new latex/metapost package gmp (10mar11)

git-svn-id: svn://tug.org/texlive/trunk@21691 c570f23f-e606-0410-a88d-b1316a301751

2 files changed, 2410 insertions, 0 deletions

diff --git a/Master/texmf-dist/source/latex/gmp/gmp.dtx b/Master/texmf-dist/source/latex/gmp/gmp.dtx
new file mode 100644
index 00000000000..457f80450c8
--- /dev/null
+++ b/Master/texmf-dist/source/latex/gmp/gmp.dtx
@@ -0,0 +1,2339 @@
+% \iffalse meta-comment
+%
+% Copyright (C) 2011 by Enrico Gregorio 
+% <Enrico dot Gregorio at univr dot it>
+% -------------------------------------------------------
+% 
+% This work may be distributed and/or modified under the
+% conditions of the LaTeX Project Public License, either
+% version 1.3c 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 2005/12/01 or later.
+%
+% This work has the LPPL maintenance status `maintained'.
+% 
+% The Current Maintainer of this work is Enrico Gregorio.
+%
+% This work consists of the files
+%   gmp.dtx 
+%   gmp.ins
+% and the derived file gmp.sty.
+%
+% \fi
+%
+% \iffalse
+%<*driver>
+\ProvidesFile{gmp.dtx}
+%</driver>
+%<package>\NeedsTeXFormat{LaTeX2e}[2008/04/05]
+%<package>\ProvidesPackage{gmp}
+%<*package>
+    [2011/03/10 v1.0 Integrate MetaPost with LaTeX (EG)]
+%</package>
+%
+%<*driver>
+\documentclass{ltxdoc}
+\usepackage[T1]{fontenc}
+\usepackage[latin1]{inputenc}
+\usepackage[shellescape,tex]{gmp}
+\usepackage{url,float,microtype}
+\usepackage{metalogo,mflogo,color}
+\floatstyle{ruled}
+\restylefloat{figure}
+\restylefloat{table}
+
+% \newenvironment{averbatim}{\verbatim}{\endverbatim}
+\newenvironment{annotation}
+  {\par\addvspace{\medskipamount}\footnotesize}
+  {\par\addvspace{\medskipamount}}
+
+\newcommand{\cmdname}[1]{\texttt{\char`\\#1}}
+\renewcommand{\meta}[1]{$\langle$\textnormal{\itshape#1\/}$\rangle$}
+\renewcommand{\marg}[1]{\texttt{\char`\{#1\char`\}}}
+\renewcommand{\oarg}[1]{\texttt{[#1]}}
+
+\newcommand{\scratchcount}[1]{%
+\begin{mpost}
+n:=#1;
+height := 3/5\mpdim{\baselineskip} ; 
+span := 1/3 * height ; 
+drift := 1/10 * height ; 
+pickup pencircle scaled (1/12 * height) ; 
+def d = (uniformdeviate drift) enddef ; 
+for i := 1 upto n : 
+  draw
+    if (i mod 5)=0 : ((-d-4.5span,d)--(+d-0.5span,height-d))
+    else : ((-d,+d)--(+d,height-d)) fi
+    shifted (span*i,d-drift) ; 
+endfor; 
+picture cp ; 
+cp := currentpicture ; % for readability 
+setbounds currentpicture to
+  (llcorner cp shifted (0,-ypart llcorner cp) --
+   lrcorner cp shifted (0,-ypart lrcorner cp) --
+   urcorner cp -- ulcorner cp -- cycle) ;
+\end{mpost}}
+\makeatletter
+\newenvironment{scratchenum}{\begin{enumerate}%
+\@namedef{label\@enumctr}{\scratchcount{\arabic{\@enumctr}}}%
+}{\end{enumerate}}
+\makeatother
+
+\newcommand\VCEN[1]{$\vcenter{\hbox{#1}}$}
+\newcommand\lista[2][black]{%
+\VCEN{%
+\begin{mpost}[
+%mpcommands={n:=#3;color fuzzy_color ; fuzzy_color:=#1 ;},
+mpmem=metafun]
+n:=#2 ; color fuzzy_color ; fuzzy_color:=#1 ;
+
+height := 5pt ;
+span := 1/3 * height ; 
+drift := 1/10 * height ; 
+hsize := .7\mpdim{\linewidth} ;
+vstep := 10pt ; 
+xmax := hsize div 5span ;
+
+pickup pencircle scaled (1/12 * height) ; 
+def d = (uniformdeviate drift) enddef ; 
+for i := 1 upto n : 
+  xpos := ((i-1) mod (5*xmax))*span ;
+  ypos := ((i-1) div (5*xmax))*vstep ;
+  draw
+    if (i mod 5)=0 : ((-d-4.5span,d)--(+d-0.5span,height-d))
+    else : ((-d,+d)--(+d,height-d)) fi
+    shifted (xpos,-ypos+d-drift) withcolor fuzzy_color ; 
+endfor; 
+
+picture cp ; 
+cp := currentpicture ; % for readability 
+if (ypart ulcorner cp - ypart llcorner cp) <= vstep :
