% 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{2017-05-14.14}

%

% Copyright 1985, 1986, 1988, 1990, 1991, 1992, 1993, 1994, 1995,

% 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,

% 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017

% 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 3 of the

% License, 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 program.  If not, see <http://www.gnu.org/licenses/>.

%

% As a special exception, when this file is read by TeX when processing

% a Texinfo source document, you may use the result without

% restriction. This Exception is an additional permission under section 7

% of the GNU General Public License, version 3 ("GPLv3").

%

% Please try the latest version of texinfo.tex before submitting bug

% reports; you can get the latest version from:

%   http://ftp.gnu.org/gnu/texinfo/ (the Texinfo release area), or

%   http://ftpmirror.gnu.org/texinfo/ (same, via a mirror), or

%   http://www.gnu.org/software/texinfo/ (the Texinfo home page)

% The texinfo.tex in any given distribution could well be out

% of date, so if that's what you're using, please check.

%

% 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; this makes foo.ps.

% The extra TeX runs 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, to some

% extent.  You can get the existing language-specific files from the

% full Texinfo distribution.

%

% The GNU Texinfo home page is http://www.gnu.org/software/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}

% LaTeX's \typeout.  This ensures that the messages it is used for

% are identical in format to the corresponding ones from latex/pdflatex.

\def\typeout{\immediate\write17}%

\chardef\other=12

% We never want plain's \outer definition of \+ in Texinfo.

% For @tex, we can use \tabalign.

\let\+ = \relax

% Save some plain tex macros 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\ptexfootnote=\footnote

\let\ptexgtr=>

\let\ptexhat=^

\let\ptexi=\i

\let\ptexindent=\indent

\let\ptexinsert=\insert

\let\ptexlbrace=\{

\let\ptexless=<

\let\ptexnewwrite\newwrite

\let\ptexnoindent=\noindent

\let\ptexplus=+

\let\ptexraggedright=\raggedright

\let\ptexrbrace=\}

\let\ptexslash=\/

\let\ptexsp=\sp

\let\ptexstar=\*

\let\ptexsup=\sup

\let\ptext=\t

\let\ptextop=\top

{\catcode`\'=\active \global\let\ptexquoteright'}% active in plain's math mode

% If this character appears in an error message or help string, it

% starts a new line in the output.

\newlinechar = `^^J

% Use TeX 3.0's \inputlineno to get the line number, for better error

% messages, but if we're using an old version of TeX, don't do anything.

%

\ifx\inputlineno\thisisundefined

  \let\linenumber = \empty % Pre-3.0.

\else

  \def\linenumber{l.\the\inputlineno:\space}

\fi

% 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\putworderror\undefined     \gdef\putworderror{error}\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\putwordDeffunc\undefined   \gdef\putwordDeffunc{Function}\fi

% Give the space character the catcode for a space.

\def\spaceisspace{\catcode`\ =10\relax}

% Likewise for ^^M, the end of line character.

\def\endlineisspace{\catcode13=10\relax}

\chardef\dashChar  = `\-

\chardef\slashChar = `\/

\chardef\underChar = `\_

% Ignore a token.

%

\def\gobble#1{}

% The following is used inside several \edef's.

\def\makecsname#1{\expandafter\noexpand\csname#1\endcsname}

% Hyphenation fixes.

\hyphenation{

  Flor-i-da Ghost-script Ghost-view Mac-OS Post-Script

  ap-pen-dix bit-map bit-maps

  data-base data-bases eshell fall-ing half-way long-est man-u-script

  man-u-scripts mini-buf-fer mini-buf-fers over-view par-a-digm

  par-a-digms rath-er rec-tan-gu-lar ro-bot-ics se-vere-ly set-up spa-ces

  spell-ing spell-ings

  stand-alone strong-est time-stamp time-stamps which-ever white-space

  wide-spread wrap-around

}

% 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.  We also make

% some effort to order the tracing commands to reduce output in the log

% file; cf. trace.sty in LaTeX.

