first line afterwards is too small.  But we can't put the
    % strut in \Egroup, since there it would be on a line by itself.
    % Hence this just inserts a strut at the beginning of each line.
    \everypar = {\strut}%
    %
    % Since we have a strut on every line, we don't need any of TeX's
    % normal interline spacing.
    \offinterlineskip
    %
    % OK, but now we have to do something about blank
    % lines in the input in @example-like environments, which normally
    % just turn into \lisppar, which will insert no space now that we've
    % turned off the interline space.  Simplest is to make them be an
    % empty paragraph.
    \ifx\par\lisppar
      \edef\par{\leavevmode \par}%
      %
      % Reset ^^M's definition to new definition of \par.
      \obeylines
    \fi
    %
    % Do @comment since we are called inside an environment such as
    % @example, where each end-of-line in the input causes an
    % end-of-line in the output.  We don't want the end-of-line after
    % the `@group' to put extra space in the output.  Since @group
    % should appear on a line by itself (according to the Texinfo
    % manual), we don't worry about eating any user text.
    \comment
}
%
% TeX puts in an \escapechar (i.e., `@') at the beginning of the help
% message, so this ends up printing `@group can only ...'.
%
\newhelp\groupinvalidhelp{%
group can only be used in environments such as @example,^^J%
where each line of input produces a line of output.}

% @need space-in-mils
% forces a page break if there is not space-in-mils remaining.

\newdimen\mil  \mil=0.001in

\def\need{\parsearg\needx}

% Old definition--didn't work.
%\def\needx #1{\par %
%% This method tries to make TeX break the page naturally
%% if the depth of the box does not fit.
%{\baselineskip=0pt%
%\vtop to #1\mil{\vfil}\kern -#1\mil\nobreak
%\prevdepth=-1000pt
%}}

\def\needx#1{%
  % Ensure vertical mode, so we don't make a big box in the middle of a
  % paragraph.
  \par
  %
  % If the @need value is less than one line space, it's useless.
  \dimen0 = #1\mil
  \dimen2 = \ht\strutbox
  \advance\dimen2 by \dp\strutbox
  \ifdim\dimen0 > \dimen2
    %
    % Do a \strut just to make the height of this box be normal, so the
    % normal leading is inserted relative to the preceding line.
    % And a page break here is fine.
    \vtop to #1\mil{\strut\vfil}%
    %
    % TeX does not even consider page breaks if a penalty added to the
    % main vertical list is 10000 or more.  But in order to see if the
    % empty box we just added fits on the page, we must make it consider
    % page breaks.  On the other hand, we don't want to actually break the
    % page after the empty box.  So we use a penalty of 9999.
    %
    % There is an extremely small chance that TeX will actually break the
    % page at this \penalty, if there are no other feasible breakpoints in
    % sight.  (If the user is using lots of big @group commands, which
    % almost-but-not-quite fill up a page, TeX will have a hard time doing
    % good page breaking, for example.)  However, I could not construct an
    % example where a page broke at this \penalty; if it happens in a real
    % document, then we can reconsider our strategy.
    \penalty9999
    %
    % Back up by the size of the box, whether we did a page break or not.
    \kern -#1\mil
    %
    % Do not allow a page break right after this kern.
    \nobreak
  \fi
}

% @br   forces paragraph break

\let\br = \par

% @dots{} output an ellipsis using the current font.
% We do .5em per period so that it has the same spacing in a typewriter
% font as three actual period characters.
%
\def\dots{%
  \leavevmode
  \hbox to 1.5em{%
    \hskip 0pt plus 0.25fil minus 0.25fil
    .\hss.\hss.%
    \hskip 0pt plus 0.5fil minus 0.5fil
  }%
}

% @enddots{} is an end-of-sentence ellipsis.
%
\def\enddots{%
  \leavevmode
  \hbox to 2em{%
    \hskip 0pt plus 0.25fil minus 0.25fil
    .\hss.\hss.\hss.%
    \hskip 0pt plus 0.5fil minus 0.5fil
  }%
  \spacefactor=3000
}


% @page    forces the start of a new page
%
\def\page{\par\vfill\supereject}

% @exdent text....
% outputs text on separate line in roman font, starting at standard page margin

% This records the amount of indent in the innermost environment.
% That's how much \exdent should take out.
\newskip\exdentamount

% This defn is used inside fill environments such as @defun.
\def\exdent{\parsearg\exdentyyy}
\def\exdentyyy #1{{\hfil\break\hbox{\kern -\exdentamount{\rm#1}}\hfil\break}}

% This defn is used inside nofill environments such as @example.
\def\nofillexdent{\parsearg\nofillexdentyyy}
\def\nofillexdentyyy #1{{\advance \leftskip by -\exdentamount
\leftline{\hskip\leftskip{\rm#1}}}}

% @inmargin{WHICH}{TEXT} puts TEXT in the WHICH margin next to the current
% paragraph.  For more general purposes, use the \margin insertion
% class.  WHICH is `l' or `r'.
%
\newskip\inmarginspacing \inmarginspacing=1cm
\def\strutdepth{\dp\strutbox}
%
\def\doinmargin#1#2{\strut\vadjust{%
  \nobreak
  \kern-\strutdepth
  \vtop to \strutdepth{%
    \baselineskip=\strutdepth
    \vss
    % if you have multiple lines of stuff to put here, you'll need to
    % make the vbox yourself of the appropriate size.
    \ifx#1l%
      \llap{\ignorespaces #2\hskip\inmarginspacing}%
    \else
      \rlap{\hskip\hsize \hskip\inmarginspacing \ignorespaces #2}%
    \fi
    \null
  }%
}}
\def\inleftmargin{\doinmargin l}
\def\inrightmargin{\doinmargin r}
%
% @inmargin{TEXT [, RIGHT-TEXT]}
% (if RIGHT-TEXT is given, use TEXT for left page, RIGHT-TEXT for right;
% else use TEXT for both).
% 
\def\inmargin#1{\parseinmargin #1,,\finish}
\def\parseinmargin#1,#2,#3\finish{% not perfect, but better than nothing.
  \setbox0 = \hbox{\ignorespaces #2}% 
  \ifdim\wd0 > 0pt
    \def\lefttext{#1}%  have both texts
    \def\righttext{#2}%
  \else
    \def\lefttext{#1}%  have only one text
    \def\righttext{#1}%
  \fi
  %
  \ifodd\pageno
    \def\temp{\inrightmargin\righttext}% odd page -> outside is right margin
  \else
    \def\temp{\inleftmargin\lefttext}%
  \fi
  \temp
}

% @include file    insert text of that file as input.
% Allow normal characters that  we make active in the argument (a file name).
\def\include{\begingroup
  \catcode`\\=12
  \catcode`~=12
  \catcode`^=12
  \catcode`_=12
  \catcode`|=12
  \catcode`<=12
  \catcode`>=12
  \catcode`+=12
  \parsearg\includezzz}
% Restore active chars for included file.
\def\includezzz#1{\endgroup\begingroup
  % Read the included file in a group so nested @include's work.
  \def\thisfile{#1}%
  \input\thisfile
\endgroup}

\def\thisfile{}

% @center line   outputs that line, centered

\def\center{\parsearg\centerzzz}
\def\centerzzz #1{{\advance\hsize by -\leftskip
\advance\hsize by -\rightskip
\centerline{#1}}}

% @sp n   outputs n lines of vertical space

\def\sp{\parsearg\spxxx}
\def\spxxx #1{\vskip #1\baselineskip}

% @comment ...line which is ignored...
% @c is the same as @comment
% @ignore ... @end ignore  is another way to write a comment

\def\comment{\begingroup \catcode`\^^M=\other%
\catcode`\@=\other \catcode`\{=\other \catcode`\}=\other%
\commentxxx}
{\catcode`\^^M=\other \gdef\commentxxx#1^^M{\endgroup}}

\let\c=\comment

% @paragraphindent NCHARS
% We'll use ems for NCHARS, close enough.
% We cannot implement @paragraphindent asis, though.
% 
\def\asisword{asis} % no translation, these are keywords
\def\noneword{none}
%
\def\paragraphindent{\parsearg\doparagraphindent}
\def\doparagraphindent#1{%
  \def\temp{#1}%
  \ifx\temp\asisword
  \else
    \ifx\temp\noneword
      \defaultparindent = 0pt
    \else
      \defaultparindent = #1em
    \fi
  \fi
  \parindent = \defaultparindent
}

% @exampleindent NCHARS
% We'll use ems for NCHARS like @paragraphindent.
% It seems @exampleindent asis isn't necessary, but
% I preserve it to make it similar to @paragraphindent.
\def\exampleindent{\parsearg\doexampleindent}
\def\doexampleindent#1{%
  \def\temp{#1}%
  \ifx\temp\asisword
  \else
    \ifx\temp\noneword
      \lispnarrowing = 0pt
    \else
      \lispnarrowing = #1em
    \fi
  \fi
}

% @asis just yields its argument.  Used with @table, for example.
%
\def\asis#1{#1}

% @math means output in math mode.
% We don't use $'s directly in the definition of \math because control
% sequences like \math are expanded when the toc file is written.  Then,
% we read the toc file back, the $'s will be normal characters (as they
% should be, according to the definition of Texinfo).  So we must use a
% control sequence to switch into and out of math mode.
%
% This isn't quite enough for @math to work properly in indices, but it
% seems unlikely it will ever be needed there.
%
\let\implicitmath = $
\def\math#1{\implicitmath #1\implicitmath}

% @bullet and @minus need the same treatment as @math, just above.
\def\bullet{\implicitmath\ptexbullet\implicitmath}
\def\minus{\implicitmath-\implicitmath}

% @refill is a no-op.
\let\refill=\relax

% If working on a large document in chapters, it is convenient to
% be able to disable indexing, cross-referencing, and contents, for test runs.
% This is done with @novalidate (before @setfilename).
%
\newif\iflinks \linkstrue % by default we want the aux files.
\let\novalidate = \linksfalse

