%\iffalse % MetaComment
%%
%% + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
%% | Copyright(C) 1997-2010 by F. Bosisio |
%% | |
%% | This program can be redistributed and/or modified under |
%% | the terms of the LaTeX Project Public License, either |
%% | version 1.3 of this license or (at your option) any later |
%% | version. The latest version of this license is in |
%% | http://www.latex-project.org/lppl.txt |
%% | and version 1.3 or later is part of all LaTeX distributions |
%% | version 2005/12/01 or later. |
%% | |
%% | This work has the LPPL maintenance status `maintained'. |
%% | The Current Maintainer of this work is F. Bosisio. |
%% | |
%% | This work consists of files envmath.dtx and envmath.html |
%% | and of the derived files envmath.sty and envmath.pdf. |
%% | |
%% | E-mail: fbosisio@bigfoot.com |
%% | CTAN location: macros/latex/contrib/bosisio/ |
%% + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
%%
%% If you make any improvment, find any bug or have
%% any suggestion, please let me know about it.
%%
%<*package,driver>
%\fi
%
\def\FileName{envmath}
%\iffalse % MetaComment
%</package,driver>
%<*package>
%\fi
\def\fileversion{2.5}
\def\filedate{2010/02/10}
\def\docdate{2005/04/09}
\def\filedescr{Extended math environments (FB)}
%
%\iffalse % MetaComment
%</package>
%<*dtx>
%- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
% This section is the installation driver
%
\def\batchfile{\FileName.dtx}
%
\input docstrip
%
\keepsilent
% \askforoverwritefalse
%
\generateFile{\FileName.sty}{f}{\from{\FileName.dtx}{package}}
%
\generateFile{\FileName.drv}{f}{\from{\FileName.dtx}{driver}}
%
\Msg{******************************************************}
\Msg{*}
\Msg{* To produce the documentation run the}
\Msg{* file `\FileName.drv' through LaTeX.}
\Msg{*}
\Msg{******************************************************}
%
\endbatchfile
%
% End of the installation driver
%- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
%</dtx>
%
% This section is the documentation driver
%
%<+driver>\documentclass[12pt,a4paper]{ltxdoc}
%<+driver> \EnableCrossrefs
%<+driver> \CodelineIndex
%<+driver> \RecordChanges
%<+driver> %\OnlyDescription % Uncomment not to see the implementation
%<+driver>\begin{document}
%<+driver> \DocInput{\FileName.dtx}
%<+driver> \PrintIndex
%<+driver> \PrintChanges
%<+driver>\end{document}
%
% End of the documentation driver
%- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
%<*package>
%\fi
%
% \changes{v0.1}{20 April 1997}{First release (basic environments)}
% \changes{v0.2}{10 May 1997}{Added the ``*-form'' of environments}
% \changes{v1.0}{24 May 1997}{Documentation added}
% \changes{v1.1}{18 October 1997}{``EQNarray'' and ``EqSystem'' environments}
% \changes{v1.2}{5 November 1997}{Options to behave like ``Standard'' LateX}
% \changes{v1.3}{8 November 1997}{Documentation updated}
% \changes{v2.0}{20 December 1997}{Separated from package ``mathcmd''}
% \changes{v2.1}{4 February 1998}{``MultiLine'' and ``EqSystem'' environments
% reimplemented; ``EQNarray'' environment and
% ``CONTINUE'' command made obsolete}
% \changes{v2.2}{6 February 1998}{``@StandartEquation'' deferred
% ``AtBeginDocument''; some ``def'' replaced
% by ``newcommand*''; documentation updated}
% \changes{v2.3}{5 March 1999}{Added copyright notice and changed addresses}
% \changes{v2.4}{9 April 2005}{Usage of the double-quote character (") avoided}
% \changes{v2.5}{10 February 2010}{Package renamed from ``mathenv'' to
% ``envmath'' to avoid name conflicts}
%\iffalse % MetaComment
% The previous change was requested by Karl Berry (karl@freefriends.org)
%\fi
%
% \MakeShortVerb{\|}
%
% \title{Package \texttt{\FileName}\thanks{This is version \fileversion,
% last revised \filedate; documentation date \docdate}}
% \author{F. Bosisio\\\normalsize E-mail: \texttt{fbosisio@bigfoot.com}}
% \date{\filedate}
% \maketitle
%
% \begin{abstract}
% Documentation for the package \texttt{\FileName}.
% \end{abstract}
%
% \section{Introduction}
% This package provides some useful math-commands and enviroments,
% which are simpler to use and prettier then their standard \LaTeX{}
% counterpart.
%
% In particular some commands are redefined\footnote{See the options
% in next section if you don't want these comand to be redefined}, so
% care should be taken, expecially when including this package in an
% already existent \LaTeX{} file.