%

\def\gloggingall{\begingroup \globaldefs = 1 \loggingall \endgroup}%

\def\loggingall{%

  \tracingstats2

  \tracingpages1

  \tracinglostchars2  % 2 gives us more in etex

  \tracingparagraphs1

  \tracingoutput1

  \tracingmacros2

  \tracingrestores1

  \showboxbreadth\maxdimen \showboxdepth\maxdimen

  \ifx\eTeXversion\thisisundefined\else % etex gives us more logging

    \tracingscantokens1

    \tracingifs1

    \tracinggroups1

    \tracingnesting2

    \tracingassigns1

  \fi

  \tracingcommands3  % 3 gives us more in etex

  \errorcontextlines16

}%

% @errormsg{MSG}.  Do the index-like expansions on MSG, but if things

% aren't perfect, it's not the end of the world, being an error message,

% after all.

% 

\def\errormsg{\begingroup \indexnofonts \doerrormsg}

\def\doerrormsg#1{\errmessage{#1}}

% add check for \lastpenalty to plain's definitions.  If the last thing

% we did was a \nobreak, we don't want to insert more space.

%

\def\smallbreak{\ifnum\lastpenalty<10000\par\ifdim\lastskip<\smallskipamount

  \removelastskip\penalty-50\smallskip\fi\fi}

\def\medbreak{\ifnum\lastpenalty<10000\par\ifdim\lastskip<\medskipamount

  \removelastskip\penalty-100\medskip\fi\fi}

\def\bigbreak{\ifnum\lastpenalty<10000\par\ifdim\lastskip<\bigskipamount

  \removelastskip\penalty-200\bigskip\fi\fi}

%? Output routine

%

% For a final copy, take out the rectangles

% that mark overfull boxes (in case you have decided

% that the text looks ok even though it passes the margin).

%

\def\finalout{\overfullrule=0pt }

% 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

% Output a mark which sets \thischapter, \thissection and \thiscolor.

% We dump everything together because we only have one kind of mark.

% This works because we only use \botmark / \topmark, not \firstmark.

%

% A mark contains a subexpression of the \ifcase ... \fi construct.

% \get*marks macros below extract the needed part using \ifcase.

%

% Another complication is to let the user choose whether \thischapter

% (\thissection) refers to the chapter (section) in effect at the top

% of a page, or that at the bottom of a page.

% \domark is called twice inside \chapmacro, to add one

% mark before the section break, and one after.

%   In the second call \prevchapterdefs is the same as \lastchapterdefs,

% and \prevsectiondefs is the same as \lastsectiondefs.

%   Then if the page is not broken at the mark, some of the previous

% section appears on the page, and we can get the name of this section

% from \firstmark for @everyheadingmarks top.

%   @everyheadingmarks bottom uses \botmark.

%

% See page 260 of The TeXbook.

\def\domark{%

  \toks0=\expandafter{\lastchapterdefs}%

  \toks2=\expandafter{\lastsectiondefs}%

  \toks4=\expandafter{\prevchapterdefs}%

  \toks6=\expandafter{\prevsectiondefs}%

  \toks8=\expandafter{\lastcolordefs}%

  \mark{%

                   \the\toks0 \the\toks2  % 0: marks for @everyheadingmarks top

      \noexpand\or \the\toks4 \the\toks6  % 1: for @everyheadingmarks bottom

    \noexpand\else \the\toks8             % 2: color marks

  }%

}

% \gettopheadingmarks, \getbottomheadingmarks,

% \getcolormarks - extract needed part of mark.

%

% \topmark doesn't work for the very first chapter (after the title

% page or the contents), so we use \firstmark there -- this gets us

% the mark with the chapter defs, unless the user sneaks in, e.g.,

% @setcolor (or @url, or @link, etc.) between @contents and the very

% first @chapter.

\def\gettopheadingmarks{%

  \ifcase0\topmark\fi

  \ifx\thischapter\empty \ifcase0\firstmark\fi \fi

}

\def\getbottomheadingmarks{\ifcase1\botmark\fi}

\def\getcolormarks{\ifcase2\topmark\fi}

% Avoid "undefined control sequence" errors.