% @setfilename is done at the beginning of every texinfo file.
% So open here the files we need to have open while reading the input.
% This makes it possible to make a .fmt file for texinfo.
\def\setfilename{%
   \iflinks
     \readauxfile
   \fi % \openindices needs to do some work in any case.
   \openindices
   \fixbackslash  % Turn off hack to swallow `\input texinfo'.
   \global\let\setfilename=\comment % Ignore extra @setfilename cmds.
   %
   % If texinfo.cnf is present on the system, read it.
   % Useful for site-wide @afourpaper, etc.
   % Just to be on the safe side, close the input stream before the \input.
   \openin 1 texinfo.cnf
   \ifeof1 \let\temp=\relax \else \def\temp{\input texinfo.cnf }\fi
   \closein1
   \temp
   %
   \comment % Ignore the actual filename.
}

% Called from \setfilename.
%
\def\openindices{%
  \newindex{cp}%
  \newcodeindex{fn}%
  \newcodeindex{vr}%
  \newcodeindex{tp}%
  \newcodeindex{ky}%
  \newcodeindex{pg}%
}

% @bye.
\outer\def\bye{\pagealignmacro\tracingstats=1\ptexend}


\message{pdf,}
% adobe `portable' document format
\newcount\tempnum
\newcount\lnkcount
\newtoks\filename
\newcount\filenamelength
\newcount\pgn
\newtoks\toksA
\newtoks\toksB
\newtoks\toksC
\newtoks\toksD
\newbox\boxA
\newcount\countA
\newif\ifpdf
\newif\ifpdfmakepagedest

\ifx\pdfoutput\undefined
  \pdffalse
  \let\pdfmkdest = \gobble
  \let\pdfurl = \gobble
  \let\endlink = \relax
  \let\linkcolor = \relax
  \let\pdfmakeoutlines = \relax
\else
  \pdftrue
  \pdfoutput = 1
  \input pdfcolor
  \def\dopdfimage#1#2#3{%
    \def\imagewidth{#2}%
    \def\imageheight{#3}%
    \ifnum\pdftexversion < 14
      \pdfimage
    \else
      \pdfximage
    \fi
      \ifx\empty\imagewidth\else width \imagewidth \fi
      \ifx\empty\imageheight\else height \imageheight \fi
      {#1.pdf}%
    \ifnum\pdftexversion < 14 \else
      \pdfrefximage \pdflastximage
    \fi}
  \def\pdfmkdest#1{\pdfdest name{#1@} xyz}
  \def\pdfmkpgn#1{#1@}
  \let\linkcolor = \Blue  % was Cyan, but that seems light?
  \def\endlink{\Black\pdfendlink}
  % Adding outlines to PDF; macros for calculating structure of outlines
  % come from Petr Olsak
  \def\expnumber#1{\expandafter\ifx\csname#1\endcsname\relax 0%
    \else \csname#1\endcsname \fi}
  \def\advancenumber#1{\tempnum=\expnumber{#1}\relax
    \advance\tempnum by1
    \expandafter\xdef\csname#1\endcsname{\the\tempnum}}
  \def\pdfmakeoutlines{{%
    \openin 1 \jobname.toc
    \ifeof 1\else\bgroup
      \closein 1 
      \indexnofonts
      \def\tt{}
      \let\_ = \normalunderscore
      % Thanh's hack / proper braces in bookmarks  
      \edef\mylbrace{\iftrue \string{\else}\fi}\let\{=\mylbrace
      \edef\myrbrace{\iffalse{\else\string}\fi}\let\}=\myrbrace
      %
      \def\chapentry ##1##2##3{}
      \def\unnumbchapentry ##1##2{}
      \def\secentry ##1##2##3##4{\advancenumber{chap##2}}
      \def\unnumbsecentry ##1##2{}
      \def\subsecentry ##1##2##3##4##5{\advancenumber{sec##2.##3}}
      \def\unnumbsubsecentry ##1##2{}
      \def\subsubsecentry ##1##2##3##4##5##6{\advancenumber{subsec##2.##3.##4}}
      \def\unnumbsubsubsecentry ##1##2{}
      \input \jobname.toc
      \def\chapentry ##1##2##3{%
        \pdfoutline goto name{\pdfmkpgn{##3}}count-\expnumber{chap##2}{##1}}
      \def\unnumbchapentry ##1##2{%
        \pdfoutline goto name{\pdfmkpgn{##2}}{##1}}
      \def\secentry ##1##2##3##4{%
        \pdfoutline goto name{\pdfmkpgn{##4}}count-\expnumber{sec##2.##3}{##1}}
      \def\unnumbsecentry ##1##2{%
        \pdfoutline goto name{\pdfmkpgn{##2}}{##1}}
      \def\subsecentry ##1##2##3##4##5{%
        \pdfoutline goto name{\pdfmkpgn{##5}}count-\expnumber{subsec##2.##3.##4}{##1}}
      \def\unnumbsubsecentry ##1##2{%
        \pdfoutline goto name{\pdfmkpgn{##2}}{##1}}
      \def\subsubsecentry ##1##2##3##4##5##6{%
        \pdfoutline goto name{\pdfmkpgn{##6}}{##1}}
      \def\unnumbsubsubsecentry ##1##2{%
        \pdfoutline goto name{\pdfmkpgn{##2}}{##1}}
      \input \jobname.toc
    \egroup\fi
  }}
  \def\makelinks #1,{%
    \def\params{#1}\def\E{END}%
    \ifx\params\E
      \let\nextmakelinks=\relax
    \else
      \let\nextmakelinks=\makelinks
      \ifnum\lnkcount>0,\fi
      \picknum{#1}%
      \startlink attr{/Border [0 0 0]} 
        goto name{\pdfmkpgn{\the\pgn}}%
      \linkcolor #1%
      \advance\lnkcount by 1%
      \endlink
    \fi
    \nextmakelinks
  }
  \def\picknum#1{\expandafter\pn#1}
  \def\pn#1{%
    \def\p{#1}%
    \ifx\p\lbrace
      \let\nextpn=\ppn
    \else
      \let\nextpn=\ppnn
      \def\first{#1}
    \fi
    \nextpn
  }
  \def\ppn#1{\pgn=#1\gobble}
  \def\ppnn{\pgn=\first}
  \def\pdfmklnk#1{\lnkcount=0\makelinks #1,END,}
  \def\addtokens#1#2{\edef\addtoks{\noexpand#1={\the#1#2}}\addtoks}
  \def\skipspaces#1{\def\PP{#1}\def\D{|}%
    \ifx\PP\D\let\nextsp\relax
    \else\let\nextsp\skipspaces
      \ifx\p\space\else\addtokens{\filename}{\PP}%
        \advance\filenamelength by 1
      \fi
    \fi
    \nextsp}
  \def\getfilename#1{\filenamelength=0\expandafter\skipspaces#1|\relax}
  \ifnum\pdftexversion < 14
    \let \startlink \pdfannotlink
  \else
    \let \startlink \pdfstartlink
  \fi
  \def\pdfurl#1{%
    \begingroup
      \normalturnoffactive\def\@{@}%
      \leavevmode\Red
      \startlink attr{/Border [0 0 0]}%
        user{/Subtype /Link /A << /S /URI /URI (#1) >>}%
        % #1
    \endgroup}
  \def\pdfgettoks#1.{\setbox\boxA=\hbox{\toksA={#1.}\toksB={}\maketoks}}
  \def\addtokens#1#2{\edef\addtoks{\noexpand#1={\the#1#2}}\addtoks}
  \def\adn#1{\addtokens{\toksC}{#1}\global\countA=1\let\next=\maketoks}
  \def\poptoks#1#2|ENDTOKS|{\let\first=#1\toksD={#1}\toksA={#2}}
  \def\maketoks{%
    \expandafter\poptoks\the\toksA|ENDTOKS|
    \ifx\first0\adn0
    \else\ifx\first1\adn1 \else\ifx\first2\adn2 \else\ifx\first3\adn3
    \else\ifx\first4\adn4 \else\ifx\first5\adn5 \else\ifx\first6\adn6
    \else\ifx\first7\adn7 \else\ifx\first8\adn8 \else\ifx\first9\adn9 
    \else
      \ifnum0=\countA\else\makelink\fi
      \ifx\first.\let\next=\done\else
        \let\next=\maketoks
        \addtokens{\toksB}{\the\toksD}
        \ifx\first,\addtokens{\toksB}{\space}\fi
      \fi
    \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi
    \next}
  \def\makelink{\addtokens{\toksB}%
    {\noexpand\pdflink{\the\toksC}}\toksC={}\global\countA=0}
  \def\pdflink#1{%
    \startlink attr{/Border [0 0 0]} goto name{\mkpgn{#1}}
    \linkcolor #1\endlink}
  \def\mkpgn#1{#1@} 
  \def\done{\edef\st{\global\noexpand\toksA={\the\toksB}}\st}
\fi % \ifx\pdfoutput


\message{fonts,}
% Font-change commands.

% Texinfo sort of supports the sans serif font style, which plain TeX does not.
% So we set up a \sf analogous to plain's \rm, etc.
\newfam\sffam
\def\sf{\fam=\sffam \tensf}
\let\li = \sf % Sometimes we call it \li, not \sf.

