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diff --git a/Master/texmf-dist/source/latex/mh/empheq07.dtx b/Master/texmf-dist/source/latex/mh/empheq07.dtx new file mode 100644 index 00000000000..09bb2c6f3c0 --- /dev/null +++ b/Master/texmf-dist/source/latex/mh/empheq07.dtx @@ -0,0 +1,1402 @@ +%\iffalse meta-comment +% File `empheq07.dtx'. +% Copyright 2002-2004 Morten H\o gholm. +% moho01ab@student.cbs.dk +% +% It may be distributed and/or modified under the +% conditions 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 distributions of LaTeX +% version 2003/12/01 or later. +% +% This work has the LPPL maintenance status "maintained". +% +% The Current Maintainer of this work is Morten H\o gholm. +% +% This work consists of the files empheq07.dtx and empheq07.ins +% and the derived file empheq07.sty. +% +%<*dtx> + \ProvidesFile{empheq07.dtx} +%</dtx> +%<package>\NeedsTeXFormat{LaTeX2e} +%<package>\ProvidesPackage{empheq07} + [2004/07/27 v0.7d Emphasizing equations (MH)] +%<*driver> +\documentclass[a4paper]{ltxdoc} +\usepackage{empheq07} +\usepackage{color,fancybox,ifpdf} +\ifpdf\else + \usepackage{pstricks} +\fi +\definecolor{lightblue}{rgb}{.8, .8, 1} +\OnlyDescription +\begin{document} +\DocInput{empheq07.dtx} +\end{document} +%</driver> +% \fi +% \DeclareRobustCommand{\mode}[1]{\texttt{#1}} +% \DeclareRobustCommand{\env}[1]{\textsf{#1}} +% \DeclareRobustCommand{\pkg}[1]{\texttt{#1}} +% \DeclareRobustCommand{\EQ}{\pkg{empheq07}} +% +% \changes{v0.7d}{2004/07/27}{Changed name to \pkg{empheq07} by request +% of Robin Fairbairns} +% +% \changes{v0.7c}{2004/04/01}{Separated \pkg{empheq} and +% \pkg{empheq-obsolete}} +% +% \changes{v0.7b}{2004/03/13}{Upgraded license to LPPL version 1.3. +% The package is still obsolete} +% +% \changes{v0.7a}{2004/02/15}{This package is now obsolete and has +% changed its name to \pkg{empheq-obsolete}} +% +% \changes{v0.6a}{2003/01/28}{Minor updates to documentation.} +% +% \changes{v0.5}{2002/12/30}{First experimental and very limited release} +% \newif\ifBonusExample +% \ifpdf\else +% \BonusExampletrue +% \fi +% \GetFileInfo{empheq07.dtx} +% \CheckSum{1273} +% \title{The \EQ\ package\thanks{This file +% has version number \fileversion, last +% revised \filedate.}\\Emphasizing equations in \LaTeXe +% \thanks{Thanks to Lars Madsen for asking for the subtle feature +% that evolved into this package.}} +% \author{Morten H\o gholm} +% \date{\filedate} +% +% \maketitle +% +% +% \begin{abstract} +% \noindent The \EQ\ package automatically detects several \pkg{amsmath} +% environments and the size of the displayed math material. The user +% interface makes it easy to add various kinds of visual markup to +% these equations. +% \end{abstract} +% \tableofcontents +% \section{Important Notice} +% +% This package (\EQ\ \fileversion) is no longer supported. See the +% documentation of \pkg{empheq} for more details. +% +% +% \section{Introduction} +% Users who have wanted to put a system of equations inside boxes has +% hitherto been forced to use the features of \pkg{fancybox} or the \cmd{\boxed} command +% of \pkg{amsmath}. Both alternatives have serious limitations though. +% \pkg{fancybox} allows only \env{eqnarray}-style equations and at +% the end of the day they aren't all that pretty. Most mathematical +% typesetting in \LaTeX\ is done with the aid of \pkg{amsmath} +% anyway, but it only offers the single line quick-fix \cmd{\boxed}. +% What we really want is something that will enable us to do +% something along the likes of this: +% \begin{subequations}\label{eq:1} +% \begin{empheq}[boxtype=\fbox,Left= {\tilde{S}=1 \Rightarrow\empheqlbrace}] +% \begin{align} +% a&=\int_{-2}^3{t}b^t \, dt \quad\text{and} \label{eq:1a}\\ +% c&=d-a \label{eq:1b} +% \end{align} +% \end{empheq} +% \end{subequations} +% As you can see, \EQ\ can do all the tricks the \pkg{cases} package +% by Donald Arseneau can do and more. It even supports +% \env{subequations}---as shown in equations \eqref{eq:1a} and +% \eqref{eq:1b}---from \pkg{amsmath} without complaining. +% +% In order to combine the best of two worlds the \EQ\ package +% tries to take advantage of the widespread features of \pkg{amsmath}. +% As it should be well known if you read this, \pkg{amsmath} has +% amongst its arsenal of structures \env{align}, \env{gather}, \env{alignat} and \env{multline}. +% \EQ\ works with these as well as their starred +% variants. +% +% ``But what about \env{equation}?'' you say. \env{equation} is (in +% my opinion) merely a poor man's \env{gather}. If you really want +% to use \EQ's features on a one-liner (no pun intended) go with +% \env{gather}. Anyway the real goal of this package is to do nifty +% tricks with multi line equations \ldots +% +% +% \section{Examples} +% \changes{v0.7}{2003/05/11}{Added further examples and changed existing ones} +% Any options given to \EQ\ is passed on to \pkg{amsmath}, thus the +% line\par +% \cmd{\usepackage}\oarg{options}|{empheq07}|\\ +% will load \pkg{amsmath} with exactly those options. \EQ\ doesn't +% redefine anything so to use it in an existing document you need +% only replace \pkg{amsmath} with \EQ---no harm done. +% +% +% \EQ\ is \emph{really} easy to use; you simply put an \env{empheq} +% environment around your \pkg{amsmath} environment: +% \begin{verbatim} +% \begin{empheq} +% \begin{align} +% E&=mc^2 \\ +% Y&= \sum_{n=1}^\infty \frac{1}{n^2} +% \end{align} +% \end{empheq} +% \end{verbatim} +% \begin{empheq} +% \begin{align} +% E&=mc^2 \\ +% Y&= \sum_{n=1}^\infty \frac{1}{n^2} +% \end{align} +% \end{empheq} +% Impressed? No? Well then I guess it's about time I told you about +% the \emph{optional} argument of the \env{empheq} environment. It allows +% you control what material to put on either side of the math and +% the sort of box to go around it all. That means that we can say +% \begin{verbatim} +% \begin{empheq}[boxtype=\fbox] +% \begin{align} +% E&=mc^2 \\ +% Y&= \sum_{n=1}^\infty \frac{1}{n^2} +% \end{align} +% \end{empheq} +% \end{verbatim} +% to obtain the display +% \begin{empheq}[boxtype=\fbox] +% \begin{align} +% E&=mc^2 \\ +% Y&= \sum_{n=1}^\infty \frac{1}{n^2} +% \end{align} +% \end{empheq} +% This requires the use of the \pkg{keyval} package from the tools +% bundle, which is undoubtedly installed on your system. When using +% the \pkg{keyval} package there are a few things we need to keep in +% mind. In mathematical typesetting `|=|' and `|,|' are quite +% frequently used, thus requiring the user to enclose them in +% braces: +% \begin{verbatim} +% \begin{empheq}[boxtype=\fbox, +% Left={(a,b)=(c,i) \Rightarrow\empheqlbrace}] +% \begin{alignat}{2} +% (a,b)&= (\cos^a c, \tan^b i)&& \quad\text{for $i>1$}\\ +% (a,b)&= (\arccos x^a, \arctan i^b)&& \quad\text{for $i\leq1$} +% \end{alignat} +% \end{empheq} +% \end{verbatim} +% \begin{empheq}[boxtype=\fbox, +% Left={(a,b)=(c,i) \Rightarrow\empheqlbrace}] +% \begin{alignat}{2} +% (a,b)&= (\cos^a c, \tan^b i)&& \quad\text{for $i>1$}\\ +% (a,b)&= (\arccos c^a, \arctan i^b)&& \quad\text{for $i\leq1$} +% \end{alignat} +% \end{empheq} +% The same with \env{cases} from \pkg{amsmath} for comparison: +% \[ +% \boxed{(a,b)=(c,i) \Rightarrow +% \begin{cases} (a,b)= (\cos^a c, \tan^b i)& \text{for $i>1$}\\ +% (a,b)= (\arccos x^a, \arctan i^b)& \text{for $i\leq1$} +% \end{cases}} +% \] +% Notice that \env{cases} uses an array for the conditions, so you +% have to force \cmd{\displaystyle} yourself. This is not needed with +% \EQ\ as you're already using a \cmd{\displaystyle} environment such as +% \env{gather} etc. +% +% \changes{v0.6b}{2003/03/04}{Added example for changing margins inside the boxtype.} +% Observe what can be done if we replace +% |\fbox| with another framed box and add some space on all sides: +% \begin{verbatim} +% \definecolor{lightblue}{rgb}{.8, .8, 1} +% \begin{empheq}[boxtype={\setlength{\fboxsep}{10pt}% +% \colorbox{lightblue}}, +% Right={\empheqrbrace \beta}] +% . +% . +% . +% \end{empheq} +% \end{verbatim} +% \begin{empheq}[boxtype={\setlength{\fboxsep}{10pt}% +% \colorbox{lightblue}},Right={\empheqrbrace \beta}] +% \begin{align} +% a&=\int_{-2}^3{t}b^t \, dt \quad\text{and}\\ +% c&=d-a +% \end{align} +% \end{empheq} +% +% As a convenience for the user, it is also possible to declare +% delimiters with the commands +% \cmd{\DeclareRightDelimiter}\marg{delimiter} and its companion +% \cmd{\DeclareLeftDelimiter}\marg{delimiter}. For instance the commands +% \begin{quote} +% |\DeclareRightDelimiter{\rangle}| defines \cmd{\empheqrangle} +% \end{quote} +% and +% \begin{quote} +% |\DeclareLeftDelimiter{\langle}| defines \cmd{\empheqlangle}. +% \end{quote} +% The usage is simple. \DeclareRightDelimiter{\rangle} \DeclareLeftDelimiter{\langle} +% \begin{verbatim} +% \begin{empheq}[Right=\empheqrangle, +% Left=\empheqlangle] +% \begin{gather} +% a=b \\ +% c=d +% \end{gather} +% \end{empheq} +% \end{verbatim} +% \begin{empheq}[Right=\empheqrangle,Left=\empheqlangle] +% \begin{gather} +% a=b \\ +% c=d +% \end{gather} +% \end{empheq} +% \cmd{\DeclareRightDelimiter} and its companion have an optional +% argument which controls spacing (default is a negative thinspace), +% but beware: It will simply overwrite the original definition and +% it might not look all that pretty as the following example shows: +% \DeclareRightDelimiter[\>]{\rangle} +% \DeclareLeftDelimiter[\mkern-10mu]{\langle} +% \begin{verbatim} +% \DeclareRightDelimiter[\>]{\rangle} +% \DeclareLeftDelimiter[\mkern-10mu]{\langle} +% \end{verbatim} +% \begin{empheq}[Right=\empheqrangle,Left=\empheqlangle] +% \begin{gather} +% a=b \\ +% c=d +% \end{gather} +% \end{empheq} +% +% These examples will have given you a glimpse of the possibilities +% \EQ\ offers. In particular the commands \cmd{\empheqlbrace} and +% \cmd{\empheqrbrace} produce braces just tall enough to encompass +% the display. You can of course use \cmd{\big...} delimiters if you +% want. +% +% \ifBonusExample +% If you want you can even create your own box and use it with +% \env{empheq}. In the following silly example I have created +% \cmd{\ErrorBox} with \pkg{PSTricks} to achieve a disturbing +% effect: +% \makeatletter +% \newcommand{\ErrorBox}[1]{% +% \setlength{\@tempdima}{\heightof{#1}}% +% \addtolength{\@tempdima}{\depthof{#1}}% +% \setlength{\@tempdimb}{\widthof{#1}}% +% \psset{yunit=\@tempdima}% +% \psset{xunit=\@tempdimb}% +% \psframebox[fillstyle=vlines,linestyle=none,hatchsep=.2\@tempdimb,hatchcolor=red,hatchangle=-60]{% +% \rlap{\kern.5\@tempdimb\makebox[0pt]{{\Large\color{gray} \textbf{Error!