%
% \noindent
% The redefined commands are:\\
% |\(|, |\)|, |\[|, |\]|, |\{| and |\}| \\
% The effect of ``|\(| \dots |\)|'' can still be achieved by the
% \LaTeX{} equivalent commands ``|\begin{math}| \dots |\end{math}|''
% or ``|$| \dots |$|''.
%
% \noindent
% Similarly, the effect of ``|\[| \dots |\]|'' can be achieved by
% the \LaTeX{} equivalent commands
% ``|\begin{displaymath}| \ldots |\end{displaymath}|''
% or ``|$$| \dots |$$|''.
%
% \noindent
% The ``|\{|'' and ``|\}|'' commands are the more error-prone, since
% one may try to use ``|\left\{|'', which now is incorrect, because
% the ``|\{|'' command already contains a ``|\left|'' declaration.
% In the rare occasions where a brace of normal size is needed, one
% can use the \LaTeX{} commands ``|\lbrace|'' and ``|\rbrace|''
%
% \noindent
% Also the ``|equation|'' environment has been changed, but it is
% completly compatible with the original definition, so it should
% be safe, perhaps except when the first character of the equation
% is an open square bracket or it is placed in a moving argument:
% in fact, the new version of this command is fragile, and this is
% true also for most of the commands defined by this package.
%
% \section{Backward compatibility}
% The package has been renamed from ``|mathenv|'' to ``|envmath|'',
% in order to avoid conflicts with another package with the same name:
% if you were using the ``old'' package, you need to change your \LaTeX{}
% files in order to include the new ones.\\
% Alternatively, you can also rename the package to give it the ``old''
% name (you need to change also the ``|\def\FileName{...}|'' line inside
% the ``|sty|''-file), but you must take care not to have another package
% with the same name installed on your system.
%
% \section{The options}
% At now, five options are available with the \texttt{\FileName}
% package.
%
% \noindent
% The ``|RedefEquation|''/``|StdEquation|'' and
% ``|RedefBrackets|''/``|StdBrackets|'' options control
% whether the ``|equation|'' environment and the brace commands
% ``|\(|'', ``|\(|'', ``|\)|'', ``|\[|'', ``|\]|'', ``|\{|'' and ``|\}|
% should be redefined or retain their original \LaTeX{} meaning.
% More precisely, ``|RedefEquation|'' (default) redefines the
% ``equation'' environment to have an optional argument (used as a
% label), while ``|StdEquation|'' leaves it unchanged. In the first
% case, the ``equation'' environment will be equivalent to the
% ``Equation'' environment (capitalized!) described below, whereas in
% the second case they will be different.
% Similarly, the ``|RedefBrackets|'' option (default) makes the
% brackets command to be redefined, whilst ``|StdBrackets|'' leave
% them their original meaning.
% Also a ``|Standard|'' option exists, which amounts to specify both
% the ``|StdEquation|'' and ``|StdBrackets|'' options, thus making the
% package fully standard, which may be useful when sending your
% \LaTeX{} files to someone else.
%
% \section{Math-mode environments}
% This package provides three math-mode environments, each with a
% ``*-form'' which does not generates numbers.
%
% \subsection{The \texttt{Equation} environment}
% The ``|Equation|'' environment has an optional argument
% which is used as a label to reference it.
% \begin{verbatim}
% \begin{Equation}[label]
% ...
% \end{Equation}
% \end{verbatim}
% If the ``|RedefEquation|'' option is in effect (default),
% then the ``|equation|'' environment is redefined to have
% the same optional argument as ``|Equation|''.
%
% There is also a *-form, which does not generate a number
% (so this *-form is really a ``displaymath'' and not an
% equation, but it has been added for simmetry and for making
% it easier to add or remove the number to a formula).
%
% \noindent
% The *-form has an optional argument like the non-* form,
% which is disregarded by the environment and is added only
% for simmetry reasons.
% \begin{verbatim}
% \begin{equation*}[disregarded-label]
% ...
% \end{equation*}
% \end{verbatim}
%
% \subsection{The \texttt{MultiLine} equation environment}
% The ``|MultiLine|'' environment is intended for formulas
% that don't fit on a single line, and so must be broken
% across lines.
%
% \noindent
% As for the |Equation| environment above, it has an optional
% argument which is used as a label.
%
% \noindent
% All the lines but the first are automatically indented by
% the lenght ``|\MultiLineIndent|'', which is rougthly what
% one expects, but can be changed at any time by the user
% with ``|\setlenght{\MultiLineIndent}{...}|''.
% You can also control the alignment of the continuation rows
% by placing an optional |&| in the first row: is such a case
% all the others line will \emph{not} be indented
% by ``|\MultiLineIndent|'' but wil behave \emph{as if} there
% there were an ampersand in front of them (i.e. they will be
% left-aligned at the right of the \& in the first row).