% We don't need math for this one.
\def\ttsl{\tenttsl}

% Use Computer Modern fonts at \magstephalf (11pt).
\newcount\mainmagstep
\mainmagstep=\magstephalf

% Set the font macro #1 to the font named #2, adding on the
% specified font prefix (normally `cm').
% #3 is the font's design size, #4 is a scale factor
\def\setfont#1#2#3#4{\font#1=\fontprefix#2#3 scaled #4}

% Use cm as the default font prefix.
% To specify the font prefix, you must define \fontprefix
% before you read in texinfo.tex.
\ifx\fontprefix\undefined
\def\fontprefix{cm}
\fi
% Support font families that don't use the same naming scheme as CM.
\def\rmshape{r}
\def\rmbshape{bx}               %where the normal face is bold
\def\bfshape{b}
\def\bxshape{bx}
\def\ttshape{tt}
\def\ttbshape{tt}
\def\ttslshape{sltt}
\def\itshape{ti}
\def\itbshape{bxti}
\def\slshape{sl}
\def\slbshape{bxsl}
\def\sfshape{ss}
\def\sfbshape{ss}
\def\scshape{csc}
\def\scbshape{csc}

\ifx\bigger\relax
\let\mainmagstep=\magstep1
\setfont\textrm\rmshape{12}{1000}
\setfont\texttt\ttshape{12}{1000}
\else
\setfont\textrm\rmshape{10}{\mainmagstep}
\setfont\texttt\ttshape{10}{\mainmagstep}
\fi
% Instead of cmb10, you many want to use cmbx10.
% cmbx10 is a prettier font on its own, but cmb10
% looks better when embedded in a line with cmr10.
\setfont\textbf\bfshape{10}{\mainmagstep}
\setfont\textit\itshape{10}{\mainmagstep}
\setfont\textsl\slshape{10}{\mainmagstep}
\setfont\textsf\sfshape{10}{\mainmagstep}
\setfont\textsc\scshape{10}{\mainmagstep}
\setfont\textttsl\ttslshape{10}{\mainmagstep}
\font\texti=cmmi10 scaled \mainmagstep
\font\textsy=cmsy10 scaled \mainmagstep

% A few fonts for @defun, etc.
\setfont\defbf\bxshape{10}{\magstep1} %was 1314
\setfont\deftt\ttshape{10}{\magstep1}
\def\df{\let\tentt=\deftt \let\tenbf = \defbf \bf}

% Fonts for indices, footnotes, small examples (9pt).
\setfont\smallrm\rmshape{9}{1000}
\setfont\smalltt\ttshape{9}{1000}
\setfont\smallbf\bfshape{10}{900}
\setfont\smallit\itshape{9}{1000}
\setfont\smallsl\slshape{9}{1000}
\setfont\smallsf\sfshape{9}{1000}
\setfont\smallsc\scshape{10}{900}
\setfont\smallttsl\ttslshape{10}{900}
\font\smalli=cmmi9
\font\smallsy=cmsy9

% Fonts for title page:
\setfont\titlerm\rmbshape{12}{\magstep3}
\setfont\titleit\itbshape{10}{\magstep4}
\setfont\titlesl\slbshape{10}{\magstep4}
\setfont\titlett\ttbshape{12}{\magstep3}
\setfont\titlettsl\ttslshape{10}{\magstep4}
\setfont\titlesf\sfbshape{17}{\magstep1}
\let\titlebf=\titlerm
\setfont\titlesc\scbshape{10}{\magstep4}
\font\titlei=cmmi12 scaled \magstep3
\font\titlesy=cmsy10 scaled \magstep4
\def\authorrm{\secrm}

% Chapter (and unnumbered) fonts (17.28pt).
\setfont\chaprm\rmbshape{12}{\magstep2}
\setfont\chapit\itbshape{10}{\magstep3}
\setfont\chapsl\slbshape{10}{\magstep3}
\setfont\chaptt\ttbshape{12}{\magstep2}
\setfont\chapttsl\ttslshape{10}{\magstep3}
\setfont\chapsf\sfbshape{17}{1000}
\let\chapbf=\chaprm
\setfont\chapsc\scbshape{10}{\magstep3}
\font\chapi=cmmi12 scaled \magstep2
\font\chapsy=cmsy10 scaled \magstep3

% Section fonts (14.4pt).
\setfont\secrm\rmbshape{12}{\magstep1}
\setfont\secit\itbshape{10}{\magstep2}
\setfont\secsl\slbshape{10}{\magstep2}
\setfont\sectt\ttbshape{12}{\magstep1}
\setfont\secttsl\ttslshape{10}{\magstep2}
\setfont\secsf\sfbshape{12}{\magstep1}
\let\secbf\secrm
\setfont\secsc\scbshape{10}{\magstep2}
\font\seci=cmmi12 scaled \magstep1
\font\secsy=cmsy10 scaled \magstep2

% \setfont\ssecrm\bxshape{10}{\magstep1}    % This size an font looked bad.
% \setfont\ssecit\itshape{10}{\magstep1}    % The letters were too crowded.
% \setfont\ssecsl\slshape{10}{\magstep1}
% \setfont\ssectt\ttshape{10}{\magstep1}
% \setfont\ssecsf\sfshape{10}{\magstep1}

%\setfont\ssecrm\bfshape{10}{1315}      % Note the use of cmb rather than cmbx.
%\setfont\ssecit\itshape{10}{1315}      % Also, the size is a little larger than
%\setfont\ssecsl\slshape{10}{1315}      % being scaled magstep1.
%\setfont\ssectt\ttshape{10}{1315}
%\setfont\ssecsf\sfshape{10}{1315}

%\let\ssecbf=\ssecrm

% Subsection fonts (13.15pt).
\setfont\ssecrm\rmbshape{12}{\magstephalf}
\setfont\ssecit\itbshape{10}{1315}
\setfont\ssecsl\slbshape{10}{1315}
\setfont\ssectt\ttbshape{12}{\magstephalf}
\setfont\ssecttsl\ttslshape{10}{1315}
\setfont\ssecsf\sfbshape{12}{\magstephalf}
\let\ssecbf\ssecrm
\setfont\ssecsc\scbshape{10}{\magstep1}
\font\sseci=cmmi12 scaled \magstephalf
\font\ssecsy=cmsy10 scaled 1315
% The smallcaps and symbol fonts should actually be scaled \magstep1.5,
% but that is not a standard magnification.

% In order for the font changes to affect most math symbols and letters,
% we have to define the \textfont of the standard families.  Since
% texinfo doesn't allow for producing subscripts and superscripts, we
% don't bother to reset \scriptfont and \scriptscriptfont (which would
% also require loading a lot more fonts).
%
\def\resetmathfonts{%
  \textfont0 = \tenrm \textfont1 = \teni \textfont2 = \tensy
  \textfont\itfam = \tenit \textfont\slfam = \tensl \textfont\bffam = \tenbf
  \textfont\ttfam = \tentt \textfont\sffam = \tensf
}


% The font-changing commands redefine the meanings of \tenSTYLE, instead
% of just \STYLE.  We do this so that font changes will continue to work
% in math mode, where it is the current \fam that is relevant in most
% cases, not the current font.  Plain TeX does \def\bf{\fam=\bffam
% \tenbf}, for example.  By redefining \tenbf, we obviate the need to
% redefine \bf itself.
\def\textfonts{%
  \let\tenrm=\textrm \let\tenit=\textit \let\tensl=\textsl
  \let\tenbf=\textbf \let\tentt=\texttt \let\smallcaps=\textsc
  \let\tensf=\textsf \let\teni=\texti \let\tensy=\textsy \let\tenttsl=\textttsl
  \resetmathfonts}
\def\titlefonts{%
  \let\tenrm=\titlerm \let\tenit=\titleit \let\tensl=\titlesl
  \let\tenbf=\titlebf \let\tentt=\titlett \let\smallcaps=\titlesc
  \let\tensf=\titlesf \let\teni=\titlei \let\tensy=\titlesy
  \let\tenttsl=\titlettsl
  \resetmathfonts \setleading{25pt}}
\def\titlefont#1{{\titlefonts\rm #1}}
\def\chapfonts{%
  \let\tenrm=\chaprm \let\tenit=\chapit \let\tensl=\chapsl
  \let\tenbf=\chapbf \let\tentt=\chaptt \let\smallcaps=\chapsc
  \let\tensf=\chapsf \let\teni=\chapi \let\tensy=\chapsy \let\tenttsl=\chapttsl
  \resetmathfonts \setleading{19pt}}
\def\secfonts{%
  \let\tenrm=\secrm \let\tenit=\secit \let\tensl=\secsl
  \let\tenbf=\secbf \let\tentt=\sectt \let\smallcaps=\secsc
  \let\tensf=\secsf \let\teni=\seci \let\tensy=\secsy \let\tenttsl=\secttsl
  \resetmathfonts \setleading{16pt}}
\def\subsecfonts{%
  \let\tenrm=\ssecrm \let\tenit=\ssecit \let\tensl=\ssecsl
  \let\tenbf=\ssecbf \let\tentt=\ssectt \let\smallcaps=\ssecsc
  \let\tensf=\ssecsf \let\teni=\sseci \let\tensy=\ssecsy \let\tenttsl=\ssecttsl
  \resetmathfonts \setleading{15pt}}
\let\subsubsecfonts = \subsecfonts % Maybe make sssec fonts scaled magstephalf?
\def\smallfonts{%
  \let\tenrm=\smallrm \let\tenit=\smallit \let\tensl=\smallsl
  \let\tenbf=\smallbf \let\tentt=\smalltt \let\smallcaps=\smallsc
  \let\tensf=\smallsf \let\teni=\smalli \let\tensy=\smallsy
  \let\tenttsl=\smallttsl
  \resetmathfonts \setleading{11pt}}

% Set up the default fonts, so we can use them for creating boxes.
%
\textfonts

% Define these so they can be easily changed for other fonts.
\def\angleleft{$\langle$}
\def\angleright{$\rangle$}

% Count depth in font-changes, for error checks
\newcount\fontdepth \fontdepth=0

% Fonts for short table of contents.
\setfont\shortcontrm\rmshape{12}{1000}
\setfont\shortcontbf\bxshape{12}{1000}
\setfont\shortcontsl\slshape{12}{1000}

%% Add scribe-like font environments, plus @l for inline lisp (usually sans
%% serif) and @ii for TeX italic

% \smartitalic{ARG} outputs arg in italics, followed by an italic correction
% unless the following character is such as not to need one.
\def\smartitalicx{\ifx\next,\else\ifx\next-\else\ifx\next.\else\/\fi\fi\fi}
\def\smartslanted#1{{\sl #1}\futurelet\next\smartitalicx}
\def\smartitalic#1{{\it #1}\futurelet\next\smartitalicx}

\let\i=\smartitalic
\let\var=\smartslanted
\let\dfn=\smartslanted
\let\emph=\smartitalic
\let\cite=\smartslanted

\def\b#1{{\bf #1}}
\let\strong=\b

% We can't just use \exhyphenpenalty, because that only has effect at
% the end of a paragraph.  Restore normal hyphenation at the end of the
% group within which \nohyphenation is presumably called.
%
\def\nohyphenation{\hyphenchar\font = -1  \aftergroup\restorehyphenation}
\def\restorehyphenation{\hyphenchar\font = `- }