+setbounds currentpicture to
+  (llcorner cp shifted (0,-ypart llcorner cp) --
+   lrcorner cp shifted (0,-ypart lrcorner cp) --
+   urcorner cp -- ulcorner cp -- cycle) ;
+fi
+\end{mpost}}%
+}
+
+\newsavebox{\tacochapterbox}
+\newcommand{\tacochapterhead}[1]{%
+  \sbox\tacochapterbox{\Large\bfseries #1}%
+  {\ooalign{%
+     \MPclipOne{\mpdim{\wd\tacochapterbox+6pc}}
+               {\mpdim{\ht\tacochapterbox+3pc}}
+               {8}
+               {(.7,.7,.7)}
+               {red}
+     \cr
+     \hfill\raisebox{\dimexpr.5\ht\tacochapterbox+1.5pc\relax}
+       {\box\tacochapterbox}\hfill}}}
+
+\def\MPclipOne#1#2#3#4#5{\begin{mpost}
+      w := #1;  width  := 100;  wfactor := w/width;
+      h := #2;  height := 100;  hfactor := h/height;
+      color lightred;  lightred  := (.90,.50,.50);
+      color lightgray; lightgray := (.95,.95,.95);
+      color gray;      gray      := (.50,.50,.50);
+      def random_delta (expr d) =
+        d-(uniformdeviate 2d)
+      enddef;
+      z1 = (0,height);
+      z2 = (0,0);
+      z3 = (width,0);
+      z4 = (width,height);
+      z5 = (width+random_delta(.2width),height+random_delta(.2height));
+      z6 = (.5width+random_delta(.1width),height+random_delta(.1height));
+      pickup pencircle
+        xscaled (#3/wfactor)
+        yscaled (#3/(2*hfactor))
+        rotated 30;
+      draw z5..z1..z2..z3..z4..z6 withcolor #4;
+      pickup pencircle
+        xscaled (#3/wfactor)
+        yscaled (#3/hfactor);
+      draw z1 withcolor #5;
+      draw z2 withcolor #5;
+      draw z3 withcolor #5;
+      draw z4 withcolor #5;
+      draw z5 withcolor #5;
+      draw z6 withcolor #5;
+      newwidth  := (xpart (urcorner currentpicture)) -
+                   (xpart (llcorner currentpicture));
+      newheight := (ypart (urcorner currentpicture)) -
+                   (ypart (llcorner currentpicture));
+      currentpicture := currentpicture
+       xscaled (w/newwidth) yscaled (h/newheight);
+    \end{mpost}}
+
+\newcommand{\squares}[2][black]{%
+  \begin{mpost}
+  boolean timetofillbox;
+  sfactor:=.95;
+  path p,q; u:=\mpdim{#2\textwidth}/2;
+  p := (u,u) -- (-u,u) -- (-u,-u) -- (u,-u) -- cycle;
+  theta := 0; dtheta := .005;
+  forever:
+    theta := theta+dtheta;
+    q := p scaled sfactor rotated theta;
+    exitif ypart(point 0 of q) > u;
+  endfor;
+  fill p withrgbcolor #1; timetofillbox:=false;
+  for i:=1 upto 51:
+    p := p scaled sfactor rotated theta;
+    if timetofillbox:
+      fill p withrgbcolor #1; timetofillbox:=false;
+    else:
+      fill p withrgbcolor white-#1; timetofillbox:=true;
+    fi
+  endfor
+  \end{mpost}}
+
+\urldef\messageurl\url
+  {http://groups.google.com/group/comp.text.tex/browse_frm/thread/516fb024bb83bcda}
+
+\setcounter{secnumdepth}{1}
+
+\EnableCrossrefs         
+\CodelineIndex
+\RecordChanges
+\begin{document}
+  \DocInput{gmp.dtx}
+  \PrintChanges
+  \PrintIndex
+\end{document}
+%</driver>
+% \fi
+%
+% \CheckSum{698}
+%
+% \CharacterTable
+%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
+%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
+%   Digits        \0\1\2\3\4\5\6\7\8\9
+%   Exclamation   \!     Double quote  \"     Hash (number) \#
+%   Dollar        \$     Percent       \%     Ampersand     \&
+%   Acute accent  \'     Left paren    \(     Right paren   \)
+%   Asterisk      \*     Plus          \+     Comma         \,
+%   Minus         \-     Point         \.     Solidus       \/
+%   Colon         \:     Semicolon     \;     Less than     \<
+%   Equals        \=     Greater than  \>     Question mark \?