%
% \noindent
% Each line but the last must end with a ``|\\|'' command
% (which can have an optional argument to add some vertical
% space between lines).
% When the line is broken in the middle (e.g. after a ``+''
% sign) and not at the end (i.e. after a ``='' or similar), the
% *-form ``|\\*|'' may be used to indicate the line-break, the
% difference being in an extra space added at the beginning of
% the next line.
% The width of a thise space defaults to 1em and can be changed
% by the user with ``|\setlenght{\MultiLineStarIndent}{...}|''.
%
% \begin{verbatim}
% \begin{MultiLine}[label]
% ... [&]= ... = \\
% = ... + \\*
% + ... = \\
% = ...
% \end{MultiLine}
% \end{verbatim}
%
% Also this environment has a *-form which differs only in that
% it does not generate an equation number.
% \begin{verbatim}
% \begin{MultiLine*}[disregarded-label]
% ... [&]= ... = \\
% = ... + \\*
% + ... = \\
% = ...
% \end{MultiLine*}
% \end{verbatim}
%
% \subsection{The \texttt{System} environment}
% The ``|System|'' environment is used for grouping a set of
% equations together inside a left brace, with one only
% equation number.
%
% \noindent
% Again there is an optional argument to indicate a label and
% each equation is separated by a ``|\\|'' or ``|\\*|'' command,
% as for the ``|MultiLine|'' environment.
%
% \noindent
% The rows (except the ones ended with the *-form ``|\\*|'')
% may optionally contain one ``|&|'', which is usually used
% when some text should be added to the equation.
% \begin{verbatim}
% \begin{System}[label]
% ... = ... [& ...] \\
% ... = ... + \\*
% + ... [& ...] \\
% ... = ... [& ...]
% \end{System}
% \end{verbatim}
%
% A *-form which does not generate any number is also provided.
% \begin{verbatim}
% \begin{System*}[disregarded-label]
% ... = ... [& ...] \\
% ... = ... + \\*
% + ... [& ...] \\
% ... = ... [& ...]
% \end{System*}
% \end{verbatim}
%
% \subsection{The \texttt{EqSystem} environment}
% The ``|EqSystem|'' environment is used for grouping a set of
% equations together inside a left brace, each with its own
% equation number.
%
% \noindent
% Again there is an optional argument to indicate a label and
% each equation is separated by a ``|\\|'' or ``|\\*|'' command.
%
% \noindent
% The rows may optionally contain one ``|&|'', which is
% usually used when some text should be added to the equation.
% \begin{verbatim}
% \begin{EqSystem}[label]
% ... = ... [& ...] \\ % (1.1)
% ... = ... + \\* % (1.2)
% + ... [& ...] \\ % (1.3)
% ... = ... [& ...] % (1.4)
% \end{EqSystem}
% \end{verbatim}
%
% A *-form is also provided: it differs in that each equation
% is numbered with the same number but with a lowercase letter
% added, i.e. like (1.1a), (1.1b), etc. instead of (1.1),
% (1.2) and so on.
% \begin{verbatim}
% \begin{EqSystem*}[label]
% ... = ... [& ...] \\ % (1.5a)
% ... = ... + \\* % (1.5b)
% + ... [& ...] \\ % (1.5c)
% ... = ... [& ...] % (1.5d)
% \end{EqSystem*}
% \end{verbatim}
% In both cases, if the optional argument is present, each
% equation can be referenced by |\ref{<label>:a}|,
% |\ref{<label>:b}|, \dots, where |<label>|, stands for
% the string used as optional argument.
% In the case of the *-form, a reference of the kind
% |\ref{<label>}| will print the equation number without
% any letter, thus referring to the system as a whole,
% whereas such a reference is meaningless (and indeed does
% not exists) when dealing with the non *-form.
%
%
% \section{Math-mode commands}
% In addition to the previously mentioned environments, the
% \texttt{\FileName} package defines also some of math-mode
% commands which considerably simplify the use of adjustable-size
% parentheses.
%
% \noindent
% The ``|\(|'', ``|\[|'', ``|\{|'', ``|\)|'', ``|\]|''
% and ``|\}|'' generates the corresponding parenthesis but
% with a ``|\left|'' or ``|\right|'' declaration
% (respectively) added, so they must come in matched pairs or
% coupled with a ``|\left.|'' or ``|\rigtht.|'' or another
% adjustable-size delimiter.