\def\t#1{%
  {\tt \rawbackslash \frenchspacing #1}%
  \null
}
\let\ttfont=\t
\def\samp#1{`\tclose{#1}'\null}
\setfont\keyrm\rmshape{8}{1000}
\font\keysy=cmsy9
\def\key#1{{\keyrm\textfont2=\keysy \leavevmode\hbox{%
  \raise0.4pt\hbox{\angleleft}\kern-.08em\vtop{%
    \vbox{\hrule\kern-0.4pt
     \hbox{\raise0.4pt\hbox{\vphantom{\angleleft}}#1}}%
    \kern-0.4pt\hrule}%
  \kern-.06em\raise0.4pt\hbox{\angleright}}}}
% The old definition, with no lozenge:
%\def\key #1{{\ttsl \nohyphenation \uppercase{#1}}\null}
\def\ctrl #1{{\tt \rawbackslash \hat}#1}

% @file, @option are the same as @samp.
\let\file=\samp
\let\option=\samp

% @code is a modification of @t,
% which makes spaces the same size as normal in the surrounding text.
\def\tclose#1{%
  {%
    % Change normal interword space to be same as for the current font.
    \spaceskip = \fontdimen2\font
    %
    % Switch to typewriter.
    \tt
    %
    % But `\ ' produces the large typewriter interword space.
    \def\ {{\spaceskip = 0pt{} }}%
    %
    % Turn off hyphenation.
    \nohyphenation
    %
    \rawbackslash
    \frenchspacing
    #1%
  }%
  \null
}

% We *must* turn on hyphenation at `-' and `_' in \code.
% Otherwise, it is too hard to avoid overfull hboxes
% in the Emacs manual, the Library manual, etc.

% Unfortunately, TeX uses one parameter (\hyphenchar) to control
% both hyphenation at - and hyphenation within words.
% We must therefore turn them both off (\tclose does that)
% and arrange explicitly to hyphenate at a dash.
%  -- rms.
{
  \catcode`\-=\active
  \catcode`\_=\active
  %
  \global\def\code{\begingroup
    \catcode`\-=\active \let-\codedash
    \catcode`\_=\active \let_\codeunder
    \codex
  }
  %
  % If we end up with any active - characters when handling the index,
  % just treat them as a normal -.
  \global\def\indexbreaks{\catcode`\-=\active \let-\realdash}
}

\def\realdash{-}
\def\codedash{-\discretionary{}{}{}}
\def\codeunder{\ifusingtt{\normalunderscore\discretionary{}{}{}}{\_}}
\def\codex #1{\tclose{#1}\endgroup}

%\let\exp=\tclose  %Was temporary

% @kbd is like @code, except that if the argument is just one @key command,
% then @kbd has no effect.

% @kbdinputstyle -- arg is `distinct' (@kbd uses slanted tty font always),
%   `example' (@kbd uses ttsl only inside of @example and friends),
%   or `code' (@kbd uses normal tty font always).
\def\kbdinputstyle{\parsearg\kbdinputstylexxx}
\def\kbdinputstylexxx#1{%
  \def\arg{#1}%
  \ifx\arg\worddistinct
    \gdef\kbdexamplefont{\ttsl}\gdef\kbdfont{\ttsl}%
  \else\ifx\arg\wordexample
    \gdef\kbdexamplefont{\ttsl}\gdef\kbdfont{\tt}%
  \else\ifx\arg\wordcode
    \gdef\kbdexamplefont{\tt}\gdef\kbdfont{\tt}%
  \fi\fi\fi
}
\def\worddistinct{distinct}
\def\wordexample{example}
\def\wordcode{code}

% Default is kbdinputdistinct.  (Too much of a hassle to call the macro,
% the catcodes are wrong for parsearg to work.)
\gdef\kbdexamplefont{\ttsl}\gdef\kbdfont{\ttsl}

\def\xkey{\key}
\def\kbdfoo#1#2#3\par{\def\one{#1}\def\three{#3}\def\threex{??}%
\ifx\one\xkey\ifx\threex\three \key{#2}%
\else{\tclose{\kbdfont\look}}\fi
\else{\tclose{\kbdfont\look}}\fi}

% For @url, @env, @command quotes seem unnecessary, so use \code.
\let\url=\code
\let\env=\code
\let\command=\code

% @uref (abbreviation for `urlref') takes an optional (comma-separated)
% second argument specifying the text to display and an optional third
% arg as text to display instead of (rather than in addition to) the url
% itself.  First (mandatory) arg is the url.  Perhaps eventually put in
% a hypertex \special here.
%
\def\uref#1{\douref #1,,,\finish}
\def\douref#1,#2,#3,#4\finish{\begingroup
  \unsepspaces
  \pdfurl{#1}%
  \setbox0 = \hbox{\ignorespaces #3}%
  \ifdim\wd0 > 0pt
    \unhbox0 % third arg given, show only that
  \else
    \setbox0 = \hbox{\ignorespaces #2}%
    \ifdim\wd0 > 0pt
      \ifpdf
        \unhbox0             % PDF: 2nd arg given, show only it
      \else
        \unhbox0\ (\code{#1})% DVI: 2nd arg given, show both it and url
      \fi
    \else
      \code{#1}% only url given, so show it
    \fi
  \fi
  \endlink
\endgroup}

% rms does not like angle brackets --karl, 17may97.
% So now @email is just like @uref, unless we are pdf.
% 
%\def\email#1{\angleleft{\tt #1}\angleright}
\ifpdf
  \def\email#1{\doemail#1,,\finish}
  \def\doemail#1,#2,#3\finish{\begingroup
    \unsepspaces
    \pdfurl{mailto:#1}%
    \setbox0 = \hbox{\ignorespaces #2}%
    \ifdim\wd0>0pt\unhbox0\else\code{#1}\fi
    \endlink
  \endgroup}
\else
  \let\email=\uref
\fi

% Check if we are currently using a typewriter font.  Since all the
% Computer Modern typewriter fonts have zero interword stretch (and
% shrink), and it is reasonable to expect all typewriter fonts to have
% this property, we can check that font parameter.
%
\def\ifmonospace{\ifdim\fontdimen3\font=0pt }

% Typeset a dimension, e.g., `in' or `pt'.  The only reason for the
% argument is to make the input look right: @dmn{pt} instead of @dmn{}pt.
%
\def\dmn#1{\thinspace #1}

\def\kbd#1{\def\look{#1}\expandafter\kbdfoo\look??\par}

% @l was never documented to mean ``switch to the Lisp font'',
% and it is not used as such in any manual I can find.  We need it for
% Polish suppressed-l.  --karl, 22sep96.
%\def\l#1{{\li #1}\null}

% Explicit font changes: @r, @sc, undocumented @ii.
\def\r#1{{\rm #1}}              % roman font
\def\sc#1{{\smallcaps#1}}       % smallcaps font
\def\ii#1{{\it #1}}             % italic font

% @acronym downcases the argument and prints in smallcaps.
\def\acronym#1{{\smallcaps \lowercase{#1}}}

% @pounds{} is a sterling sign.
\def\pounds{{\it\$}}


\message{page headings,}

\newskip\titlepagetopglue \titlepagetopglue = 1.5in
\newskip\titlepagebottomglue \titlepagebottomglue = 2pc

% First the title page.  Must do @settitle before @titlepage.
\newif\ifseenauthor
\newif\iffinishedtitlepage

% Do an implicit @contents or @shortcontents after @end titlepage if the
% user says @setcontentsaftertitlepage or @setshortcontentsaftertitlepage.
%
\newif\ifsetcontentsaftertitlepage
 \let\setcontentsaftertitlepage = \setcontentsaftertitlepagetrue
\newif\ifsetshortcontentsaftertitlepage
 \let\setshortcontentsaftertitlepage = \setshortcontentsaftertitlepagetrue

\def\shorttitlepage{\parsearg\shorttitlepagezzz}
\def\shorttitlepagezzz #1{\begingroup\hbox{}\vskip 1.5in \chaprm \centerline{#1}%
        \endgroup\page\hbox{}\page}

\def\titlepage{\begingroup \parindent=0pt \textfonts
   \let\subtitlerm=\tenrm
   \def\subtitlefont{\subtitlerm \normalbaselineskip = 13pt \normalbaselines}%
   %
   \def\authorfont{\authorrm \normalbaselineskip = 16pt \normalbaselines}%
   %
   % Leave some space at the very top of the page.
   \vglue\titlepagetopglue
   %
   % Now you can print the title using @title.
   \def\title{\parsearg\titlezzz}%
   \def\titlezzz##1{\leftline{\titlefonts\rm ##1}
                    % print a rule at the page bottom also.
                    \finishedtitlepagefalse
                    \vskip4pt \hrule height 4pt width \hsize \vskip4pt}%
   % No rule at page bottom unless we print one at the top with @title.
   \finishedtitlepagetrue
   %
   % Now you can put text using @subtitle.
   \def\subtitle{\parsearg\subtitlezzz}%
   \def\subtitlezzz##1{{\subtitlefont \rightline{##1}}}%
   %
   % @author should come last, but may come many times.
   \def\author{\parsearg\authorzzz}%
   \def\authorzzz##1{\ifseenauthor\else\vskip 0pt plus 1filll\seenauthortrue\fi
      {\authorfont \leftline{##1}}}%
   %
   % Most title ``pages'' are actually two pages long, with space
   % at the top of the second.  We don't want the ragged left on the second.
   \let\oldpage = \page
   \def\page{%
      \iffinishedtitlepage\else
         \finishtitlepage
      \fi
      \oldpage
      \let\page = \oldpage
      \hbox{}}%
%   \def\page{\oldpage \hbox{}}
}

\def\Etitlepage{%
   \iffinishedtitlepage\else
      \finishtitlepage
   \fi
   % It is important to do the page break before ending the group,
   % because the headline and footline are only empty inside the group.
   % If we use the new definition of \page, we always get a blank page
   % after the title page, which we certainly don't want.
   \oldpage
   \endgroup
   %
   % If they want short, they certainly want long too.
   \ifsetshortcontentsaftertitlepage
     \shortcontents
     \contents
     \global\let\shortcontents = \relax
     \global\let\contents = \relax
   \fi
   %
   \ifsetcontentsaftertitlepage
     \contents
     \global\let\contents = \relax
     \global\let\shortcontents = \relax
   \fi
   %
   \ifpdf \pdfmakepagedesttrue \fi
   %
   \HEADINGSon
}

\def\finishtitlepage{%
   \vskip4pt \hrule height 2pt width \hsize
   \vskip\titlepagebottomglue
   \finishedtitlepagetrue
}

%%% Set up page headings and footings.

