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diff --git a/Master/texmf-dist/tex/latex/cases/cases.sty b/Master/texmf-dist/tex/latex/cases/cases.sty new file mode 100644 index 00000000000..b82f010a02a --- /dev/null +++ b/Master/texmf-dist/tex/latex/cases/cases.sty @@ -0,0 +1,187 @@ +% C A S E S . S T Y ver 2.5 May 2002 +% +% Copyright (C) 1993,1994,1995,2000,2002 by Donald Arseneau +% asnd@triumf.ca +% These macros may be freely transmitted, reproduced, or modified +% provided that this notice is left intact. Sub-equation numbering +% is based on subeqn.sty by Stephen Gildea; most of the rest is based +% on LaTeX's \eqnarray by Leslie Lamport and the LaTeX3 team. +% +% This provides a LaTeX environment {numcases} to produce multi-case +% equations with a separate equation number for each case. There is +% also {subnumcases} which numbers each case with the overall equation +% number plus a letter [8a, 8b, etc.]. The syntax is +% +% \begin{numcases}{left_side} +% case_1 & explanation_1 \\ +% case_2 & explanation_2 \\ +% ... +% case_n & explanation_n +% \end{numcases} +% +% Each case is a math formula, and each explanation is a piece of lr mode +% text (which may contain math mode in \(...\) or $...$). The explanations +% are optional. Equation numbers are inserted automatically, just as for +% the eqnarray environment. In particular, the \nonumber command suppresses +% an equation number and the \label command allows reference to a particular +% case. In a subnumcases environment, a \label in the left_side of the +% equation gives the overall equation number, without any letter. +% +% To use this package, +% include "\usepackage{cases}" after \documentclass. You may also +% specify "\usepackage[subnum]{cases}" to force *all* numcases +% environments to be treated as subnumcases. +% +% Question: Is there a {numcases*} environment for unnumbered cases? +% Answer: There is a {cases} environment in AMS-LaTeX, but it is just as +% convenient to stick with the canonical LaTeX array: +% \[ left side = \left\{ \begin{array}...\end{array} \right. \] +% +% Speaking of AMS-math, they use an entirely different system of equation +% numbering, and this package uses ordinary LaTeX numbering. +% +% - - - - - +% A simple example is: +% \begin{numcases}{|x|=} +% x, & for $x \geq 0$\\ +% -x, & for $x < 0$ +% \end{numcases} +% +% Giving: +% / x for x > 0 (1) +% |x| = < - +% \ -x for x < 0 (2) +% +% - - - - - +% +% Another example is calculating the square root of $c+id$. First compute +% \begin{subnumcases}{\label{w} w\equiv} +% 0 & $c = d = 0$\label{wzero}\\ +% \sqrt{|c|}\,\sqrt{\frac{1 + \sqrt{1+(d/c)^2}}{2}} & $|c| \geq |d|$ \\ +% \sqrt{|d|}\,\sqrt{\frac{|c/d| + \sqrt{1+(c/d)^2}}{2}} & $|c| < |d|$ +% \end{subnumcases} +% Then, using $w$ from eq.~(\ref{w}), the square root is +% \begin{subnumcases}{\sqrt{c+id}=} +% 0 & $w=0$ (case \ref{wzero})\\ +% w+i\frac{d}{2w} & $w \neq 0$, $c \geq 0$ \\ +% \frac{|d|}{2w} + iw & $w \neq 0$, $c < 0$, $d \geq 0$ \\ +% \frac{|d|}{2w} - iw & $w \neq 0$, $c < 0$, $d < 0$ +% \end{subnumcases} +% +% - - - begin definitions - - - + +\ProvidesPackage{cases}[2002/05/02 ver 2.5 ] + +\newenvironment{numcases}[1]% +{$$\numc@opts \setbox\z@\hbox + {\advance\c@equation\@ne\def\@currentlabel{\p@equation\theequation}% local + $\displaystyle {#1\null}\m@th$}% + \numc@setsub + \setbox\tw@\vbox\bgroup + \stepcounter{equation}\def\@currentlabel{\p@equation\theequation}% + \global\@eqnswtrue\m@th \everycr{}\tabskip\numc@left\let\\\@eqncr + \halign to\dimen@ii \bgroup \kern\wd\z@ \kern14\p@ % assume width of brace + \tabskip\z@skip \global\@eqcnt\@ne $\displaystyle{##}$\hfil + &\global\@eqcnt\tw@ \skip@10\p@ \advance\skip@\tw@\arraycolsep \hskip\skip@ + ##\unskip\hfil\tabskip\@centering% \unskip removes space if no explanations + &\global\@eqcnt\thr@@\hbox to\z@\bgroup\hss##\egroup\tabskip\z@skip\cr +}{\@@eqncr \egroup % end \halign, which does not