\def\lastchapterdefs{}

\def\lastsectiondefs{}

\def\lastsection{}

\def\prevchapterdefs{}

\def\prevsectiondefs{}

\def\lastcolordefs{}

% Margin to add to right of even pages, to left of odd pages.

\newdimen\bindingoffset

\newdimen\normaloffset

\newdimen\txipagewidth \newdimen\txipageheight

% Main output routine.

%

\chardef\PAGE = 255

\output = {\onepageout{\pagecontents\PAGE}}

\newbox\headlinebox

\newbox\footlinebox

% \onepageout takes a vbox as an argument.

% \shipout a vbox for a single page, adding an optional header, footer,

% cropmarks, and footnote.  This also causes index entries for this page

% to be written to the auxiliary files.

%

\def\onepageout#1{%

  \ifcropmarks \hoffset=0pt \else \hoffset=\normaloffset \fi

  %

  \ifodd\pageno  \advance\hoffset by \bindingoffset

  \else \advance\hoffset by -\bindingoffset\fi

  %

  % Common context changes for both heading and footing.

  % Do this outside of the \shipout so @code etc. will be expanded in

  % the headline as they should be, not taken literally (outputting ''code).

  \def\commmonheadfootline{\let\hsize=\txipagewidth \texinfochars}

  %

  % Retrieve the information for the headings from the marks in the page,

  % and call Plain TeX's \makeheadline and \makefootline, which use the

  % values in \headline and \footline.

  %

  % This is used to check if we are on the first page of a chapter.

  \ifcase1\topmark\fi

  \let\prevchaptername\thischaptername

  \ifcase0\firstmark\fi

  \let\curchaptername\thischaptername

  %

  \ifodd\pageno \getoddheadingmarks \else \getevenheadingmarks \fi

  \ifodd\pageno \getoddfootingmarks \else \getevenfootingmarks \fi

  %

  \ifx\curchaptername\prevchaptername

    \let\thischapterheading\thischapter

  \else

    % \thischapterheading is the same as \thischapter except it is blank

    % for the first page of a chapter.  This is to prevent the chapter name 

    % being shown twice.

    \def\thischapterheading{}%

  \fi

  %

  \global\setbox\headlinebox = \vbox{\commmonheadfootline \makeheadline}%

  \global\setbox\footlinebox = \vbox{\commmonheadfootline \makefootline}%

  %

  {%

    % Set context for writing to auxiliary files like index files.

    % 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.

    %

    \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.

               % We don't want .vr (or whatever) entries like this:

               % \entry{{\indexbackslash }acronym}{32}{\code {\acronym}}

               % "\acronym" won't work when it's read back in;

               % it needs to be

               % {\code {{\backslashcurfont }acronym}

    \shipout\vbox{%

      % Do this early so pdf references go to the beginning of the page.

      \ifpdfmakepagedest \pdfdest name{\the\pageno} xyz\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 \oddfootingyyy.)

        % The \baselineskip=24pt in plain's \makefootline has no effect.

        \vskip 24pt

        \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 \indexdummies

  \advancepageno

  \ifnum\outputpenalty>-20000 \else\dosupereject\fi

}

\newinsert\margin \dimen\margin=\maxdimen

% Main part of page, including any footnotes

\def\pagebody#1{\vbox to\txipageheight{\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\relax \unvbox#1\relax

\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}}

% Argument parsing

% 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.

% For example, \def\foo{\parsearg\fooxxx}.

%

\def\parsearg{\parseargusing{}}

\def\parseargusing#1#2{%

  \def\argtorun{#2}%

  \begingroup

    \obeylines

    \spaceisspace

    #1%

    \parseargline\empty% Insert the \empty token, see \finishparsearg below.

}

{\obeylines %

  \gdef\parseargline#1^^M{%

    \endgroup % End of the group started in \parsearg.

    \argremovecomment #1\comment\ArgTerm%

  }%

}

% First remove any @comment, then any @c comment.  Also remove a @texinfoc

% comment (see \scanmacro for details).  Pass the result on to \argcheckspaces.