\let\thispage=\folio

\newtoks\evenheadline    % headline on even pages
\newtoks\oddheadline     % headline on odd pages
\newtoks\evenfootline    % footline on even pages
\newtoks\oddfootline     % footline on odd pages

% Now make Tex use those variables
\headline={{\textfonts\rm \ifodd\pageno \the\oddheadline
                            \else \the\evenheadline \fi}}
\footline={{\textfonts\rm \ifodd\pageno \the\oddfootline
                            \else \the\evenfootline \fi}\HEADINGShook}
\let\HEADINGShook=\relax

% Commands to set those variables.
% For example, this is what  @headings on  does
% @evenheading @thistitle|@thispage|@thischapter
% @oddheading @thischapter|@thispage|@thistitle
% @evenfooting @thisfile||
% @oddfooting ||@thisfile

\def\evenheading{\parsearg\evenheadingxxx}
\def\oddheading{\parsearg\oddheadingxxx}
\def\everyheading{\parsearg\everyheadingxxx}

\def\evenfooting{\parsearg\evenfootingxxx}
\def\oddfooting{\parsearg\oddfootingxxx}
\def\everyfooting{\parsearg\everyfootingxxx}

{\catcode`\@=0 %

\gdef\evenheadingxxx #1{\evenheadingyyy #1@|@|@|@|\finish}
\gdef\evenheadingyyy #1@|#2@|#3@|#4\finish{%
\global\evenheadline={\rlap{\centerline{#2}}\line{#1\hfil#3}}}

\gdef\oddheadingxxx #1{\oddheadingyyy #1@|@|@|@|\finish}
\gdef\oddheadingyyy #1@|#2@|#3@|#4\finish{%
\global\oddheadline={\rlap{\centerline{#2}}\line{#1\hfil#3}}}

\gdef\everyheadingxxx#1{\oddheadingxxx{#1}\evenheadingxxx{#1}}%

\gdef\evenfootingxxx #1{\evenfootingyyy #1@|@|@|@|\finish}
\gdef\evenfootingyyy #1@|#2@|#3@|#4\finish{%
\global\evenfootline={\rlap{\centerline{#2}}\line{#1\hfil#3}}}

\gdef\oddfootingxxx #1{\oddfootingyyy #1@|@|@|@|\finish}
\gdef\oddfootingyyy #1@|#2@|#3@|#4\finish{%
  \global\oddfootline = {\rlap{\centerline{#2}}\line{#1\hfil#3}}%
  %
  % Leave some space for the footline.  Hopefully ok to assume
  % @evenfooting will not be used by itself.
  \global\advance\pageheight by -\baselineskip
  \global\advance\vsize by -\baselineskip
}

\gdef\everyfootingxxx#1{\oddfootingxxx{#1}\evenfootingxxx{#1}}
%
}% unbind the catcode of @.

% @headings double      turns headings on for double-sided printing.
% @headings single      turns headings on for single-sided printing.
% @headings off         turns them off.
% @headings on          same as @headings double, retained for compatibility.
% @headings after       turns on double-sided headings after this page.
% @headings doubleafter turns on double-sided headings after this page.
% @headings singleafter turns on single-sided headings after this page.
% By default, they are off at the start of a document,
% and turned `on' after @end titlepage.

\def\headings #1 {\csname HEADINGS#1\endcsname}

\def\HEADINGSoff{
\global\evenheadline={\hfil} \global\evenfootline={\hfil}
\global\oddheadline={\hfil} \global\oddfootline={\hfil}}
\HEADINGSoff
% When we turn headings on, set the page number to 1.
% For double-sided printing, put current file name in lower left corner,
% chapter name on inside top of right hand pages, document
% title on inside top of left hand pages, and page numbers on outside top
% edge of all pages.
\def\HEADINGSdouble{
\global\pageno=1
\global\evenfootline={\hfil}
\global\oddfootline={\hfil}
\global\evenheadline={\line{\folio\hfil\thistitle}}
\global\oddheadline={\line{\thischapter\hfil\folio}}
\global\let\contentsalignmacro = \chapoddpage
}
\let\contentsalignmacro = \chappager

% For single-sided printing, chapter title goes across top left of page,
% page number on top right.
\def\HEADINGSsingle{
\global\pageno=1
\global\evenfootline={\hfil}
\global\oddfootline={\hfil}
\global\evenheadline={\line{\thischapter\hfil\folio}}
\global\oddheadline={\line{\thischapter\hfil\folio}}
\global\let\contentsalignmacro = \chappager
}
\def\HEADINGSon{\HEADINGSdouble}

\def\HEADINGSafter{\let\HEADINGShook=\HEADINGSdoublex}
\let\HEADINGSdoubleafter=\HEADINGSafter
\def\HEADINGSdoublex{%
\global\evenfootline={\hfil}
\global\oddfootline={\hfil}
\global\evenheadline={\line{\folio\hfil\thistitle}}
\global\oddheadline={\line{\thischapter\hfil\folio}}
\global\let\contentsalignmacro = \chapoddpage
}

\def\HEADINGSsingleafter{\let\HEADINGShook=\HEADINGSsinglex}
\def\HEADINGSsinglex{%
\global\evenfootline={\hfil}
\global\oddfootline={\hfil}
\global\evenheadline={\line{\thischapter\hfil\folio}}
\global\oddheadline={\line{\thischapter\hfil\folio}}
\global\let\contentsalignmacro = \chappager
}

% Subroutines used in generating headings
% This produces Day Month Year style of output.
% Only define if not already defined, in case a txi-??.tex file has set
% up a different format (e.g., txi-cs.tex does this).
\ifx\today\undefined
\def\today{%
  \number\day\space
  \ifcase\month
  \or\putwordMJan\or\putwordMFeb\or\putwordMMar\or\putwordMApr
  \or\putwordMMay\or\putwordMJun\or\putwordMJul\or\putwordMAug
  \or\putwordMSep\or\putwordMOct\or\putwordMNov\or\putwordMDec
  \fi
  \space\number\year}
\fi

% @settitle line...  specifies the title of the document, for headings.
% It generates no output of its own.
\def\thistitle{\putwordNoTitle}
\def\settitle{\parsearg\settitlezzz}
\def\settitlezzz #1{\gdef\thistitle{#1}}


\message{tables,}
% Tables -- @table, @ftable, @vtable, @item(x), @kitem(x), @xitem(x).

% default indentation of table text
\newdimen\tableindent \tableindent=.8in
% default indentation of @itemize and @enumerate text
\newdimen\itemindent  \itemindent=.3in
% margin between end of table item and start of table text.
\newdimen\itemmargin  \itemmargin=.1in

% used internally for \itemindent minus \itemmargin
\newdimen\itemmax

% Note @table, @vtable, and @vtable define @item, @itemx, etc., with
% these defs.
% They also define \itemindex
% to index the item name in whatever manner is desired (perhaps none).

\newif\ifitemxneedsnegativevskip

\def\itemxpar{\par\ifitemxneedsnegativevskip\nobreak\vskip-\parskip\nobreak\fi}

\def\internalBitem{\smallbreak \parsearg\itemzzz}
\def\internalBitemx{\itemxpar \parsearg\itemzzz}

\def\internalBxitem "#1"{\def\xitemsubtopix{#1} \smallbreak \parsearg\xitemzzz}
\def\internalBxitemx "#1"{\def\xitemsubtopix{#1} \itemxpar \parsearg\xitemzzz}

\def\internalBkitem{\smallbreak \parsearg\kitemzzz}
\def\internalBkitemx{\itemxpar \parsearg\kitemzzz}

\def\kitemzzz #1{\dosubind {kw}{\code{#1}}{for {\bf \lastfunction}}%
                 \itemzzz {#1}}

\def\xitemzzz #1{\dosubind {kw}{\code{#1}}{for {\bf \xitemsubtopic}}%
                 \itemzzz {#1}}

\def\itemzzz #1{\begingroup %
  \advance\hsize by -\rightskip
  \advance\hsize by -\tableindent
  \setbox0=\hbox{\itemfont{#1}}%
  \itemindex{#1}%
  \nobreak % This prevents a break before @itemx.
  %
  % If the item text does not fit in the space we have, put it on a line
  % by itself, and do not allow a page break either before or after that
  % line.  We do not start a paragraph here because then if the next
  % command is, e.g., @kindex, the whatsit would get put into the
  % horizontal list on a line by itself, resulting in extra blank space.
  \ifdim \wd0>\itemmax
    %
    % Make this a paragraph so we get the \parskip glue and wrapping,
    % but leave it ragged-right.
    \begingroup
      \advance\leftskip by-\tableindent
      \advance\hsize by\tableindent
      \advance\rightskip by0pt plus1fil
      \leavevmode\unhbox0\par
    \endgroup
    %
    % We're going to be starting a paragraph, but we don't want the
    % \parskip glue -- logically it's part of the @item we just started.
    \nobreak \vskip-\parskip
    %
    % Stop a page break at the \parskip glue coming up.  Unfortunately
    % we can't prevent a possible page break at the following
    % \baselineskip glue.
    \nobreak
    \endgroup
    \itemxneedsnegativevskipfalse
  \else
    % The item text fits into the space.  Start a paragraph, so that the
    % following text (if any) will end up on the same line.
    \noindent
    % Do this with kerns and \unhbox so that if there is a footnote in
    % the item text, it can migrate to the main vertical list and
    % eventually be printed.
    \nobreak\kern-\tableindent
    \dimen0 = \itemmax  \advance\dimen0 by \itemmargin \advance\dimen0 by -\wd0
    \unhbox0
    \nobreak\kern\dimen0
    \endgroup
    \itemxneedsnegativevskiptrue
  \fi
}