%
% \StopEventually{}
% \newpage
% \section{Implementation}
%
% \begin{macrocode}
%%
\NeedsTeXFormat{LaTeX2e}[1995/12/01]
\ProvidesPackage{\FileName}[\filedate\space v\fileversion\space\filedescr]
%%
\newif\if@Redefine@Equation@
\DeclareOption{RedefEquation}{\@Redefine@Equation@true}
\DeclareOption{StdEquation}{\@Redefine@Equation@false}
%%
\newif\if@Redefine@Brackets@
\DeclareOption{RedefBrackets}{\@Redefine@Brackets@true}
\DeclareOption{StdBrackets}{\@Redefine@Brackets@false}
%%
\DeclareOption{Standard}{\@Redefine@Equation@false\@Redefine@Brackets@false}
%%
\ExecuteOptions{RedefEquation,RedefBrackets}
% \end{macrocode}
%
% The ``|\ProcessOptions*|'' command was used here instead of
% ``|\ProcessOptions*|'' in order to process the options in the
% ``|\usepackage|'' order, rather than in the declaration order
% \begin{macrocode}
%%
\ProcessOptions*
% \end{macrocode}
%
% \begin{macro}{\StartMath@Err}
% The ``|\StartMath@Err|'' prints an error message if used in math-mode
% (saying that you can't use the command passed to it as an argument in
% math-mode); otherwise it just enters math-mode through a |$$|.
% It is used by the *-form of the math-environments to prevent
% their use in math-mode.
% \begin{macrocode}
%%
\newcommand*\StartMath@Err[1]{%
\ifmmode\PackageError{\FileName}{%
You can't use environment ``#1'' in math mode}{%
You probably used ``\string\end{#1}'' without a previous ``\string\begin{#1}''.}%
\else$$\fi%
}
% \end{macrocode}
% \end{macro}
%
% \begin{environment}{Equation}
% The definition of the original ``|equation|'' environment is first saved
% in the ``|\@StandardEquation|'' command.
% Then the ``|\@LabelledEquation|'' command is defined as an |equation|
% with a label.
% The |Equation| command simply calls ``|\@LabelledEquation|'' or
% ``|\@StandardEquation|'', depending on the presence or absence of the
% optional argument (indicated by the square bracket).
% \begin{macrocode}
%%
\AtBeginDocument{%
\let\@StandardEquation=\equation
}
\def\@LabelledEquation[#1]{\@StandardEquation\label{#1}}
\newenvironment{Equation}{%
\@ifnextchar[{\@LabelledEquation}{\@StandardEquation}%
}{%
\endequation%
}
% \end{macrocode}
%
% If the ``|RedefEquation|'' option is in effect, |equation| is defined
% to be the same as |Equation|.
% The actual definition of the |equation| environment is deferred at the
% ``|\begin{document}|'' in order to minimize the possibility of
% conflicts with other packages.
% \begin{macrocode}
\if@Redefine@Equation@
\AtBeginDocument{\let\equation=\Equation}
\fi
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{equation*}
% The command ``|\Equation@Star|'' simply enters math-mode (via the
% ``|\StartMath@Err|'' command).
% The definition of ``|equation*|'' is deferred at the
% ``|\begin{document}|'' so that this definition takes precedence over
% the analogue one from the ``|amsmath|'' package, if both are included.
% The command ``|\global\@ignoretrue|'' in the definition of
% ``|\end{equation*}|'' prevents spurious spaces at the beginning of next
% line.
% \begin{macrocode}
%%
\def\Equation@Star[#1]{\StartMath@Err{equation*}}
\AtBeginDocument{%
\@namedef{equation*}{\@ifnextchar[{\Equation@Star}{\Equation@Star[]}}%
\@namedef{endequation*}{$$\global\@ignoretrue}%
}
% \end{macrocode}
% \end{environment}
%
% \begin{macro}{\ARRAY@CR}
% The original definition of ``|\@arraycr|'' is saved in the command
% ``|\@ArrayCR|''.
% Then ``|\ARRAY@CR|'' is defined to do the same job of ``|\@arraycr|''
% and add a ``|\displaystyle|'' declation at the beginning of next row.
% \begin{macrocode}
%%
\let\@ArrayCR=\@arraycr
\def\@ArrayCR@quadra[#1]{\@ArrayCR[#1]\displaystyle}
\def\@ArrayCR@star@quadra[#1]{%
\@ArrayCR[#1]\displaystyle\mbox{\hspace{\SystemStarIndent}}%
}
\def\@ArrayCR@star*{%
\@ifnextchar[{\@ArrayCR@star@quadra}{%
\@ArrayCR\displaystyle\mbox{\hspace{\SystemStarIndent}}}}%
\newcommand*{\ARRAY@CR}{\@ifnextchar*{\@ArrayCR@star}{%
\@ifnextchar[{\@ArrayCR@quadra}{\@ArrayCR\displaystyle}}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\MakeAmper@Active}
% Makes ``\&'' active (instead of a tab marker), giving
% it the meaning specified by the argument.