contain first column or brace + \global\advance\c@equation\m@ne +%Measure the natural width of the alignment + \unskip\unpenalty\unskip\unpenalty \setbox\z@\lastbox % grab last line + \nointerlineskip \copy\z@ % then put it back + \global\dimen@i\wd\z@ + \setbox\z@\hbox{\hskip-\numc@left\unhbox\z@}% Measure its natural width + \ifdim \wd\z@<\dimen@i \global\dimen@i\wd\z@ \fi +\egroup% end \vbox (box\tw@, box\z@ is restored to LHS) +\hbox to\dimen@ii{\m@th % assemble the whole equation + \hskip\numc@left + \hbox to\dimen@i{$\displaystyle \box\z@ % parameter #1 + \dimen@\ht\tw@ \advance\dimen@\dp\tw@ % get size of brace + \left\{\vcenter to\dimen@{\vfil}\right.\n@space % make brace + $\hfil}\hskip\@centering % finished first part (filled whole line) + \kern-\dimen@ii % backspace the full width + $\vcenter{\box\tw@}$% overlay the alignment + }% end the \hbox to\dimen@ii +\numc@resetsub +$$\global\@ignoretrue} + +\let\numc@setsub\relax +\let\numc@resetsub\relax + +\def\subnumcases{\let\numc@setsub\subequations + \let\numc@resetsub\endsubequations \numcases} +\let\endsubnumcases\endnumcases + +% declare subequations -- either defining them following the style of +% Gildea's subeqn.sty, or using the syntax of AMS-LaTeX if that is loaded. + +\@ifundefined{c@parentequation}{% No AMS, define subequations from scratch: +% +% These versions of subequations follow the style of Gildea's subeqn.sty, +% but are thoroughly rewritten. +% +% You can change the labelling by redefining \thesubequation, but the names +% of the counters may be confusing: The sub-number is given by counter +% {equation}, while the overall equation number is given by {mainequation}. +% There are two ways to reference the overall equation number: +% through the value of \c@mainequation, as in \Roman{mainequation}, or +% through \themainequation, which gives the text of the normal \theequation. +% Refer to the local sub-number with \c@equation, as in \alph{equation}. +% The default numbering is like 13c, given by: +% +\def\thesubequation{\themainequation\alph{equation}} +% +% Some alternatives: +% \def\thesubequation{\themainequation.\Alph{equation}} % 13.C +% \def\thesubequation{\themainequation-\roman{equation}} % 13-iii +% \def\thesubequation{(\arabic{mainequation}\alph{equation})} % (13c) +% The third alternative should be used if a document style has +% declared \renewcommand{\@eqnnum}{\theequation} and +% \renewcommand{\theequation}{(\arabic{equation})}, which makes +% \ref put parentheses around regular equation numbers automatically. +% +\def\subequations{\refstepcounter{equation}% + \mathchardef\c@mainequation\c@equation + \let\@tempa\protect % * added protection + \def\protect{\noexpand\protect\noexpand}% * + \edef\themainequation{\theequation}\let\theequation\thesubequation + \let\protect\@tempa % * + \global\c@equation\z@} +% +\def\endsubequations{% + \global\c@equation\c@mainequation + \global\@ignoretrue} +% +% \begin{subeqnarray} works like \begin{subequations}\begin{eqnarray}, +% with the added feature that a \label command given given at the very +% beginning of the first entry defines a label for the overall equation +% number. +% +\def\subeqnarray{\subequations\eqnarray\@ifnextchar\label{\@lab@subeqnarray}{}} +\def\endsubeqnarray{\endeqnarray\endsubequations} +\def\@lab@subeqnarray#1#2{\begingroup + \let\@currentlabel\themainequation #1{#2}\endgroup} +% +}{}% AMS \subequations already defined + +\def\numc@left{\@centering} +\def\numc@opts{\dimen@ii\displaywidth} + +\DeclareOption{subnum}{ + \let\numc@setsub\subequations + \let\numc@resetsub\endsubequations } + +\DeclareOption{fleqn}{ + \def\numc@left{\mathindent} + \def\numc@opts{\displaywidth\linewidth + \dimen@ii\linewidth } +} +\ProcessOptions + +\endinput + +% Send problem reports to asnd@triumf.ca + +Test file integrity: ASCII 32-57, 58-126: !"#$%&'()*+,-./0123456789 +:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~ |