\def\item{\errmessage{@item while not in a table}}
\def\itemx{\errmessage{@itemx while not in a table}}
\def\kitem{\errmessage{@kitem while not in a table}}
\def\kitemx{\errmessage{@kitemx while not in a table}}
\def\xitem{\errmessage{@xitem while not in a table}}
\def\xitemx{\errmessage{@xitemx while not in a table}}

% Contains a kludge to get @end[description] to work.
\def\description{\tablez{\dontindex}{1}{}{}{}{}}

% @table, @ftable, @vtable.
\def\table{\begingroup\inENV\obeylines\obeyspaces\tablex}
{\obeylines\obeyspaces%
\gdef\tablex #1^^M{%
\tabley\dontindex#1        \endtabley}}

\def\ftable{\begingroup\inENV\obeylines\obeyspaces\ftablex}
{\obeylines\obeyspaces%
\gdef\ftablex #1^^M{%
\tabley\fnitemindex#1        \endtabley
\def\Eftable{\endgraf\afterenvbreak\endgroup}%
\let\Etable=\relax}}

\def\vtable{\begingroup\inENV\obeylines\obeyspaces\vtablex}
{\obeylines\obeyspaces%
\gdef\vtablex #1^^M{%
\tabley\vritemindex#1        \endtabley
\def\Evtable{\endgraf\afterenvbreak\endgroup}%
\let\Etable=\relax}}

\def\dontindex #1{}
\def\fnitemindex #1{\doind {fn}{\code{#1}}}%
\def\vritemindex #1{\doind {vr}{\code{#1}}}%

{\obeyspaces %
\gdef\tabley#1#2 #3 #4 #5 #6 #7\endtabley{\endgroup%
\tablez{#1}{#2}{#3}{#4}{#5}{#6}}}

\def\tablez #1#2#3#4#5#6{%
\aboveenvbreak %
\begingroup %
\def\Edescription{\Etable}% Necessary kludge.
\let\itemindex=#1%
\ifnum 0#3>0 \advance \leftskip by #3\mil \fi %
\ifnum 0#4>0 \tableindent=#4\mil \fi %
\ifnum 0#5>0 \advance \rightskip by #5\mil \fi %
\def\itemfont{#2}%
\itemmax=\tableindent %
\advance \itemmax by -\itemmargin %
\advance \leftskip by \tableindent %
\exdentamount=\tableindent
\parindent = 0pt
\parskip = \smallskipamount
\ifdim \parskip=0pt \parskip=2pt \fi%
\def\Etable{\endgraf\afterenvbreak\endgroup}%
\let\item = \internalBitem %
\let\itemx = \internalBitemx %
\let\kitem = \internalBkitem %
\let\kitemx = \internalBkitemx %
\let\xitem = \internalBxitem %
\let\xitemx = \internalBxitemx %
}

% This is the counter used by @enumerate, which is really @itemize

\newcount \itemno

\def\itemize{\parsearg\itemizezzz}

\def\itemizezzz #1{%
  \begingroup % ended by the @end itemize
  \itemizey {#1}{\Eitemize}
}

\def\itemizey #1#2{%
\aboveenvbreak %
\itemmax=\itemindent %
\advance \itemmax by -\itemmargin %
\advance \leftskip by \itemindent %
\exdentamount=\itemindent
\parindent = 0pt %
\parskip = \smallskipamount %
\ifdim \parskip=0pt \parskip=2pt \fi%
\def#2{\endgraf\afterenvbreak\endgroup}%
\def\itemcontents{#1}%
\let\item=\itemizeitem}

% Set sfcode to normal for the chars that usually have another value.
% These are `.?!:;,'
\def\frenchspacing{\sfcode46=1000 \sfcode63=1000 \sfcode33=1000
  \sfcode58=1000 \sfcode59=1000 \sfcode44=1000 }

% \splitoff TOKENS\endmark defines \first to be the first token in
% TOKENS, and \rest to be the remainder.
%
\def\splitoff#1#2\endmark{\def\first{#1}\def\rest{#2}}%

% Allow an optional argument of an uppercase letter, lowercase letter,
% or number, to specify the first label in the enumerated list.  No
% argument is the same as `1'.
%
\def\enumerate{\parsearg\enumeratezzz}
\def\enumeratezzz #1{\enumeratey #1  \endenumeratey}
\def\enumeratey #1 #2\endenumeratey{%
  \begingroup % ended by the @end enumerate
  %
  % If we were given no argument, pretend we were given `1'.
  \def\thearg{#1}%
  \ifx\thearg\empty \def\thearg{1}\fi
  %
  % Detect if the argument is a single token.  If so, it might be a
  % letter.  Otherwise, the only valid thing it can be is a number.
  % (We will always have one token, because of the test we just made.
  % This is a good thing, since \splitoff doesn't work given nothing at
  % all -- the first parameter is undelimited.)
  \expandafter\splitoff\thearg\endmark
  \ifx\rest\empty
    % Only one token in the argument.  It could still be anything.
    % A ``lowercase letter'' is one whose \lccode is nonzero.
    % An ``uppercase letter'' is one whose \lccode is both nonzero, and
    %   not equal to itself.
    % Otherwise, we assume it's a number.
    %
    % We need the \relax at the end of the \ifnum lines to stop TeX from
    % continuing to look for a <number>.
    %
    \ifnum\lccode\expandafter`\thearg=0\relax
      \numericenumerate % a number (we hope)
    \else
      % It's a letter.
      \ifnum\lccode\expandafter`\thearg=\expandafter`\thearg\relax
        \lowercaseenumerate % lowercase letter
      \else
        \uppercaseenumerate % uppercase letter
      \fi
    \fi
  \else
    % Multiple tokens in the argument.  We hope it's a number.
    \numericenumerate
  \fi
}

% An @enumerate whose labels are integers.  The starting integer is
% given in \thearg.
%
\def\numericenumerate{%
  \itemno = \thearg
  \startenumeration{\the\itemno}%
}

% The starting (lowercase) letter is in \thearg.
\def\lowercaseenumerate{%
  \itemno = \expandafter`\thearg
  \startenumeration{%
    % Be sure we're not beyond the end of the alphabet.
    \ifnum\itemno=0
      \errmessage{No more lowercase letters in @enumerate; get a bigger
                  alphabet}%
    \fi
    \char\lccode\itemno
  }%
}

% The starting (uppercase) letter is in \thearg.
\def\uppercaseenumerate{%
  \itemno = \expandafter`\thearg
  \startenumeration{%
    % Be sure we're not beyond the end of the alphabet.
    \ifnum\itemno=0
      \errmessage{No more uppercase letters in @enumerate; get a bigger
                  alphabet}
    \fi
    \char\uccode\itemno
  }%
}

% Call itemizey, adding a period to the first argument and supplying the
% common last two arguments.  Also subtract one from the initial value in
% \itemno, since @item increments \itemno.
%
\def\startenumeration#1{%
  \advance\itemno by -1
  \itemizey{#1.}\Eenumerate\flushcr
}

% @alphaenumerate and @capsenumerate are abbreviations for giving an arg
% to @enumerate.
%
\def\alphaenumerate{\enumerate{a}}
\def\capsenumerate{\enumerate{A}}
\def\Ealphaenumerate{\Eenumerate}
\def\Ecapsenumerate{\Eenumerate}

% Definition of @item while inside @itemize.

\def\itemizeitem{%
\advance\itemno by 1
{\let\par=\endgraf \smallbreak}%
\ifhmode \errmessage{In hmode at itemizeitem}\fi
{\parskip=0in \hskip 0pt
\hbox to 0pt{\hss \itemcontents\hskip \itemmargin}%
\vadjust{\penalty 1200}}%
\flushcr}

% @multitable macros
% Amy Hendrickson, 8/18/94, 3/6/96
%
% @multitable ... @end multitable will make as many columns as desired.
% Contents of each column will wrap at width given in preamble.  Width
% can be specified either with sample text given in a template line,
% or in percent of \hsize, the current width of text on page.

% Table can continue over pages but will only break between lines.

% To make preamble:
%
% Either define widths of columns in terms of percent of \hsize:
%   @multitable @columnfractions .25 .3 .45
%   @item ...
%
%   Numbers following @columnfractions are the percent of the total
%   current hsize to be used for each column. You may use as many
%   columns as desired.


% Or use a template:
%   @multitable {Column 1 template} {Column 2 template} {Column 3 template}
%   @item ...
%   using the widest term desired in each column.
%
% For those who want to use more than one line's worth of words in
% the preamble, break the line within one argument and it
% will parse correctly, i.e.,
%
%     @multitable {Column 1 template} {Column 2 template} {Column 3
%      template}
% Not:
%     @multitable {Column 1 template} {Column 2 template}
%      {Column 3 template}

% Each new table line starts with @item, each subsequent new column
% starts with @tab. Empty columns may be produced by supplying @tab's
% with nothing between them for as many times as empty columns are needed,
% ie, @tab@tab@tab will produce two empty columns.

% @item, @tab, @multitable or @end multitable do not need to be on their
% own lines, but it will not hurt if they are.