% \begin{macrocode}
%%
\newcommand*\MakeAmper@Active[1]{
\global\def\@AMPERSAND{#1}%
\begingroup%
\catcode`\~\active \lccode`\~`\&%
\lowercase{%
\global\expandafter\let
\csname ac\string\&\endcsname~%
\gdef~{\@AMPERSAND}}%
\endgroup%
\global\catcode`\&\active%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\MakeAmper@Tab}
% Restores ``\&'' to its original meaning (a tab marker).
% \begin{macrocode}
%%
\newcommand*\MakeAmper@Tab{\global\catcode`\&=4}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\OneShot@Amper}
% Makes ``\&'' active for one occurrence only: when encountered, the
% code in the first argument is executed, then ``\&'' is restored to
% its original meaning, a tab marker is inserted, and finally the
% code in the second argument is executed.
% \begin{macrocode}
%%
\newcommand*\OneShot@Amper[2]{%
\MakeAmper@Active{#1\expandafter\MakeAmper@Tab}%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\MultiLineIndent}
% The length ``|\MultiLineIndent|'' represents the amount of spece by
% which each line but the first of a ``|MultiLine|'' environment is
% indented. It defaults to 1.7em, which is roughtly equal to the width
% of a character followed by an equal sign (e.g.: ``|A = |'' ).
% \begin{macrocode}
%%
\newlength\MultiLineIndent
\setlength{\MultiLineIndent}{1.7em}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\MultiLineStarIndent}
% The length ``|\MultiLineStarIndent|'' represents the amount of spece by
% which each line following a ``|\\*|'' in a ``|MultiLine|'' environment is
% indented. It defaults to 1em, which is roughtly equal to the width
% of a an equal sign (e.g.: ``|=|'' ).
% \begin{macrocode}
%%
\newlength\MultiLineStarIndent
\setlength\MultiLineStarIndent{1em}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\@MultiLineCR}
% The ``|\@MultiLineCR|'' command does the original job of ``|\@arrycr|''
% (saved in ``|\ArrayCR|'') and then executes the ``|\ML@EveryRow|''
% command.
% In the *-form it also adds a space equal to ``|\MultiLineStarIndent|''.
% The splitting in subcommands is required in order to pass the optional
% argument to ``|\@ArrayCR|'' and not to the last executed command.
% \begin{macrocode}
%%
\newcommand*\@MultiLineCR{%
\@ifnextchar*{\MLineCR@star}{%
\@ifnextchar[{\MLineCR@quadra}{\@ArrayCR\ML@EveryRow}}%
}
\def\MLineCR@star*{%
\@ifnextchar[{\MLineCR@star@quadra}{%
\@ArrayCR\ML@EveryRow\hspace{\MultiLineStarIndent}}%
}
\def\MLineCR@star@quadra[#1]{%
\@ArrayCR[#1]%
\ML@EveryRow%
\hspace{\MultiLineStarIndent}%
}
\def\MLineCR@quadra[#1]{\@ArrayCR[#1]\ML@EveryRow}
% \end{macrocode}
%
% The ``|MultiLine|'' environment starts by setting ``|\ML@EveryRow|''
% to be equivalent to ``|\@MultiLINEcr|'', so that this command is
% executed at the end of the first row.
% It checks the |\catcode| of \& and redefines ``|\ML@EveryRow|''
% accordingly: if \& is a tab marker (|\catcode|=4), an ampersand has
% occurred in the first row, so that each row must begin itself with
% an ampersand; otherwise (i.e. if the |\catcode| of \& is \emph{active})
% no ampersand were found in the first row, so that each line must begin
% with a space equal to ``|\MultiLineStarIndent|''.
% \begin{macrocode}
\newcommand*\@MultiLINEcr{%
\ifnum\catcode`\&=4%
\global\def\ML@EveryRow{&\displaystyle\mbox{}}%
\else%
\MakeAmper@Tab%
\global\def\ML@EveryRow{\displaystyle\mbox{\hspace{\MultiLineIndent}}}%
\fi%
\ML@EveryRow%
}
% \end{macrocode}
% \end{macro}
%
% \begin{macro}{\CONTINUE}
% The command ``|\CONTINUE|'' is obsolete: you should use ``|\\*|'' instead.
% \begin{macrocode}
%%
\newcommand*{\CONTINUE}{%
\PackageError{\FileName}{%
Command ``\string\CONTINUE'' is obsolete: use ``\string\\*'' instead}{%
You'd better correct your input file as stated above,\MessageBreak%
but if you press ENTER everything will work for the moment.}%
\MLineCR@star*%
}
% \end{macrocode}
% \end{macro}
%
% \begin{environment}{MultiLine}
% The internal commad ``|\Start@MultiLine|'' is used by the ``|MultiLine|''
% and ``|MultiLine*|'' environments.