+%   Commercial at \@     Left bracket  \[     Backslash     \\
+%   Right bracket \]     Circumflex    \^     Underscore    \_
+%   Grave accent  \`     Left brace    \{     Vertical bar  \|
+%   Right brace   \}     Tilde         \~}
+%
+%
+% \changes{v1.0}{2011/03/10}{Initial version}
+%
+% \GetFileInfo{gmp.dtx}
+%
+% \DoNotIndex{\newcommand,\newenvironment,\!,\",\%,\',\:,\;,\=,\?}
+% \DoNotIndex{\@gobbletwo,\@ifundefined,\@makeother,\@nameuse,\@ne}
+% \DoNotIndex{\@onlypreamble,\@temp,\^,\`,\|,\~,\active,\advance,\@nil}
+% \DoNotIndex{\begin,\begingroup,\bgroup,\catcode,\chardef,\closeout}
+% \DoNotIndex{\color,\count@,\csname,\def,\define@key,\dimexpr,\@gobble}
+% \DoNotIndex{\do,\documentclass,\edef,\egroup,\else,\empty,\end,}
+% \DoNotIndex{\endcsname,\endgroup,\endinput,\expandafter,\fbox,\fi}
+% \DoNotIndex{\gdef,\global,\ifdefined,\IfFileExists,\ifnum,\ifx}
+% \DoNotIndex{\immediate,\jobname,\label,\lccode,\let,\long,\loop}
+% \DoNotIndex{\lowercase,\m@ne,\message,\MessageBreak,\newcounter}
+% \DoNotIndex{\newif,\newlinechar,\newtoks,\noexpand,\number}
+% \DoNotIndex{\PackageError,\PackageWarning,\PackageWarningNoLine}
+% \DoNotIndex{\par,\refstepcounter,\relax,\repeat,\RequirePackage}
+% \DoNotIndex{\space,\string,\the,\toks@,\usepackage,\x,\xdef,\z@}
+% 
+%
+% \title{The \textsf{gmp} package\thanks{This document
+%   corresponds to \textsf{gmp}~\fileversion, dated \filedate.}}
+% \author{Enrico Gregorio \\ \texttt{enrico DOT gregorio AT univr DOT it}}
+%
+% \maketitle
+%
+% \begin{center}
+% \tacochapterhead{Introduction}
+% \end{center}
+%
+% Con\TeX{}t is far more superior to \LaTeX{} in its integration of
+% \MP{}.  On the other hand, few people are going to do the big jump
+% towards Con\TeX{}t, especially if they have to use maths in their
+% documents.
+%
+% Nonetheless, sometimes a better integration between \LaTeX{} and
+% \MP{} would be welcome.  One great package is \textsf{mfpic}, but
+% its philosophy is different: it defines a set of \TeX{} macros which
+% are afterwards interpreted as \MP{}. It suffers a bit from its 
+% \MF{} origin: the user has to pass the dimensions of the created 
+% figure in advance, while \MP{} is able to figure them out by itself.
+%
+% A very recent package does similar things as \textsf{gmp}, Vafa
+% Khalighi's \mbox{\textsf{mpgraphics}}, from which I learned to add
+% the \texttt{runs} and \texttt{clean} keys. However also Vafa's
+% package can't pass parameters to the \MP{} pictures at run time.
+% I~have to thank Vafa Khalighi because his \textsf{mpgraphics}
+% package helped me to straighten some roughness from the preliminary
+% version of this package.  Another package is oriented to this
+% purpose, \textsf{emp} by Thorsten Ohl, but it has not been updated
+% since 1997.
+%
+% What I wanted was a package which could do \emph{automatically} the
+% compilation of \MP{} output and, moreover, could pass parameters to
+% \MP{}.  Wouldn't it be nice being able to define a graphic object in
+% terms of the current text width?  Or of the current baseline skip?
+% Or of some user defined parameter?  A ``reusable'' object which can
+% change depending on current conditions? This package is an answer;
+% it runs under \LaTeX{}, \textsc{pdf}\LaTeX{} and
+% \XeLaTeX{}.\footnote{It runs even under Lua\LaTeX{}, I'd say, but in
+% this case it doesn't exploit the possibility of a direct call to the
+% \MP{} library.}
+%
+% This has some consequences; for example, \MP{} labels will usually go
+% inside
+%\begin{verbatim}
+%\btex ... etex
+%\end{verbatim}
+% instead of the normal \verb|btex ... etex|. Later examples will show
+% this is an enrichment, rather than a limitation.