% Sample multitable:

%   @multitable {Column 1 template} {Column 2 template} {Column 3 template}
%   @item first col stuff @tab second col stuff @tab third col
%   @item
%   first col stuff
%   @tab
%   second col stuff
%   @tab
%   third col
%   @item first col stuff @tab second col stuff
%   @tab Many paragraphs of text may be used in any column.
%
%         They will wrap at the width determined by the template.
%   @item@tab@tab This will be in third column.
%   @end multitable

% Default dimensions may be reset by user.
% @multitableparskip is vertical space between paragraphs in table.
% @multitableparindent is paragraph indent in table.
% @multitablecolmargin is horizontal space to be left between columns.
% @multitablelinespace is space to leave between table items, baseline
%                                                            to baseline.
%   0pt means it depends on current normal line spacing.
%
\newskip\multitableparskip
\newskip\multitableparindent
\newdimen\multitablecolspace
\newskip\multitablelinespace
\multitableparskip=0pt
\multitableparindent=6pt
\multitablecolspace=12pt
\multitablelinespace=0pt

% Macros used to set up halign preamble:
%
\let\endsetuptable\relax
\def\xendsetuptable{\endsetuptable}
\let\columnfractions\relax
\def\xcolumnfractions{\columnfractions}
\newif\ifsetpercent

% #1 is the part of the @columnfraction before the decimal point, which
% is presumably either 0 or the empty string (but we don't check, we
% just throw it away).  #2 is the decimal part, which we use as the
% percent of \hsize for this column.
\def\pickupwholefraction#1.#2 {%
  \global\advance\colcount by 1
  \expandafter\xdef\csname col\the\colcount\endcsname{.#2\hsize}%
  \setuptable
}

\newcount\colcount
\def\setuptable#1{%
  \def\firstarg{#1}%
  \ifx\firstarg\xendsetuptable
    \let\go = \relax
  \else
    \ifx\firstarg\xcolumnfractions
      \global\setpercenttrue
    \else
      \ifsetpercent
         \let\go\pickupwholefraction
      \else
         \global\advance\colcount by 1
         \setbox0=\hbox{#1\unskip }% Add a normal word space as a separator;
                            % typically that is always in the input, anyway.
         \expandafter\xdef\csname col\the\colcount\endcsname{\the\wd0}%
      \fi
    \fi
    \ifx\go\pickupwholefraction
      % Put the argument back for the \pickupwholefraction call, so
      % we'll always have a period there to be parsed.
      \def\go{\pickupwholefraction#1}%
    \else
      \let\go = \setuptable
    \fi%
  \fi
  \go
}

% This used to have \hskip1sp.  But then the space in a template line is
% not enough.  That is bad.  So let's go back to just & until we
% encounter the problem it was intended to solve again.
% --karl, nathan@acm.org, 20apr99.
\def\tab{&}

% @multitable ... @end multitable definitions:
%
\def\multitable{\parsearg\dotable}
\def\dotable#1{\bgroup
  \vskip\parskip
  \let\item\crcr
  \tolerance=9500
  \hbadness=9500
  \setmultitablespacing
  \parskip=\multitableparskip
  \parindent=\multitableparindent
  \overfullrule=0pt
  \global\colcount=0
  \def\Emultitable{\global\setpercentfalse\cr\egroup\egroup}%
  %
  % To parse everything between @multitable and @item:
  \setuptable#1 \endsetuptable
  %
  % \everycr will reset column counter, \colcount, at the end of
  % each line. Every column entry will cause \colcount to advance by one.
  % The table preamble
  % looks at the current \colcount to find the correct column width.
  \everycr{\noalign{%
  %
  % \filbreak%% keeps underfull box messages off when table breaks over pages.
  % Maybe so, but it also creates really weird page breaks when the table
  % breaks over pages. Wouldn't \vfil be better?  Wait until the problem
  % manifests itself, so it can be fixed for real --karl.
    \global\colcount=0\relax}}%
  %
  % This preamble sets up a generic column definition, which will
  % be used as many times as user calls for columns.
  % \vtop will set a single line and will also let text wrap and
  % continue for many paragraphs if desired.
  \halign\bgroup&\global\advance\colcount by 1\relax
    \multistrut\vtop{\hsize=\expandafter\csname col\the\colcount\endcsname
  %
  % In order to keep entries from bumping into each other
  % we will add a \leftskip of \multitablecolspace to all columns after
  % the first one.
  %
  % If a template has been used, we will add \multitablecolspace
  % to the width of each template entry.
  %
  % If the user has set preamble in terms of percent of \hsize we will
  % use that dimension as the width of the column, and the \leftskip
  % will keep entries from bumping into each other.  Table will start at
  % left margin and final column will justify at right margin.
  %
  % Make sure we don't inherit \rightskip from the outer environment.
  \rightskip=0pt
  \ifnum\colcount=1
    % The first column will be indented with the surrounding text.
    \advance\hsize by\leftskip
  \else
    \ifsetpercent \else
      % If user has not set preamble in terms of percent of \hsize
      % we will advance \hsize by \multitablecolspace.
      \advance\hsize by \multitablecolspace
    \fi
   % In either case we will make \leftskip=\multitablecolspace:
  \leftskip=\multitablecolspace
  \fi
  % Ignoring space at the beginning and end avoids an occasional spurious
  % blank line, when TeX decides to break the line at the space before the
  % box from the multistrut, so the strut ends up on a line by itself.
  % For example:
  % @multitable @columnfractions .11 .89
  % @item @code{#}
  % @tab Legal holiday which is valid in major parts of the whole country.
  % Is automatically provided with highlighting sequences respectively marking
  % characters.
  \noindent\ignorespaces##\unskip\multistrut}\cr
}

\def\setmultitablespacing{% test to see if user has set \multitablelinespace.
% If so, do nothing. If not, give it an appropriate dimension based on
% current baselineskip.
\ifdim\multitablelinespace=0pt
\setbox0=\vbox{X}\global\multitablelinespace=\the\baselineskip
\global\advance\multitablelinespace by-\ht0
%% strut to put in table in case some entry doesn't have descenders,
%% to keep lines equally spaced
\let\multistrut = \strut
\else
%% FIXME: what is \box0 supposed to be?
\gdef\multistrut{\vrule height\multitablelinespace depth\dp0
width0pt\relax} \fi
%% Test to see if parskip is larger than space between lines of
%% table. If not, do nothing.
%%        If so, set to same dimension as multitablelinespace.
\ifdim\multitableparskip>\multitablelinespace
\global\multitableparskip=\multitablelinespace
\global\advance\multitableparskip-7pt %% to keep parskip somewhat smaller
                                      %% than skip between lines in the table.
\fi%
\ifdim\multitableparskip=0pt
\global\multitableparskip=\multitablelinespace
\global\advance\multitableparskip-7pt %% to keep parskip somewhat smaller
                                      %% than skip between lines in the table.
\fi}


\message{conditionals,}
% Prevent errors for section commands.
% Used in @ignore and in failing conditionals.
\def\ignoresections{%
  \let\chapter=\relax
  \let\unnumbered=\relax
  \let\top=\relax
  \let\unnumberedsec=\relax
  \let\unnumberedsection=\relax
  \let\unnumberedsubsec=\relax
  \let\unnumberedsubsection=\relax
  \let\unnumberedsubsubsec=\relax
  \let\unnumberedsubsubsection=\relax
  \let\section=\relax
  \let\subsec=\relax
  \let\subsubsec=\relax
  \let\subsection=\relax
  \let\subsubsection=\relax
  \let\appendix=\relax
  \let\appendixsec=\relax
  \let\appendixsection=\relax
  \let\appendixsubsec=\relax
  \let\appendixsubsection=\relax
  \let\appendixsubsubsec=\relax
  \let\appendixsubsubsection=\relax
  \let\contents=\relax
  \let\smallbook=\relax
  \let\titlepage=\relax
}

% Used in nested conditionals, where we have to parse the Texinfo source
% and so want to turn off most commands, in case they are used
% incorrectly.
%
\def\ignoremorecommands{%
  \let\defcodeindex = \relax
  \let\defcv = \relax
  \let\deffn = \relax
  \let\deffnx = \relax
  \let\defindex = \relax
  \let\defivar = \relax
  \let\defmac = \relax
  \let\defmethod = \relax
  \let\defop = \relax
  \let\defopt = \relax
  \let\defspec = \relax
  \let\deftp = \relax
  \let\deftypefn = \relax
  \let\deftypefun = \relax
  \let\deftypeivar = \relax
  \let\deftypeop = \relax
  \let\deftypevar = \relax
  \let\deftypevr = \relax
  \let\defun = \relax
  \let\defvar = \relax
  \let\defvr = \relax
  \let\ref = \relax
  \let\xref = \relax
  \let\printindex = \relax
  \let\pxref = \relax
  \let\settitle = \relax
  \let\setchapternewpage = \relax
  \let\setchapterstyle = \relax
  \let\everyheading = \relax
  \let\evenheading = \relax
  \let\oddheading = \relax
  \let\everyfooting = \relax
  \let\evenfooting = \relax
  \let\oddfooting = \relax
  \let\headings = \relax
  \let\include = \relax
  \let\lowersections = \relax
  \let\down = \relax
  \let\raisesections = \relax
  \let\up = \relax
  \let\set = \relax
  \let\clear = \relax
  \let\item = \relax
}

% Ignore @ignore ... @end ignore.
%
\def\ignore{\doignore{ignore}}

% Ignore @ifinfo, @ifhtml, @ifnottex, @html, @menu, and @direntry text.
%
\def\ifinfo{\doignore{ifinfo}}
\def\ifhtml{\doignore{ifhtml}}
\def\ifnottex{\doignore{ifnottex}}
\def\html{\doignore{html}}
\def\menu{\doignore{menu}}
\def\direntry{\doignore{direntry}}

% @dircategory CATEGORY  -- specify a category of the dir file
% which this file should belong to.  Ignore this in TeX.
\let\dircategory = \comment

% Ignore text until a line `@end #1'.
%
\def\doignore#1{\begingroup
  % Don't complain about control sequences we have declared \outer.
  \ignoresections
  %
  % Define a command to swallow text until we reach `@end #1'.
  % This @ is a catcode 12 token (that is the normal catcode of @ in
  % this texinfo.tex file).  We change the catcode of @ below to match.
  \long\def\doignoretext##1@end #1{\enddoignore}%
  %
  % Make sure that spaces turn into tokens that match what \doignoretext wants.
  \catcode32 = 10
  %
  % Ignore braces, too, so mismatched braces don't cause trouble.
  \catcode`\{ = 9
  \catcode`\} = 9
  %
  % We must not have @c interpreted as a control sequence.
  \catcode`\@ = 12
  %
  % Make the letter c a comment character so that the rest of the line
  % will be ignored. This way, the document can have (for example)
  %   @c @end ifinfo
  % and the @end ifinfo will be properly ignored.
  % (We've just changed @ to catcode 12.)
  \catcode`\c = 14
  %
  % And now expand that command.
  \doignoretext
}

% What we do to finish off ignored text.
%
\def\enddoignore{\endgroup\ignorespaces}%