% It makes \& add a ``|\displaystyle|'' declaration.
% It also changes the meaning of ``|\\|'' to ``|\@MultiLineCR|'', sets
% ``|\ML@EveryRow|'' to its default value ``|\@MultiLINEcr|'' and then
% starts an ``|array|'' environment (we already are in math-mode
% here) with one only column which is left aligned.
% Finally, if there is an optional argument it is used as a ``|\label|''
% or ignored, depending on the current meaning of ``|\@LABEL|'' (which
% is the same as ``|\label|'' in the standard form and does nothing in
% the *-form).
% \begin{macrocode}
%%
\newcommand*\Start@MultiLine{%
\@ifnextchar[{\Start@MultiLine@quadra}{\Start@MultiLine@no}%
}
%%
\def\Start@MultiLine@quadra[#1]{\@LABEL{#1}\Start@MultiLine@no}
%%
\newcommand*\Start@MultiLine@no{%
\OneShot@Amper{}{\displaystyle}%
\let\@arraycr=\@MultiLineCR%
\let\ML@EveryRow=\@MultiLINEcr%
\begin{array}{l@{\hspace{0.3em}}l}%
\displaystyle%
}
% \end{macrocode}
%
% The internal command ``|\Stop@MultiLine|'' is used by the ``|MultiLine|''
% and ``|MultiLine*|'' environments.
% It simply closes the ``|array|'' environment anr restores ``|\@arrycr|''
% to its original meaning.
% \begin{macrocode}
%%
\newcommand*\Stop@MultiLine{%
\end{array}%
\let\@arraycr=\@ArrayCR%
\MakeAmper@Tab% % For the case no ``\\'' is used
}
% \end{macrocode}
%
% The ``|MultiLine|'' environment invokes ``|\Start@MultiLine|'' and
% ``|\Stop@MultiLine|'' inside an ``|equation|'' environment.
% \begin{macrocode}
%%
\newenvironment{MultiLine}{%
\let\@LABEL=\label%
\@StandardEquation%
\Start@MultiLine%
}{%
\Stop@MultiLine%
\endequation%
\global\@ignoretrue%
}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{MultiLine*}
% The ``|\MultiLine@Star|'' command issues an error message if used inside
% math mode, while when in text mode starts a ``|displaymath|'' environment
% (throught the ``|$$|'' command) in which a ``|\Start@MultiLineEq|'' command
% is issued (so it is the same as ``|\Label@MultiLineEq|'', but with
% ``|\equation|'' substituted by ``|$$|'').
% \begin{macrocode}
%%
\@namedef{MultiLine*}{\ifmmode\Not@MathErr{MultiLine*}\else$$\fi%
\def\@LABEL##1{}%
\Start@MultiLine%
}
\@namedef{endMultiLine*}{\Stop@MultiLine$$\global\@ignoretrue}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{System}
% The ``|\@System@Def|'' command is the kernel of the ``|System|'' and
% ``|System*|'' environments.
% It redefines ``|\@arraycr|'' so that ``|\\|'' not only ends the
% line but also adds a ``|\displaystyle|'' declaration.
% Then it draws an adjustable-size left brace, which will be as big as
% the system requires.
% Finally, a two-column array environment with a ``|\qquad|'' space
% between the columns is started and a ``|\displaystyle|'' declaration
% is added to the first row.
% \begin{macrocode}
%%
\newcommand*\@System@Def{%
\let\@arraycr=\ARRAY@CR%
\left\lbrace%
\begin{array}{l@{\qquad}l@{}}%
\displaystyle%
}
% \end{macrocode}
% The ``|\Label@System|'' commands opens an equation environment, issues
% a ``|\label|'' command for cross-referencing, and then calls the
% command ``|\@System@Def|'' defind above.
% \begin{macrocode}
\def\Label@System[#1]{\@StandardEquation\label{#1}\@System@Def}
% \end{macrocode}
% The ``|\begin{System}|'' command does the same things, skipping the
% ``|\label|'' command if there isn't the optional parameter.
% The ``|\end{System}|'' command closes the array, puts an invisible
% delimiter (``|\right.|'') which pairs with the left brace of the
% ``|\@System@Def|'' command, restores ``|\@arraycr|'' to its original
% meaning, ends the equation, and prevents spurious spaces by issuing
% the command ``|\global\@ignoretrue|''.
% \begin{macrocode}
\newenvironment{System}{%
\@ifnextchar[{\Label@System}{\@StandardEquation\@System@Def}%
}{%
\end{array}%
\right.%
\endequation%
\let\@arraycr=\@ArrayCR%
\global\@ignoretrue%
}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{System*}
% The ``|\System@Star|'' command generates en error message when used in
% math-mode, and calls ``|\@System@Def|'' inside a ``|displaymath|''
% environment (the ``|$$|'') when used in text-mode.