+%
+% \begin{mpost}[name=swelled]
+% breadth=.667\mpdim{\linewidth};
+% height=2pt;
+% x1=0;
+% x2=x6=.333x4;x5=x3=.667x4;
+% x4=breadth;
+% y1=y4=height/2;
+% y2=y3=height;
+% y5=y6=0;
+% fill z1--z2--z3--z4--z5--z6--cycle;
+% \end{mpost}
+%
+% Consider a swelled rule: we want its width to be two thirds of the
+% line width.  But, of course, we should not simply scale it when the
+% line width changes. Here is an example; the swelled rule for the
+% current line width:
+% \begin{center}
+% \usempost{swelled}
+% \end{center}
+% We follow it with a scaled version corresponding to half line width
+% (on the left) and a true swelled rule constructed for a halved line 
+% width:
+% \begin{center}
+% % \scalebox{.5}[1]{\usempost{swelled}}\qquad
+% \usempost[scale=.5]{swelled}\qquad
+% \begin{mpost}
+% breadth=.667\mpdim{\linewidth}/2;
+% height=2pt;
+% x1=0;
+% x2=x6=.333x4;x5=x3=.667x4;
+% x4=breadth;
+% y1=y4=height/2;
+% y2=y3=height;
+% y5=y6=0;
+% fill z1--z2--z3--z4--z5--z6--cycle;
+% \end{mpost}
+% \end{center}
+%
+% The difference is clear, but I must admit to have cheated: in this
+% case it would be sufficient to scale the swelled rule only in the
+% horizontal direction.  However, scaling is not always the correct
+% answer, since it affects all rule widths and character sizes, for
+% example.  You can see the input for the swelled rule in 
+% Figure~\ref{swelled-code}, taken from~Peter~\cite{peter2005}.
+%
+% \begin{figure}
+% \centering
+% \bigskip
+% \usempost{swelled}\\*[3ex]
+% \begin{minipage}{.5\linewidth}
+%\begin{verbatim}
+%\begin{mpost}[name=swelled]
+%breadth=.667\mpdim{\linewidth};
+%height=2pt;
+%x1=0;
+%x2=x6=.333x4;x5=x3=.667x4;
+%x4=breadth;
+%y1=y4=height/2;
+%y2=y3=height;
+%y5=y6=0;
+%fill z1--z2--z3--z4--
+%  z5--z6--cycle;
+%\end{mpost}
+%\end{verbatim}
+% \end{minipage}\\*[3ex]
+% \usempost{swelled}
+%
+% \bigskip
+% \caption{The code for the swelled rule}\label{swelled-code}
+% \end{figure}
+%
+% The command \cmdname{mpdim} takes as an argument a length (rigid or
+% rubber) and transforms it into a dimension understood by \MP{}
+% (i.e., it strips off possible `plus' and `minus' specifications).  To
+% \MP{} eyes, it is an `unnamed variable' like `\texttt{whatever}',
+% except that it has the value of the dimension given as argument; see
+% the description in Section~\ref{commands}
+%
+% What I did was to define a \MP{} input for the swelled rule, to
+% assign it a name and to use it when needed.  For example, the above
+% verbatim environment surrounded by swelled rules has been written as
+% in Figure~\ref{averb}.
+%
+% \begin{figure}
+% \centering\catcode`!=\active \def!{}
+% \begin{minipage}{.5\linewidth}
+%\begin{verbatim}
+%\begin{center}
+%\usempost{swelled}\\*[3ex]
+%\begin{minipage}{.5\linewidth}
+%\begin!{verbatim}
+%\begin{mpost}[name=swelled]
+%breadth=.667\mpdim{\linewidth};
+%...