}}}}#1}% +% } +% \makeatother +% \begin{empheq}[boxtype=\ErrorBox] +% \begin{align*} +% E&=mc^3 \\ +% F&=G\frac{m+M}{r^2} +% \end{align*} +% \end{empheq} +% Remember one thing when creating your own box: Make it +% symmetrical. +% \fi +% +% \section{Bugs and shortcomings} +% This package (\EQ) is not supported anymore. Try with the new +% version and see if it works; if not, then contact me. See how in +% the manual of \pkg{empheq}. +% +% \StopEventually{} +% \section{Implementation} +% \subsection{Strategy} +% +% Whenever \pkg{amsmath} is typesetting a display environment it +% actually does it twice; the first for the ``measuring'' phase and +% the second for the ``production'' phase. The \EQ\ package uses a +% similar approach: +% \begin{itemize} +% \item Collects the input in a token register for later use. +% \item Typesets the input in the background and checks certain values to determine the kind of math structure you just typed. +% \item Based on the given information, alterations are made to various lengths. +% \item Then the equations are typeset again and stored in a box +% for easy retrieval. +% \item Finally the saved box is put into a box of the user's liking. +% Any material to the right or left of the math structure (added with +% the |Left| and |Right| keys) are put into the box as well. +% \end{itemize} +% Assuming we have found out which \pkg{amsmath} structure the +% user typed, there are still a few things we need to sort out +% before we proceed. +% +% First of all the equation number should still be aligned with +% those of the ordinary math structures, which is a problem as soon +% as the additions we make to the left and the right +% differ---presumably they will. And when we are in \mode{fleqn} +% mode, we should make sure that the structure is shifted just +% enough to the right so that all equations still are right +% adjusted. Therefore we need to make clever changes to the +% line width to make sure the margins come out right. +% +% Then assuming we have overcome all of this there's still the final +% step: Placing the math structure in the appropriate box at the +% appropriate position. Once again we need to do some manipulation +% with spacing to make it just right. +% +% \subsection{Preliminary actions} +% +% To avoid clashes with other packages, all private commands will contain the sequence \verb|@emphEQ@|. +% +% We will need \pkg{amsmath} of course and it would be nice if \EQ\ +% would recognize all the \pkg{amsmath} options so we make that +% happen. To make sure the user has an updated system the newest +% release of \pkg{amsmath} is required. +% +% \pkg{calc} is used to increase readability of the code +% (thus making it \emph{far} easier to write too) and \pkg{keyval} +% is used for user friendliness. They should all be part of any +% \LaTeX\ system. +% \begin{macrocode} +%<*package> +\DeclareOption*{\PassOptionsToPackage{\CurrentOption}{amsmath}} +\ProcessOptions\relax +\RequirePackage{amsmath}[2000/07/18] +\RequirePackage{calc,keyval} +% \end{macrocode} +% \begin{macro}{\if@emphEQ@FLL}\begin{macro}{\if@emphEQ@FLR}\begin{macro}{\if@emphEQ@L}\begin{macro}{\if@emphEQ@R} +% There are four available layouts for mathematical displays: +% |[fleqn,leqno]| (FLL), |[fleqn,reqno]| (FLR), |[leqno]| (L) and |[reqno]| (R). We create four \TeX\ conditionals +% to make the algorithm easier to read as well as to speed up things a bit. +% \begin{macrocode} +\newif\if@emphEQ@FLL +\newif\if@emphEQ@FLR +\newif\if@emphEQ@L +\newif\if@emphEQ@R +% \end{macrocode} +%\end{macro}\end{macro}\end{macro}\end{macro} +% We then perform a simple test to determine the current mode. +% \begin{macrocode} +\if@fleqn + \iftagsleft@ + \@emphEQ@FLLtrue + \else + \@emphEQ@FLRtrue + \fi +\else + \iftagsleft@ + \@emphEQ@Ltrue + \else + \@emphEQ@Rtrue + \fi +\fi +% \end{macrocode} +% \begin{macro}{\if@emphEQ@gather}\begin{macro}{\if@emphEQ@align}\begin{macro}{\if@emphEQ@alignat} +% \begin{macro}{\if@emphEQ@multline}\begin{macro}{\if@emphEQ@NoNumEq} +% Since we're going to determinate which math structure the user has +% input, we create some more conditionals to improve speed and +% readability. Furthermore it will show crucial to know whether or +% not the equation counter has been stepped since \env{multline$*$} +% and \env{multline} don't have exactly the same structure. +% \begin{macrocode} +\newif\if@emphEQ@gather +\newif\if@emphEQ@align +\newif\if@emphEQ@alignat +\newif\if@emphEQ@multline +\newif\if@emphEQ@NoNumEq +% \end{macrocode} +% \end{macro}\end{macro}\end{macro}\end{macro}\end{macro} +% +% +% +% \begin{macro}{\@emphEQ@Box}\begin{macro}{\@emphEQ@BoxWidth} +% \begin{macro}{\@emphEQ@displaywidth}\begin{macro}{\@emphEQ@mathbody} +% We need a single box to hold the math structure, a length so we +% can remember the size of the displayed math for later use and a +% token register for the math environment. +% \begin{macrocode} +\newsavebox{\@emphEQ@Box} +\newlength{\@emphEQ@BoxWidth} +\newlength{\@emphEQ@displaywidth} +\newtoks\@emphEQ@mathbody +% \end{macrocode} +% \end{macro}\end{macro}\end{macro}\end{macro} +% \begin{macro}{\@emphEQ@Left}\begin{macro}{\@emphEQ@Right}\begin{macro}{\@emphEQ@lwd}\begin{macro}{\@emphEQ@rwd} +% Here are some vital parts: The additional informations the user +% want to display on either side of the math structure are saved by +% \cmd{\@emphEQ@Left} and \cmd{\@emphEQ@Right} and \cmd{\@emphEQ@lwd} and \cmd{\@emphEQ@rwd} +% measure the width of them for later use. +% \begin{macrocode} +\newcommand{\@emphEQ@Left}{} +\newcommand{\@emphEQ@Right}{} +\newlength{\@emphEQ@lwd} +\newlength{\@emphEQ@rwd} +% \end{macrocode} +% \end{macro}\end{macro}\end{macro}\end{macro} +% \begin{macro}{\@emphEQ@boxtype}\begin{macro}{\@emphEQ@boxtypelength} +% \begin{macro}{\@emphEQ@shadowbox}\begin{macro}{\if@emphEQ@shadowbox} +% To