% \begin{macrocode}
%%
\def\System@Star[#1]{\StartMath@Err{System*}\@System@Def}
% \end{macrocode}
% The ``|System*|'' environment is the same as ``|System|'', but with
% ``|\begin{equation}|$\ldots$|\end{equation}|'' substituted by
% ``|$$|\ldots|$$|''.
% \begin{macrocode}
\@namedef{System*}{\@ifnextchar[{\System@Star}{\System@Star[]}}
\@namedef{endSystem*}{\end{array}\right. $$\let\@arraycr=\@ArrayCR \global\@ignoretrue}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{EQNarray}
% The |EQNarray| environment is only for backward compatibility:
% use the |equationarry| environment from package |eqnarray| if
% you need more control than an |eqnarray| environment allows.
% \begin{macrocode}
%%
\newenvironment{EQNarray}{%
\PackageError{\FileName}{Environment ``EQNarray'' is obsolete}{%
Use the ``equationarry'' environment from the ``eqnarray'' package instead!}%
\eqnarray%
}{%
\endeqnarray%
}
% \end{macrocode}
% \end{environment}
% \begin{macro}{\SystemColSep,\SystemBraceSep,\SystemStarIndent}
% \begin{macrocode}
%%
\newlength\SystemColSep
\setlength\SystemColSep{2em}
%%
\newlength\SystemBraceSep
\setlength\SystemBraceSep{3pt}
%%
\newlength\SystemStarIndent
\setlength\SystemStarIndent{2em}
% \end{macrocode}
% \end{macro}
%
% \begin{environment}{EqSystem}
% \begin{macrocode}
%%
\newsavebox{\SysRow@Box}
\newlength\ColOne@Width
\newlength\ColTwo@Width
\newlength\SysCol@TmpWidth
%%
\newcommand*\Start@EqSysRow{%
\OneShot@Amper{%
$\end{lrbox}%
\settowidth\SysCol@TmpWidth{\usebox{\SysRow@Box}}%
\ifnum\SysCol@TmpWidth>\ColOne@Width\global\setlength\ColOne@Width\SysCol@TmpWidth\fi%
\usebox{\SysRow@Box}%
}{%
\begin{lrbox}{\SysRow@Box}$\displaystyle%
}%
\begin{lrbox}{\SysRow@Box}$\displaystyle%
}
%%
\newcommand*\Stop@EqSysRow{%
$\end{lrbox}%
\settowidth\SysCol@TmpWidth{\usebox{\SysRow@Box}}%
\ifnum\catcode`\&=4%
\ifnum\SysCol@TmpWidth>\ColTwo@Width\global\setlength\ColTwo@Width\SysCol@TmpWidth\fi%
\else%
\MakeAmper@Tab%
\ifnum\SysCol@TmpWidth>\ColOne@Width\global\setlength\ColOne@Width\SysCol@TmpWidth\fi%
\fi%
\usebox{\SysRow@Box}%
}
%%
\def\@EqSystCR@star@quadra[#1]{%
\Sys@@eqncr%
\noalign{\penalty\@eqpen\vskip #1\relax}%
\Start@EqSysRow%
\mbox{\hspace{\SystemStarIndent}}%
}
%%
\def\@EqSystCR@star*{%
\global\@eqnswfalse%
\@ifnextchar[{\@EqSystCR@star@quadra}{%
\Sys@@eqncr\Start@EqSysRow\mbox{\hspace{\SystemStarIndent}}}%
}
%%
\def\@EqSystCR@quadra[#1]{%
\Sys@@eqncr%
\noalign{\penalty\@eqpen\vskip #1\relax}%
\Start@EqSysRow%
}
%%
\newcommand*\EqSyst@CR{%
\Stop@EqSysRow%
\@ifnextchar*{\@EqSystCR@star}{%
\@ifnextchar[{\@EqSystCR@quadra}{\Sys@@eqncr\Start@EqSysRow}}%
}
%%
\let\Label@EqSystem=\relax
%%
\newcommand*\Sys@@eqncr{%
\let\reserved@a\relax%
\ifcase\@eqcnt\def\reserved@a{& &}% %% \@eqcnt = 0
\or\def\reserved@a{&}% %% \@eqcnt = 1
\else% %% \@eqcnt > 1
\let\reserved@a\@empty%
\PackageError{\FileName}{Too many columns in EqSystem environment}{%
You can use at most one ``&'' in each row of an ``EqSystem'' environment.}%
\fi%
\reserved@a%
\if@eqnsw\Label@EqSystem\@eqnnum\stepcounter{equation}\fi%
\global\@eqnswtrue%
\global\@eqcnt\z@%
\cr%
}
%%
\newenvironment{EqSystem}[1][\relax]{%
\setcounter{EqSys@counter}{0}%
\def\Label@EqSystem{#1}%