\def\argremovecomment#1\comment#2\ArgTerm{\argremovec #1\c\ArgTerm}

\def\argremovec#1\c#2\ArgTerm{\argremovetexinfoc #1\texinfoc\ArgTerm}

\def\argremovetexinfoc#1\texinfoc#2\ArgTerm{\argcheckspaces#1\^^M\ArgTerm}

% Each occurrence of `\^^M' or `<space>\^^M' is replaced by a single space.

%

% \argremovec might leave us with trailing space, e.g.,

%    @end itemize  @c foo

% This space token undergoes the same procedure and is eventually removed

% by \finishparsearg.

%

\def\argcheckspaces#1\^^M{\argcheckspacesX#1\^^M \^^M}

\def\argcheckspacesX#1 \^^M{\argcheckspacesY#1\^^M}

\def\argcheckspacesY#1\^^M#2\^^M#3\ArgTerm{%

  \def\temp{#3}%

  \ifx\temp\empty

    % Do not use \next, perhaps the caller of \parsearg uses it; reuse \temp:

    \let\temp\finishparsearg

  \else

    \let\temp\argcheckspaces

  \fi

  % Put the space token in:

  \temp#1 #3\ArgTerm

}

% If a _delimited_ argument is enclosed in braces, they get stripped; so

% to get _exactly_ the rest of the line, we had to prevent such situation.

% We prepended an \empty token at the very beginning and we expand it now,

% just before passing the control to \argtorun.

% (Similarly, we have to think about #3 of \argcheckspacesY above: it is

% either the null string, or it ends with \^^M---thus there is no danger

% that a pair of braces would be stripped.

%

% But first, we have to remove the trailing space token.

%

\def\finishparsearg#1 \ArgTerm{\expandafter\argtorun\expandafter{#1}}

% \parseargdef - define a command taking an argument on the line

%

% \parseargdef\foo{...}

%	is roughly equivalent to

% \def\foo{\parsearg\Xfoo}

% \def\Xfoo#1{...}

\def\parseargdef#1{%

  \expandafter \doparseargdef \csname\string#1\endcsname #1%

}

\def\doparseargdef#1#2{%

  \def#2{\parsearg#1}%

  \def#1##1%

}

% Several utility definitions with active space:

{

  \obeyspaces

  \gdef\obeyedspace{ }

  % Make each space character in the input produce a normal interword

  % space in the output.  Don't allow a line break at this space, as this

  % is used only in environments like @example, where each line of input

  % should produce a line of output anyway.

  %

  \gdef\sepspaces{\obeyspaces\let =\tie}

  % If an index command is used in an @example environment, any spaces

  % therein should become regular spaces in the raw index file, not the

  % expansion of \tie (\leavevmode \penalty \@M \ ).

  \gdef\unsepspaces{\let =\space}

}

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

% Define the framework for environments in texinfo.tex.  It's used like this:

%

%   \envdef\foo{...}

%   \def\Efoo{...}

%

% It's the responsibility of \envdef to insert \begingroup before the

% actual body; @end closes the group after calling \Efoo.  \envdef also

% defines \thisenv, so the current environment is known; @end checks

% whether the environment name matches.  The \checkenv macro can also be

% used to check whether the current environment is the one expected.

%

% Non-false conditionals (@iftex, @ifset) don't fit into this, so they

% are not treated as environments; they don't open a group.  (The

% implementation of @end takes care not to call \endgroup in this

% special case.)

% At run-time, environments start with this:

\def\startenvironment#1{\begingroup\def\thisenv{#1}}

% initialize

\let\thisenv\empty

% ... but they get defined via ``\envdef\foo{...}'':

\long\def\envdef#1#2{\def#1{\startenvironment#1#2}}

\def\envparseargdef#1#2{\parseargdef#1{\startenvironment#1#2}}

% Check whether we're in the right environment:

\def\checkenv#1{%

  \def\temp{#1}%

  \ifx\thisenv\temp

  \else

    \badenverr

  \fi

}

% Environment mismatch, #1 expected:

\def\badenverr{%

  \errhelp = \EMsimple

  \errmessage{This command can appear only \inenvironment\temp,

    not \inenvironment\thisenv}%

}

\def\inenvironment#1{%

  \ifx#1\empty

    outside of any environment%

  \else

    in environment \expandafter\string#1%

  \fi

}

% @end foo executes the definition of \Efoo.