make sure spacing is right when putting the math structure into +% a box, we need to know what kind of box it is: The width is +% extremely important. Often we will have to subtract or add half of +% an empty (but \emph{not} zero-width) box' width to certain +% lengths. When using an \cmd{\fbox} or \cmd{\colorbox} this is just +% \cmd{\fboxrule}+\cmd{\fboxsep}, but when using say, +% \cmd{\doublebox} of \pkg{fancybox} fame the necessity arises. +% \pkg{fancybox} also defines \cmd{\shadowbox} which needs extra +% taking care of, since it's asymmetrical unlike most other framed +% boxes. +% +% Thus we test whether or not \pkg{fancybox} has been loaded at the +% beginning of the document. If it has, we don't lift a finger; if +% it hasn't, we let \cmd{\fbox} be an alias for \cmd{\shadowbox}. +% Then we create a private version of \cmd{\shadowbox} for +% testing purposes and a conditional for the algorithm. +% \begin{macrocode} +\newcommand{\@emphEQ@boxtype}{} +\newlength{\@emphEQ@boxtypelength} +\AtBeginDocument{% + \@ifpackageloaded{fancybox}{}{% + \let\shadowbox=\fbox}} +\newcommand{\@emphEQ@shadowbox}{\shadowbox} +\newif\if@emphEQ@shadowbox +% \end{macrocode} +% \end{macro}\end{macro}\end{macro}\end{macro} +% \begin{macro}{\@emphEQ@templength}\begin{macro}{@emphEQ@EqCtr} +% We are almost ready to go. We only need two temporary little +% helpers: one length and one counter. +% \begin{macrocode} +\newlength{\@emphEQ@templength} +\newcounter{@emphEQ@EqCtr} +% \end{macrocode} +% \end{macro}\end{macro} +% +% \subsubsection{Faraway, so close}\label{sec:CloseEnough} +% \begin{macro}{\@emphEQ@CloseEnough} +% \changes{v0.6}{2003/01/10}{Added a test for lengths being almost identical} +% When determining the display type we will occasionally have to check if an equation of the +% form +% \[ +% \cmd{\totwidth@}-\cmd{\tagshift@}=\cmd{\linewidth} +% \] +% is true. However small rounding errors \emph{can} occur in +% \env{alignat} so we would rather see if the equation +% \[ +% -\delta<\cmd{\totwidth@}-\cmd{\tagshift@}-\cmd{\linewidth}<\delta +% \] +% holds for some sufficiently small $\delta>\text{$0$ pt}$. I have used $\delta=\text{$5$ sp}$. +% \begin{macrocode} +\newcommand{\@emphEQ@CloseEnough}[4]{% + \setlength{\@tempdima}{#1-#2}% + \ifdim\@tempdima>-5sp + \ifdim\@tempdima<5sp + #3 + \else + #4 + \fi + \else + #4 + \fi +} +% \end{macrocode} +% \end{macro} +% +% \subsection{Saving the input} +% \begin{macro}{\@emphEQ@MainEnv} +% \changes{v0.7}{2003/05/11}{Added use of token register to remove the +% need for an extra \cmd{\write} and \pkg{verbatim}} +% \begin{macro}{\end@emphEQ@MainEnv} +% \begin{macro}{\@emphEQ@get@body}\begin{macro}{\@emphEQ@findend} +% \begin{macro}{\@emphEQ@EnvName} +% We start out by saving the input in the token register +% \cmd{\@emphEQ@mathbody}. The method is heavily inspired by +% \pkg{tabularx} \dots\@ No need to copy the words of David Carlisle here---his code will do! +% \begin{macrocode} +\def\@emphEQ@MainEnv{% + \edef\@emphEQ@EnvName{\@currenvir}% + {\ifnum0=`}\fi + \@emphEQ@mathbody{}\@emphEQ@get@body +} +\let\end@emphEQ@MainEnv\relax +\long\def\@emphEQ@get@body#1\end{% + \@emphEQ@mathbody\expandafter{\the\@emphEQ@mathbody #1}% + \@emphEQ@findend +} +\def\@emphEQ@findend#1{% + \def\@tempa{#1}% + \ifx\@tempa\@emphEQ@EnvName + \expandafter\@emphEQ@PostProcess + \else + \@emphEQ@mathbody\expandafter{\the\@emphEQ@mathbody\end{#1}}% + \expandafter\@emphEQ@get@body + \fi +} +\def\@emphEQ@EnvName{@emphEQ@MainEnv} +% \end{macrocode} +% \end{macro}\end{macro}\end{macro}\end{macro}\end{macro} +% \begin{macro}{@emphEQ@PostProcess} +% Now we can go on with the post processing, which is the real +% workhorse in this package. The first job is to test if we're +% using a \cmd{\shadowbox} and then we set some \pkg{amsmath} +% dimensions to zero---\pkg{amsmath} doesn't do this by itself, and +% for that we can be thankful. Otherwise you wouldn't be reading +% this now~;-) +% \begin{macrocode} +\newcommand*{\@emphEQ@PostProcess}{% + \ifx\@emphEQ@boxtype\@emphEQ@shadowbox + \@emphEQ@shadowboxtrue + \else + \@emphEQ@shadowboxfalse + \fi + \tagshift@=0pt \tagwidth@=0pt \totwidth@=0pt + \eqnshift@=0pt \alignsep@=0pt +% \end{macrocode} +% \subsection{The first pass} +% We then run the first pass to find out which environment we've +% got. However we have to store the equation counter because it is +% stepped in this pass, and we certainly don't want that to happen. +% As a side effect this will also tell us if the equations are +% numbered. +% +% If we are to put a brace to the left of the display, it would be +% rather pleasant to know just how high the structure is, since this +% will affect the height and more importantly the width the brace: +% we will need to know the \emph{exact} width of such material. +% Hence we put it in a box which is easy to measure and fiddle +% around with. To achieve this we put the contents of the token register +% \cmd{\@emphEQ@mathbody} in a \env{minipage} inside a \env{lrbox}. Alas, +% \env{lrbox} won't let us escape into display math mode, so we play +% a dirty trick on it and use a \env{minipage}, which will let us +% have our way with it. +% +% The \env{minipage} starts in horizontal mode and then goes +% straight to display math mode, thus adding some space before the +% display math. However there was nothing on the first line in the +% \env{minipage} thus leading \TeX\ to add a \cmd{\abovedisplayskip} +% before the display. We subtract this as fast as we can! +% Furthermore it showed in test runs, that an additional~1~pt had to +% be subtracted in the top---but not in the bottom. It has nothing +% to do with any of the standard page dimensions or parameters. +% Strange indeed. +% \begin{macrocode} + \setcounter{@emphEQ@EqCtr}{\value{equation}}% + \begin{lrbox}{\@emphEQ@Box}% + \begin{minipage}{\linewidth}% + \vskip-\abovedisplayskip\relax\vskip-1pt\relax + \the\@emphEQ@mathbody + \end{minipage}% + \end{lrbox}% +% \end{macrocode} +% We then look at the equation counter to see if we had any numbered +% equations and reset it if that was the case. If we used a +% \env{multline$*$} we can detect this by measuring |\tagwidth@|. +% \begin{macrocode} + \ifnum\value{equation}=\value{@emphEQ@EqCtr}% + \ifdim\tagwidth@>0pt + \else + \@emphEQ@NoNumEqtrue + \fi + \else + \setcounter{equation}{\value{@emphEQ@EqCtr}}% + \fi +% \end{macrocode} +% Now we can determine the various math environments. Firstly we +% measure an empty \cmd{\@emphEQ@boxtype}---we will need this +% information when the math structure is finally put into a box of +% this type, but we have to take it into account when calculating +% the allowable width of \env{multline} displays because we want to +% use the margins already set for this environment. +% \begin{macrocode} + \settowidth{\@emphEQ@boxtypelength}{\@emphEQ@boxtype{}}% +% \end{macrocode} +% The idea is that each of the \pkg{amsmath} multiple line +% environments can be singled out because it uses a certain +% dimension in a way none of the others use it. +% \begin{list}{}{} +% \item[\env{align}:] Uses \cmd{\alignsep@} and sets it to something +% positive. None of the others use it. +% \item[\env{multline}:] Doesn't use \cmd{\eqnshift@}. +% \item[\env{gather}:] Doesn't use \cmd{\tagshift@}. +% \item[\env{alignat}:] Can be determined because some dimensions +% will have special relations e.g., when in |[fleqn,reqno]| mode +% the equation +% \[ +% \cmd{\totwidth@}-\cmd{\tagshift@}=\cmd{\linewidth} +% \] +% holds\footnote{Well almost---they may be off by a few scaled points. +% See section~\ref{sec:CloseEnough} for further details.} +% and similarly for the other three display modes. See the +% code for these equations. +% \end{list} +% +% \subsubsection{\mode{[fleqn,leqno]}} +% ~ +% \begin{macrocode} + \if@emphEQ@FLL % fleqn and leqno + \ifdim\alignsep@>0pt % => align + \@emphEQ@aligntrue + \setlength{\@emphEQ@displaywidth}{\tagshift@-\@mathmargin}% + \else + \ifdim\eqnshift@=0pt % => multline %tagwidth@> + \@emphEQ@multlinetrue + \if@emphEQ@NoNumEq + \setlength{\@emphEQ@displaywidth}{% + \linewidth-\multlinegap-\@mathmargin + -\@emphEQ@boxtypelength}% + \else + \setlength{\@emphEQ@displaywidth}{% + \linewidth-\tagwidth@-\multlinegap + -\multlinetaggap-\@emphEQ@boxtypelength}% + \fi + \else + \ifdim\tagshift@=0pt % => gather + \@emphEQ@gathertrue + \setlength{\@emphEQ@displaywidth}{% + \totwidth@-\@mathmargin}% + \else + \ifdim\tagshift@=\totwidth@ % => alignat + \@emphEQ@alignattrue + \setlength{\@emphEQ@displaywidth}{% + \totwidth@-\@mathmargin}% + \else + %Nothing thus far... + \fi + \fi + \fi + \fi + \fi +% \end{macrocode} +% \subsubsection{\mode{[fleqn,reqno]}} +% ~ +% \begin{macrocode} + \if@emphEQ@FLR % fleqn and reqno + \ifdim\alignsep@>0pt % => align + \@emphEQ@aligntrue + \setlength{\@emphEQ@displaywidth}{% + \linewidth-\@mathmargin+\tagshift@}% + \else + \ifdim\eqnshift@=0pt % => multline + \@emphEQ@multlinetrue + \if@emphEQ@NoNumEq + \setlength{\@emphEQ@displaywidth}{% + \linewidth-\multlinegap-\@mathmargin + -\@emphEQ@boxtypelength}% + \else + \setlength{\@emphEQ@displaywidth}{% + \linewidth-\tagwidth@-\@mathmargin + -\multlinetaggap-\@emphEQ@boxtypelength}% + \fi + \else + \ifdim\tagshift@=0pt % => gather + \@emphEQ@gathertrue + \setlength{\@emphEQ@displaywidth}{% + \totwidth@-\@mathmargin}% + \else + \@emphEQ@CloseEnough{\totwidth@-\tagshift@}% + {\linewidth}% + {\@emphEQ@alignattrue + \setlength{\@emphEQ@displaywidth}% + {\totwidth@-\eqnshift@}}{}% + \fi + \fi + \fi + \fi +% \end{macrocode} +% \subsubsection{\mode{[reqno]}} +% ~ +% \begin{macrocode} + \if@emphEQ@R % reqno + \ifdim\alignsep@>0pt % => align + \@emphEQ@aligntrue + \setlength{\@emphEQ@displaywidth}{\totwidth@}% + \else + \ifdim\eqnshift@=0pt % => multline + \@emphEQ@multlinetrue + \if@emphEQ@NoNumEq + \setlength{\@emphEQ@displaywidth}{% + \linewidth-2\multlinegap + -\@emphEQ@boxtypelength}% + \else + \setlength{\@emphEQ@displaywidth}{% + \linewidth-\tagwidth@-\multlinegap + -\multlinetaggap-\@emphEQ@boxtypelength}% + \fi + \else + \ifdim\tagshift@=0pt % => gather + \@emphEQ@gathertrue + \setlength{\@emphEQ@displaywidth}{\totwidth@}% + \else + \@emphEQ@CloseEnough{\tagshift@}{-\eqnshift@}% + {\@emphEQ@alignattrue + \setlength{\@emphEQ@displaywidth}{\totwidth@}}{}% + \fi + \fi + \fi + \fi +% \end{macrocode} +% \subsubsection{\mode{[leqno]}} +% ~ +% \begin{macrocode} + \if@emphEQ@L % leqno + \ifdim\alignsep@>0pt % => align + \@emphEQ@aligntrue + \setlength{\@emphEQ@displaywidth}{\totwidth@}% + \else + \ifdim\eqnshift@=0pt % => multline + \@emphEQ@multlinetrue + \if@emphEQ@NoNumEq + \setlength{\@emphEQ@displaywidth}{% + \linewidth-2\multlinegap + -\@emphEQ@boxtypelength}% + \else + \setlength{\@emphEQ@displaywidth}{% + \linewidth-\tagwidth@-\multlinegap + -\multlinetaggap-\@emphEQ@boxtypelength}% + \fi + \else + \ifdim\tagshift@=0pt % => gather + \@emphEQ@gathertrue + \setlength{\@emphEQ@displaywidth}{\totwidth@}% + \else + \@emphEQ@CloseEnough{% + \linewidth-\eqnshift@}{\tagshift@}{% + \@emphEQ@alignattrue + \setlength{\@emphEQ@displaywidth}{\totwidth@}}% + {}% + \fi + \fi + \fi + \fi +% \end{macrocode} +% Phew! That was tedious, but necessary. I wish I could say it got +% better further down the road, but it doesn't. Now we can measure +% the width of the additional material on both sides of the math +% structure. We add braces here and there to avoid any +% \cmd{\thinmuskip}'s. +% \begin{macrocode} + \settowidth{\@emphEQ@lwd}{${\@emphEQ@Left}% + {\vphantom{\usebox{\@emphEQ@Box}}}$}% + \settowidth{\@emphEQ@rwd}{${\vphantom{\usebox{\@emphEQ@Box}}}% + {\@emphEQ@Right}$}% +% \end{macrocode} +% +% \subsection{The second pass} +% +% When we try to create an effect as in the preliminary example +% there are a few things we need to tell \LaTeX\ for the overall +% result to be acceptable. If the display math is centered, then the +% new one should also be centered. This means that when typesetting +% the math structure for the second time, we need to make +% adjustments to \cmd{\linewidth}, \cmd{\@mathmargin} etc.\ for the +% equation tag to be placed correctly. +% +% That process is extremely tedious, but there are only few +% shortcuts, so we just go through each of the four environments, check +% each of the four display modes and alter dimensions a we trudge +% along. First we check if we are trying to put something into an +% asymmetrical box and then make it symmetrical be removing the size +% of the shadow. +% \begin{macrocode} + \begin{lrbox}{\@emphEQ@Box}% + \if@emphEQ@shadowbox + \addtolength{\@emphEQ@boxtypelength}{-\shadowsize}% + \fi +% \end{macrocode} +% \subsubsection{\env{align}} +% ~ +% \begin{macrocode} + \if@emphEQ@align + \if@emphEQ@FLL + \begin{minipage}{\linewidth+\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}%% + \fi + \if@emphEQ@FLR + \begin{minipage}{\linewidth}% + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}%% + \fi + \if@emphEQ@L + \begin{minipage}{\linewidth+\@emphEQ@lwd-\@emphEQ@rwd}% + \fi + \if@emphEQ@R + \begin{minipage}{\linewidth-\@emphEQ@lwd+\@emphEQ@rwd}% + \fi + \fi +% \end{macrocode} +% \subsubsection{\env{gather}} +% ~ +% \begin{macrocode} + \if@emphEQ@gather + \if@emphEQ@FLL + \begin{minipage}{\linewidth+\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}%% + \fi + \if@emphEQ@FLR + \begin{minipage}{\linewidth}% + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}%% + \fi + \if@emphEQ@R + \setlength{\@emphEQ@templength}{\linewidth-\totwidth@ + -\eqnshift@}% + \begin{minipage}{\linewidth-\@emphEQ@lwd+\@emphEQ@rwd + +\@emphEQ@templength-\eqnshift@}% + \fi + \if@emphEQ@L + \setlength{\@emphEQ@templength}{\linewidth-\totwidth@ + -\eqnshift@}% + \begin{minipage}{\linewidth+\@emphEQ@lwd-\@emphEQ@rwd + -\@emphEQ@templength+\eqnshift@}% + \fi + \fi +% \end{macrocode} +% \subsubsection{\env{alignat}} +% ~ +% \begin{macrocode} + \if@emphEQ@alignat + \if@emphEQ@FLL + \begin{minipage}{\linewidth+\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}%% + \fi + \if@emphEQ@FLR + \begin{minipage}{\linewidth}% + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}%% + \fi + \if@emphEQ@L + \begin{minipage}{\linewidth+\@emphEQ@lwd-\@emphEQ@rwd}% + \fi + \if@emphEQ@R + \begin{minipage}{\linewidth-\@emphEQ@lwd+\@emphEQ@rwd}% + \fi + \fi +% \end{macrocode} +% \subsubsection{\env{multline}} +% ~ +% \begin{macrocode} + \if@emphEQ@multline + \if@emphEQ@FLL + \begin{minipage}{\linewidth}% + \if@emphEQ@NoNumEq + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\@mathmargin}{\shadowsize} + \fi% + \else + \addtolength{\multlinetaggap}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\multlinegap}{\shadowsize}% + \fi + \fi + \addtolength{\multlinegap}{\@emphEQ@rwd + +.5\@emphEQ@boxtypelength}% + \fi + \if@emphEQ@FLR + \begin{minipage}{\linewidth}% + \if@emphEQ@NoNumEq + \addtolength{\multlinegap}{\@emphEQ@rwd + +.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\multlinegap}{\shadowsize}% + \fi + \else + \addtolength{\multlinetaggap}{\@emphEQ@rwd + +.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\multlinetaggap}{\shadowsize}% + \fi + \fi + \addtolength{\@mathmargin}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \fi + \if@emphEQ@L + \begin{minipage}{\linewidth}% + \if@emphEQ@NoNumEq + \addtolength{\multlinegap}{.5\@emphEQ@rwd + +.5\@emphEQ@lwd+.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\multlinegap}{.5\shadowsize}% + \fi + \else + \addtolength{\multlinetaggap}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \addtolength{\multlinegap}{\@emphEQ@rwd + +.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\multlinegap}{\shadowsize}% + \fi + \fi + \fi + \if@emphEQ@R + \begin{minipage}{\linewidth}% + \if@emphEQ@NoNumEq + \addtolength{\multlinegap}{.5\@emphEQ@rwd + +.5\@emphEQ@lwd+.