\newif\ifwarnedobs\warnedobsfalse
\def\obstexwarn{%
  \ifwarnedobs\relax\else
  % We need to warn folks that they may have trouble with TeX 3.0.
  % This uses \immediate\write16 rather than \message to get newlines.
    \immediate\write16{}
    \immediate\write16{WARNING: for users of Unix TeX 3.0!}
    \immediate\write16{This manual trips a bug in TeX version 3.0 (tex hangs).}
    \immediate\write16{If you are running another version of TeX, relax.}
    \immediate\write16{If you are running Unix TeX 3.0, kill this TeX process.}
    \immediate\write16{  Then upgrade your TeX installation if you can.}
    \immediate\write16{  (See ftp://ftp.gnu.org/pub/gnu/TeX.README.)}
    \immediate\write16{If you are stuck with version 3.0, run the}
    \immediate\write16{  script ``tex3patch'' from the Texinfo distribution}
    \immediate\write16{  to use a workaround.}
    \immediate\write16{}
    \global\warnedobstrue
    \fi
}

% **In TeX 3.0, setting text in \nullfont hangs tex.  For a
% workaround (which requires the file ``dummy.tfm'' to be installed),
% uncomment the following line:
%%%%%\font\nullfont=dummy\let\obstexwarn=\relax

% Ignore text, except that we keep track of conditional commands for
% purposes of nesting, up to an `@end #1' command.
%
\def\nestedignore#1{%
  \obstexwarn
  % We must actually expand the ignored text to look for the @end
  % command, so that nested ignore constructs work.  Thus, we put the
  % text into a \vbox and then do nothing with the result.  To minimize
  % the change of memory overflow, we follow the approach outlined on
  % page 401 of the TeXbook: make the current font be a dummy font.
  %
  \setbox0 = \vbox\bgroup
    % Don't complain about control sequences we have declared \outer.
    \ignoresections
    %
    % Define `@end #1' to end the box, which will in turn undefine the
    % @end command again.
    \expandafter\def\csname E#1\endcsname{\egroup\ignorespaces}%
    %
    % We are going to be parsing Texinfo commands.  Most cause no
    % trouble when they are used incorrectly, but some commands do
    % complicated argument parsing or otherwise get confused, so we
    % undefine them.
    %
    % We can't do anything about stray @-signs, unfortunately;
    % they'll produce `undefined control sequence' errors.
    \ignoremorecommands
    %
    % Set the current font to be \nullfont, a TeX primitive, and define
    % all the font commands to also use \nullfont.  We don't use
    % dummy.tfm, as suggested in the TeXbook, because not all sites
    % might have that installed.  Therefore, math mode will still
    % produce output, but that should be an extremely small amount of
    % stuff compared to the main input.
    %
    \nullfont
    \let\tenrm=\nullfont \let\tenit=\nullfont \let\tensl=\nullfont
    \let\tenbf=\nullfont \let\tentt=\nullfont \let\smallcaps=\nullfont
    \let\tensf=\nullfont
    % Similarly for index fonts (mostly for their use in smallexample).
    \let\smallrm=\nullfont \let\smallit=\nullfont \let\smallsl=\nullfont
    \let\smallbf=\nullfont \let\smalltt=\nullfont \let\smallsc=\nullfont
    \let\smallsf=\nullfont
    %
    % Don't complain when characters are missing from the fonts.
    \tracinglostchars = 0
    %
    % Don't bother to do space factor calculations.
    \frenchspacing
    %
    % Don't report underfull hboxes.
    \hbadness = 10000
    %
    % Do minimal line-breaking.
    \pretolerance = 10000
    %
    % Do not execute instructions in @tex
    \def\tex{\doignore{tex}}%
    % Do not execute macro definitions.
    % `c' is a comment character, so the word `macro' will get cut off.
    \def\macro{\doignore{ma}}%
}

% @set VAR sets the variable VAR to an empty value.
% @set VAR REST-OF-LINE sets VAR to the value REST-OF-LINE.
%
% Since we want to separate VAR from REST-OF-LINE (which might be
% empty), we can't just use \parsearg; we have to insert a space of our
% own to delimit the rest of the line, and then take it out again if we
% didn't need it.  Make sure the catcode of space is correct to avoid
% losing inside @example, for instance.
%
\def\set{\begingroup\catcode` =10
  \catcode`\-=12 \catcode`\_=12 % Allow - and _ in VAR.
  \parsearg\setxxx}
\def\setxxx#1{\setyyy#1 \endsetyyy}
\def\setyyy#1 #2\endsetyyy{%
  \def\temp{#2}%
  \ifx\temp\empty \global\expandafter\let\csname SET#1\endcsname = \empty
  \else \setzzz{#1}#2\endsetzzz % Remove the trailing space \setxxx inserted.
  \fi
  \endgroup
}
% Can't use \xdef to pre-expand #2 and save some time, since \temp or
% \next or other control sequences that we've defined might get us into
% an infinite loop. Consider `@set foo @cite{bar}'.
\def\setzzz#1#2 \endsetzzz{\expandafter\gdef\csname SET#1\endcsname{#2}}

% @clear VAR clears (i.e., unsets) the variable VAR.
%
\def\clear{\parsearg\clearxxx}
\def\clearxxx#1{\global\expandafter\let\csname SET#1\endcsname=\relax}

% @value{foo} gets the text saved in variable foo.
{
  \catcode`\_ = \active
  %
  % We might end up with active _ or - characters in the argument if
  % we're called from @code, as @code{@value{foo-bar_}}.  So \let any
  % such active characters to their normal equivalents.
  \gdef\value{\begingroup
    \catcode`\-=12 \catcode`\_=12
    \indexbreaks \let_\normalunderscore
    \valuexxx}
}
\def\valuexxx#1{\expandablevalue{#1}\endgroup}

% We have this subroutine so that we can handle at least some @value's
% properly in indexes (we \let\value to this in \indexdummies).  Ones
% whose names contain - or _ still won't work, but we can't do anything
% about that.  The command has to be fully expandable, since the result
% winds up in the index file.  This means that if the variable's value
% contains other Texinfo commands, it's almost certain it will fail
% (although perhaps we could fix that with sufficient work to do a
% one-level expansion on the result, instead of complete).
%
\def\expandablevalue#1{%
  \expandafter\ifx\csname SET#1\endcsname\relax
    {[No value for ``#1'']}%
  \else
    \csname SET#1\endcsname
  \fi
}

% @ifset VAR ... @end ifset reads the `...' iff VAR has been defined
% with @set.
%
\def\ifset{\parsearg\ifsetxxx}
\def\ifsetxxx #1{%
  \expandafter\ifx\csname SET#1\endcsname\relax
    \expandafter\ifsetfail
  \else
    \expandafter\ifsetsucceed
  \fi
}
\def\ifsetsucceed{\conditionalsucceed{ifset}}
\def\ifsetfail{\nestedignore{ifset}}
\defineunmatchedend{ifset}

% @ifclear VAR ... @end ifclear reads the `...' iff VAR has never been
% defined with @set, or has been undefined with @clear.
%
\def\ifclear{\parsearg\ifclearxxx}
\def\ifclearxxx #1{%
  \expandafter\ifx\csname SET#1\endcsname\relax
    \expandafter\ifclearsucceed
  \else
    \expandafter\ifclearfail
  \fi
}
\def\ifclearsucceed{\conditionalsucceed{ifclear}}
\def\ifclearfail{\nestedignore{ifclear}}
\defineunmatchedend{ifclear}

% @iftex, @ifnothtml, @ifnotinfo always succeed; we read the text
% following, through the first @end iftex (etc.).  Make `@end iftex'
% (etc.) valid only after an @iftex.
%
\def\iftex{\conditionalsucceed{iftex}}
\def\ifnothtml{\conditionalsucceed{ifnothtml}}
\def\ifnotinfo{\conditionalsucceed{ifnotinfo}}
\defineunmatchedend{iftex}
\defineunmatchedend{ifnothtml}
\defineunmatchedend{ifnotinfo}

% We can't just want to start a group at @iftex (for example) and end it
% at @end iftex, since then @set commands inside the conditional have no
% effect (they'd get reverted at the end of the group).  So we must
% define \Eiftex to redefine itself to be its previous value.  (We can't
% just define it to fail again with an ``unmatched end'' error, since
% the @ifset might be nested.)
%
\def\conditionalsucceed#1{%
  \edef\temp{%
    % Remember the current value of \E#1.
    \let\nece{prevE#1} = \nece{E#1}%
    %
    % At the `@end #1', redefine \E#1 to be its previous value.
    \def\nece{E#1}{\let\nece{E#1} = \nece{prevE#1}}%
  }%
  \temp
}

% We need to expand lots of \csname's, but we don't want to expand the
% control sequences after we've constructed them.
%
\def\nece#1{\expandafter\noexpand\csname#1\endcsname}

% @defininfoenclose.
\let\definfoenclose=\comment


\message{indexing,}
% Index generation facilities

% Define \newwrite to be identical to plain tex's \newwrite
% except not \outer, so it can be used within \newindex.
{\catcode`\@=11
\gdef\newwrite{\alloc@7\write\chardef\sixt@@n}}

% \newindex {foo} defines an index named foo.
% It automatically defines \fooindex such that
% \fooindex ...rest of line... puts an entry in the index foo.
% It also defines \fooindfile to be the number of the output channel for
% the file that accumulates this index.  The file's extension is foo.
% The name of an index should be no more than 2 characters long
% for the sake of vms.
%
\def\newindex#1{%
  \iflinks
    \expandafter\newwrite \csname#1indfile\endcsname
    \openout \csname#1indfile\endcsname \jobname.#1 % Open the file
  \fi
  \expandafter\xdef\csname#1index\endcsname{%     % Define @#1index
    \noexpand\doindex{#1}}
}

% @defindex foo  ==  \newindex{foo}
%
\def\defindex{\parsearg\newindex}

% Define @defcodeindex, like @defindex except put all entries in @code.
%
\def\defcodeindex{\parsearg\newcodeindex}
%
\def\newcodeindex#1{%
  \iflinks
    \expandafter\newwrite \csname#1indfile\endcsname
    \openout \csname#1indfile\endcsname \jobname.#1
  \fi
  \expandafter\xdef\csname#1index\endcsname{%
    \noexpand\docodeindex{#1}}%
}


% @synindex foo bar    makes index foo feed into index bar.
% Do this instead of @defindex foo if you don't want it as a separate index.
% 
% @syncodeindex foo bar   similar, but put all entries made for in