% But first, it executes a specialized version of \checkenv

%

\parseargdef\end{%

  \if 1\csname iscond.#1\endcsname

  \else

    % The general wording of \badenverr may not be ideal.

    \expandafter\checkenv\csname#1\endcsname

    \csname E#1\endcsname

    \endgroup

  \fi

}

\newhelp\EMsimple{Press RETURN to continue.}

% 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\*{\unskip\hfil\break\hbox{}\ignorespaces}

% @/ allows a line break.

\let\/=\allowbreak

% @. is an end-of-sentence period.

\def\.{.\spacefactor=\endofsentencespacefactor\space}

% @! is an end-of-sentence bang.

\def\!{!\spacefactor=\endofsentencespacefactor\space}

% @? is an end-of-sentence query.

\def\?{?\spacefactor=\endofsentencespacefactor\space}

% @frenchspacing on|off  says whether to put extra space after punctuation.

%

\def\onword{on}

\def\offword{off}

%

\parseargdef\frenchspacing{%

  \def\temp{#1}%

  \ifx\temp\onword \plainfrenchspacing

  \else\ifx\temp\offword \plainnonfrenchspacing

  \else

    \errhelp = \EMsimple

    \errmessage{Unknown @frenchspacing option `\temp', must be on|off}%

  \fi\fi

}

% @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.

%

% Another complication is that the group might be very large.  This can

% cause the glue on the previous page to be unduly stretched, because it

% does not have much material.  In this case, it's better to add an

% explicit \vfill so that the extra space is at the bottom.  The

% threshold for doing this is if the group is more than \vfilllimit

% percent of a page (\vfilllimit can be changed inside of @tex).

%

\newbox\groupbox

\def\vfilllimit{0.7}

%

\envdef\group{%

  \ifnum\catcode`\^^M=\active \else

    \errhelp = \groupinvalidhelp

    \errmessage{@group invalid in context where filling is enabled}%

  \fi

  \startsavinginserts

  %

  \setbox\groupbox = \vtop\bgroup

    % 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

}

%

% The \vtop 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.  Thus, space below is not quite equal to space

% above.  But it's pretty close.

\def\Egroup{%

    % To get correct interline space between the last line of the group

    % and the first line afterwards, we have to propagate \prevdepth.

    \endgraf % Not \par, as it may have been set to \lisppar.

    \global\dimen1 = \prevdepth

  \egroup           % End the \vtop.

  \addgroupbox

  \prevdepth = \dimen1

  \checkinserts

}

\def\addgroupbox{

  % \dimen0 is the vertical size of the group's box.

  \dimen0 = \ht\groupbox  \advance\dimen0 by \dp\groupbox

  % \dimen2 is how much space is left on the page (more or less).

  \dimen2 = \txipageheight   \advance\dimen2 by -\pagetotal

  % if the group doesn't fit on the current page, and it's a big big

  % group, force a page break.

  \ifdim \dimen0 > \dimen2

    \ifdim \pagetotal < \vfilllimit\txipageheight

      \page

    \fi

  \fi

  \box\groupbox

}

%

% 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

\parseargdef\need{%

  % 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 (and is undocumented).

\let\br = \par

% @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.

\parseargdef\exdent{\hfil\break\hbox{\kern -\exdentamount{\rm#1}}\hfil\break}

% This defn is used inside nofill environments such as @example.

\parseargdef\nofillexdent{{\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'.  Not documented, written for gawk manual.

%

\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 -- \input text of FILE.

%

\def\include{\parseargusing\filenamecatcodes\includezzz}

\def\includezzz#1{%

  \pushthisfilestack

  \def\thisfile{#1}%

  {%

    \makevalueexpandable  % we want to expand any @value in FILE.

    \turnoffactive        % and allow special characters in the expansion

    \indexnofonts         % Allow `@@' and other weird things in file names.

    \wlog{texinfo.tex: doing @include of #1^^J}%

    \edef\temp{\noexpand\input #1 }%

    %