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\multlinegap}{.5\shadowsize} + \fi + \else + \addtolength{\multlinetaggap}{\@emphEQ@rwd + +.5\@emphEQ@boxtypelength}% + \addtolength{\multlinegap}{\@emphEQ@lwd + +.5\@emphEQ@boxtypelength}% + \if@emphEQ@shadowbox + \addtolength{\multlinetaggap}{\shadowsize} + \fi + \fi + \fi + \fi +% \end{macrocode} +% Finally we get to typeset the contents of \cmd{\@emphEQ@mathbody} for +% the second time\ldots +% \begin{macrocode} + \vskip-\abovedisplayskip\relax\vskip-1pt\relax + \the\@emphEQ@mathbody + \end{minipage}% + \end{lrbox}% +% \end{macrocode} +% +% \subsection{Putting it into the box} +% +% Because we were clever to start with---by measuring the width of +% the display math and storing it in +% \cmd{\@emphEQ@displaywidth}---we can now put it into a box of +% width +% \cmd{\@emphEQ@displaywidth}+\cmd{\@emphEQ@rwd}+\cmd{\@emphEQ@lwd}. +% This doesn't apply to \env{multline} though: it has to be set in a +% box of width \cmd{\@emphEQ@displaywidth}. +% \begin{macrocode} +\setlength{\@emphEQ@BoxWidth}{\@emphEQ@displaywidth+\@emphEQ@rwd + +\@emphEQ@lwd}% +% \end{macrocode} +% \subsubsection{\env{align}} +% ~ +% \begin{macrocode} +\if@emphEQ@align + \if@emphEQ@FLL + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength% + \kern-\@mathmargin + \kern-\@emphEQ@lwd + \usebox{\@emphEQ@Box}% + \kern-\@emphEQ@displaywidth + \kern-\@emphEQ@rwd + \kern-\@emphEQ@lwd + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@FLR + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength% + \kern-\@mathmargin + \kern-\@emphEQ@lwd + \usebox{\@emphEQ@Box}% + \kern-\alignsep@ + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@L + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][c]{% + %\kern\eqnshift@ + %\kern-\alignsep@ + $\@emphEQ@Left$% + \kern-\eqnshift@ + %\kern-\alignsep@ + \usebox{\@emphEQ@Box}% + %\kern-\eqnshift@ + \kern-\alignsep@ + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@R + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][c]{% + $\@emphEQ@Left$% + \kern-\eqnshift@ + \usebox{\@emphEQ@Box}% + \kern-\eqnshift@ + $\@emphEQ@Right$}}% + \fi +\fi +% \end{macrocode} +% \subsubsection{\env{alignat}} +% ~ +% \begin{macrocode} +\if@emphEQ@alignat + \if@emphEQ@FLL + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \kern-\@mathmargin + \kern-\@emphEQ@lwd + \usebox{\@emphEQ@Box}% + \kern\@mathmargin + \kern\@emphEQ@displaywidth + \kern-\linewidth + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@FLR + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \kern-\@mathmargin + \kern-\@emphEQ@lwd + \usebox{\@emphEQ@Box}% + \kern\@mathmargin + \kern\@emphEQ@displaywidth + \kern-\linewidth + \kern\@emphEQ@lwd + \kern.5\@emphEQ@boxtypelength + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@L + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][c]{% + $\@emphEQ@Left$% + \kern-\eqnshift@ + \usebox{\@emphEQ@Box}% + \kern-\eqnshift@ + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@R + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][c]{% + $\@emphEQ@Left$% + \kern-\eqnshift@ + \usebox{\@emphEQ@Box}% + \kern-\eqnshift@ + $\@emphEQ@Right$}}% + \fi +\fi +% \end{macrocode} +% \subsubsection{\env{gather}} +% ~ +% \begin{macrocode} +\if@emphEQ@gather + \if@emphEQ@FLL + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \kern-\@mathmargin + \kern-\@emphEQ@lwd + \usebox{\@emphEQ@Box}% + \kern-\linewidth + \kern\@mathmargin + \kern\@emphEQ@displaywidth + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@FLR + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize + \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \kern-\@mathmargin + \kern-\@emphEQ@lwd + \usebox{\@emphEQ@Box}% + \kern-\linewidth + \kern.5\@emphEQ@boxtypelength + \kern\@mathmargin + \kern\@emphEQ@displaywidth + \kern\@emphEQ@lwd + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@L + \setlength{\tagwidth@}{\eqnshift@+\@emphEQ@rwd}% + \setlength{\@emphEQ@templength}{\linewidth-\totwidth@ + -\eqnshift@}% + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][c]{% + \ifdim\@emphEQ@templength<\tagwidth@ + \setlength{\tagwidth@}{\@emphEQ@templength + +\@emphEQ@lwd}% + \ifdim\tagwidth@<\eqnshift@ + \kern-\@emphEQ@templength + \kern\eqnshift@ + \fi + \else + \kern-\@emphEQ@lwd + \kern\@emphEQ@rwd + \kern-\@emphEQ@templength + \kern\eqnshift@ + \fi + $\@emphEQ@Left$% + \kern-\eqnshift@ + \usebox{\@emphEQ@Box}% + %\kern-\eqnshift@ + \kern-\@emphEQ@lwd + \kern\@emphEQ@rwd + \kern-\@emphEQ@templength + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@R + \setlength{\tagwidth@}{\eqnshift@+\@emphEQ@rwd}% + \setlength{\@emphEQ@templength}{\linewidth-\totwidth@ + -\eqnshift@}% + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@BoxWidth][c]{% + \kern-\@emphEQ@lwd + \kern\@emphEQ@rwd + \kern\@emphEQ@templength + \kern-\eqnshift@ + $\@emphEQ@Left$% + \ifdim\@emphEQ@templength>\tagwidth@ + \kern-\eqnshift@ + \else + \kern\@emphEQ@lwd + \kern-\@emphEQ@rwd + \kern-\@emphEQ@templength + \fi + \usebox{\@emphEQ@Box}% + \kern-\eqnshift@ + $\@emphEQ@Right$}}% + \fi +\fi +% \end{macrocode} +% \subsubsection{\env{multline}} +% +% \env{multline} is somewhat more difficult because \env{multline$*$} +% differs on several accounts. Thus we make use of our little test +% to see if the math structure was numbered to begin with +% (\verb|\if@emphEQ@NoNumEq|). +% \begin{macrocode} +\if@emphEQ@multline + \if@emphEQ@FLL + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@displaywidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \kern-\@emphEQ@lwd + \if@emphEQ@NoNumEq + \if@emphEQ@shadowbox \kern-\shadowsize \fi + \kern-\@mathmargin + \else + \kern-\tagwidth@ + \kern-\multlinetaggap + \fi + \usebox{\@emphEQ@Box}% + \kern-\@emphEQ@boxtypelength + \if@emphEQ@NoNumEq + \kern-\multlinegap + \else + \kern\multlinegap + \fi + \kern-\@emphEQ@rwd + \kern-\@emphEQ@lwd + \kern-\@mathmargin + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@FLR + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@displaywidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \kern-\@emphEQ@lwd + \kern-\@mathmargin + \usebox{\@emphEQ@Box}% + \kern-\@emphEQ@boxtypelength + \kern-\@emphEQ@rwd + \kern-\@emphEQ@lwd + \if@emphEQ@NoNumEq + \kern-\multlinegap + \else + \kern-\multlinetaggap + \fi + \kern-\@mathmargin + \kern-\tagwidth@ + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@L + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@displaywidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \kern-\@emphEQ@lwd + \if@emphEQ@NoNumEq + \kern-\multlinegap + \kern.5\@emphEQ@lwd + \kern-.5\@emphEQ@rwd + \if@emphEQ@shadowbox \kern-.5\shadowsize \fi + \else + \kern-\multlinetaggap + \kern-\tagwidth@ + \fi + \usebox{\@emphEQ@Box}% + \kern-.5\@emphEQ@boxtypelength + \if@emphEQ@NoNumEq + \kern.5\@emphEQ@rwd + \kern-.5\@emphEQ@lwd + \fi + \kern-\@emphEQ@rwd + \kern-\multlinegap + $\@emphEQ@Right$}}% + \fi + \if@emphEQ@R + \savebox{\@emphEQ@Box}{\makebox[\@emphEQ@displaywidth][l]{% + \if@emphEQ@shadowbox \kern.5\shadowsize \fi + $\@emphEQ@Left$% + \kern-.5\@emphEQ@boxtypelength + \if@emphEQ@NoNumEq + \if@emphEQ@shadowbox \kern-.5\shadowsize \fi + \kern-.5\@emphEQ@rwd + \kern.5\@emphEQ@lwd + \fi + \kern-\@emphEQ@lwd + \kern-\multlinegap + \usebox{\@emphEQ@Box}% + \kern-.5\@emphEQ@boxtypelength + \kern-\@emphEQ@rwd + \if@emphEQ@NoNumEq + \kern-\multlinegap + \kern-.5\@emphEQ@lwd + \kern.5\@emphEQ@rwd + \else + \kern-\multlinetaggap + \fi + \kern-\tagwidth@ + $\@emphEQ@Right$}}% + \fi +\fi +% \end{macrocode} +% +% \subsubsection{The final step} +% +% At last here comes the good part! We are now ready to place the +% box containing all of our math material. If we have used a +% \env{multline} we have to do a few kerning tricks but at least we +% would seem to know the drill by now\ldots To make sure vertical +% spacing is ok, we put it all into a simple math environment +% \verb|\[...\]|. +% \begin{macrocode} +\[ + \if@emphEQ@align + \if@emphEQ@L + \kern-\alignsep@ + \kern\eqnshift@ + \fi + \fi + \if@emphEQ@gather + \if@emphEQ@L + \kern-\@emphEQ@templength + \kern\eqnshift@ + \kern\@emphEQ@rwd + \kern-\@emphEQ@lwd + \fi + \if@emphEQ@R + \setlength{\tagwidth@}{\eqnshift@+\@emphEQ@rwd}% + \ifdim\@emphEQ@templength>\tagwidth@ + \kern-\@emphEQ@templength + \kern\eqnshift@ + \kern\@emphEQ@lwd + \else + \kern\@emphEQ@templength + \kern-\eqnshift@ + \kern\@emphEQ@rwd + \kern-\@emphEQ@lwd + \fi + \fi + \fi + \if@emphEQ@multline + \if@emphEQ@NoNumEq + % naught + \else + \if@emphEQ@FLL + \kern-\@mathmargin + \kern\tagwidth@ + \kern\multlinetaggap + \fi + \if@emphEQ@L + \kern\tagwidth@ + \kern\multlinetaggap + \kern-\multlinegap + \fi + \if@emphEQ@R + \kern-\tagwidth@ + \kern-\multlinetaggap + \kern\multlinegap + \fi + \fi + \else +% \end{macrocode} +% If we are using a \cmd{\shadowbox} in centered display mode, I +% would rather that the shadowsize is ignored when placing the box. +% Reason: I think it looks better. Judge for yourself: +% \begin{gather} +% a=b\\ +% \Phi(x)=\int_{-\infty}^x e^{-t^2/2}\, dt +% \end{gather} +% +% \begin{empheq}[boxtype=\shadowbox] +% \begin{gather} +% a=b\\ +% \Phi(x)=\int_{-\infty}^x e^{-t^2/2}\, dt +% \end{gather} +% \end{empheq} +% \begin{macrocode} + \if@emphEQ@shadowbox + \if@emphEQ@R + \kern\shadowsize + \fi + \if@emphEQ@L + \kern\shadowsize + \fi + \fi + \fi + \@emphEQ@boxtype{\usebox{\@emphEQ@Box}}% +% \end{macrocode} +% After all is done, we empty out the added material and the +% boxtype. +% \begin{macrocode} + \gdef\@emphEQ@Left{}\gdef\@emphEQ@Right{}% + \gdef\@emphEQ@boxtype{}% + \]% + \ifnum0=`{\fi}% + \expandafter\end\expandafter{\@emphEQ@EnvName}% +} +% \end{macrocode} +% +% \subsection{Going public\ldots} +% \begin{macro}{boxtype}\begin{macro}{Left}\begin{macro}{Right}\begin{macro}{empheq} +% In order to simplify the user interface, we make use of +% \pkg{keyval}. We define three keys to be used along with a more +% accessible version of \env{@emphEQ@MainEnv}. +% \changes{v0.7}{2003/05/11}{Changed the user interface slightly} +% \begin{macrocode} +\define@key{empheq}{boxtype}{\renewcommand\@emphEQ@boxtype{#1}} +\define@key{empheq}{Left}{\def\@emphEQ@Left{#1}} +\define@key{empheq}{Right}{\def\@emphEQ@Right{#1}} +\newenvironment{empheq}[1][]{\setkeys{empheq}{#1}\@emphEQ@MainEnv}% + {\end@emphEQ@MainEnv\ignorespacesafterend}% +% \end{macrocode} +% \end{macro}\end{macro}\end{macro}\end{macro} +% \begin{macro}{\DeclareLeftDelimiter} +% \changes{v0.7}{2003/05/11}{Added delimiter interface} +% \begin{macro}{\DeclareRightDelimiter} +% \changes{v0.7}{2003/05/11}{Added delimiter interface} +% It might come in handy to have delimiters of the appropriate size +% available to cover the math display as in \eqref{eq:1}. Therefore +% we define two commands that will create such delimiters once and +% for all. +% Use this as an inspiration for further kinds of delimiters. +% \begin{macrocode} +\newcommand{\DeclareLeftDelimiter}[2][\!]{% + \@namedef{empheq\expandafter\@gobble\string#2}{ + \left#2 + \vphantom{\usebox{\@emphEQ@Box}}% + \right.#1}} +\newcommand{\DeclareRightDelimiter}[2][\!]{% + \@namedef{empheq\expandafter\@gobble\string#2}{% + #1\left. + \vphantom{\usebox{\@emphEQ@Box}}% + \right#2}}% +\DeclareRightDelimiter{\rbrace} +\DeclareLeftDelimiter{\lbrace} +%</package> +% \end{macrocode} +% \end{macro}\end{macro}\end{macro} +% \Finale +\endinput |