\def\@tempa{\relax}%
\ifx\Label@EqSystem\@tempa\else%
\def\Label@EqSystem{\stepcounter{EqSys@counter}\label{#1:\alph{EqSys@counter}}}%
\fi%
\BEGIN@EqSystem%
}{%
\Stop@EqSysRow%
%%%-------------------- \endEQNarr@y ----------------------%
\Sys@@eqncr%
\egroup%
\global\advance\c@equation\m@ne%
$$%
%%%--------------------------------------------------------%
\vspace*{-\belowdisplayskip}%
\end{minipage}%
\advance\ColTwo@Width\ColOne@Width%
\advance\ColTwo@Width\SystemColSep%
\setlength\SysCol@TmpWidth\displaywidth%
\global\advance\SysCol@TmpWidth-\ColTwo@Width%
\global\divide\SysCol@TmpWidth\tw@%
\global\advance\SysCol@TmpWidth\ColTwo@Width%
\global\advance\SysCol@TmpWidth\SystemBraceSep% %% Space around left-brace
\global\advance\SysCol@TmpWidth 1em% %% ~= Left-brace size
\hspace{-\SysCol@TmpWidth}%
\right\lbrace%
\advance\SysCol@TmpWidth-1em% %% ~= Left-brace size
\hspace*{\SysCol@TmpWidth}%
$$\global\@ignoretrue%
}
%%
\newcommand*\BEGIN@EqSystem{%
\setlength\ColOne@Width\z@%
\setlength\ColTwo@Width\z@%
$$\left.%
\begin{minipage}{\displaywidth}%
\vspace*{-\abovedisplayskip}%
%%%-------------------------- \EQNarr@y -------------------%
\stepcounter{equation}%
\let\@currentlabel=\theequation%
\global\@eqnswtrue%
\global\@eqcnt\z@%
\tabskip\@centering%
\let\\=\EqSyst@CR%
$$\halign to \displaywidth\bgroup%
\tabskip\z@{##}\hfil%
&\global\@eqcnt\@ne%
\hspace{\SystemColSep}{##}\hfil%
\tabskip\@centering%
&\llap{##}\tabskip\z@\cr%
%%%--------------------------------------------------------%
\Start@EqSysRow%
}
% \end{macrocode}
% \end{environment}
%
% \begin{environment}{EqSystem*}
% \begin{macrocode}
%%
\newcounter{EqSys@counter}
%%
\newcommand*\EqSystem@Star[1][\relax]{%
\stepcounter{equation}%
\setcounter{EqSys@counter}{\value{equation}}%
\def\Label@EqSystem{#1}%
\def\@tempa{\relax}%
\ifx\Label@EqSystem\@tempa\else%
\let\@currentlabel=\theequation%
\label{#1}%
\def\Label@EqSystem{\label{#1:\alph{equation}}}%
\fi%
\let\INNER@theEQUATION=\theequation%
\xdef\inner@theEQUATION{\theequation}%
\def\theequation{\inner@theEQUATION\alph{equation}}%
\setcounter{equation}{0}%
\BEGIN@EqSystem%
}
%%
\@namedef{EqSystem*}{\EqSystem@Star}
%%
\@namedef{endEqSystem*}{%
\endEqSystem%
\setcounter{equation}{\value{EqSys@counter}}%
\global\let\theequation=\INNER@theEQUATION%
}
% \end{macrocode}
% \end{environment}
%
% The \LaTeX{} environments \texttt{math} and \texttt{displaymath}
% are redefined so that they will not be affected by the subsequent
% redefinition of the brackets commands.
% The redefinition of the brackets commands is deferred at the
% |\begin{document}|, so that other packages may use the original
% definitions and cannot override the new ones.
% It only takes place if the ``|RedefBrackets|'' option is in effect.
% \begin{macrocode}
\if@Redefine@Brackets@
\AtBeginDocument{%
\let\math=\(
\let\endmath=\)
\let\displaymath=\[
\let\enddisplaymath=\]
\renewcommand*{\(}{\left(}%
\renewcommand*{\)}{\right)}%
\renewcommand*{\[}{\left[}%
\renewcommand*{\]}{\right]}%
\renewcommand*{\{}{\left\lbrace}%
\renewcommand*{\}}{\right\rbrace}%
}
\fi
% \end{macrocode}
%
%\iffalse % MetaComment
%<*package>
%\fi
%
% \CheckSum{653}
% \Finale
%
\endinput