+%\end{mpost}
+%\end!{verbatim}
+%\end{minipage}\\*[3ex]
+%\usempost{swelled}
+%\end{center}
+%\end{verbatim}
+% \end{minipage}
+% \caption{The input for the nice verbatim}\label{averb}
+% \end{figure}
+%
+% A recent message on \texttt{comp.text.tex}\footnote{\messageurl}
+% asked how to realize in \LaTeX{} chapter headers like the ones in
+% the manual ``Con\TeX{}t, an
+% excursion''\footnote{\texttt{http://www.pragma-ade.nl/general/manuals/mp-cb-en.pdf}}
+% and Taco Hoekwater kindly provided the code that's used. Here I
+% propose a macro that solves the problem, once it's integrated in a
+% chapter style for \textsf{memoir} or \textsf{titlesec}; the \MP{}
+% code is found in table~\ref{taco} and the result is shown here
+% \begin{center}
+% \bigskip
+% \tacochapterhead{How to draw graphics}
+% \bigskip
+% \end{center}
+% Now you can return to the first page and see that the title for the
+% introduction was typeset inside a similar drawing, but of different
+% size. The \MP{} code is exactly the same as Taco's, except for the
+% call of \texttt{mpost} instead of \cmdname{startMPgraphic} and
+% \cmdname{endMPgraphic}. The \LaTeX{} code used is
+%\begin{verbatim}
+%\newsavebox{\tacochapterbox}
+%\newcommand{\tacochapterhead}[1]{%
+%  \sbox\tacochapterbox{\Large\bfseries #1}%
+%  {\ooalign{%
+%     \MPclipOne{\mpdim{\wd\tacochapterbox+6pc}} % width
+%               {\mpdim{\ht\tacochapterbox+3pc}} % height
+%               {8}                              % thickness of the curve
+%               {(.7,.7,.7)}                     % color of the curve
+%               {red}                            % color of the spots
+%     \cr\hfill\raisebox{\dimexpr.5\ht\tacochapterbox+1.5pc\relax}
+%          {\box\tacochapterbox}\hfill}}}
+%
+%\tacochapterhead{How to draw graphics}
+%\end{verbatim}
+% Use a high level package such as \textsf{titlesec} in order to draw
+% fancy ornaments around the chapter title; an example might be
+%\begin{verbatim}
+%\newcommand{\chapformat}[1]{\tacochapterhead{\thechapter.\ #1}}
+%\titleformat{name=\chapter}[block]
+%  {\large\bfseries\filcenter}{}{0pt}{\chapformat}
+%\titleformat{name=\chapter,numberless}[block]
+%  {\large\bfseries\filcenter}{}{0pt}{\tacochapterhead}
+%\end{verbatim}
+% which takes care also of numberless chapter headings.
+%
+% \begin{table}
+% \caption{\MP{} code for a fancy chapter heading}\label{taco}
+%\begin{verbatim}
+%%macro arguments:
+%%#1 = desired width
+%%#2 = desired height
+%%#3 = pen thickness (relative)
+%%#4 = line color
+%%#5 = dot color
+%\def\MPclipOne#1#2#3#4#5%
+%   {\begin{mpost}
+%      w := #1;  width  := 100;  wfactor := w/width;
+%      h := #2;  height := 100;  hfactor := h/height;
+%      color lightred;  lightred  := (.90,.50,.50);
+%      color lightgray; lightgray := (.95,.95,.95);
+%      color gray;      gray      := (.50,.50,.50);
+%      def random_delta (expr d) =
+%        d-(uniformdeviate 2d)
+%      enddef;
+%      z1 = (0,height);
+%      z2 = (0,0);
+%      z3 = (width,0);
+%      z4 = (width,height);
+%      z5 = (width+random_delta(.2width),height+random_delta(.2height));
+%      z6 = (.5width+random_delta(.1width),height+random_delta(.1height));
+%      pickup pencircle
+%        xscaled (#3/wfactor)
+%        yscaled (#3/(2*hfactor))
+%        rotated 30;
+%      draw z5..z1..z2..z3..z4..z6 withcolor #4;
+%      pickup pencircle
+%        xscaled (#3/wfactor)
+%        yscaled (#3/hfactor);
+%      draw z1 withcolor #5;
+%      draw z2 withcolor #5;
+%      draw z3 withcolor #5;
+%      draw z4 withcolor #5;
+%      draw z5 withcolor #5;
+%      draw z6 withcolor #5;
+%      newwidth  := (xpart (urcorner currentpicture)) -
+%                   (xpart (llcorner currentpicture));
+%      newheight := (ypart (urcorner currentpicture)) -
+%                   (ypart (llcorner currentpicture));
+%      currentpicture := currentpicture
+%       xscaled (w/newwidth) yscaled (h/newheight);
+%    \end{mpost}}
+%\end{verbatim}
+% \end{table}
+%
+% Another useless application comes from the Metafun manual, by Hans
+% Hagen~\cite{hagen-metafun}: a representation of a counter using
+% vertical bars with a diagonal one after four of them, just like when
+% counting on a piece of scratch paper.  We can borrow the \MP{} input
+% from Hans, and define the command you find in table~\ref{scratch}.
+%
+% \begin{table}
+% \caption{The \texttt{\string\scratchcount} macro}\label{scratch}
+%\begin{verbatim}
+%\newcommand{\scratchcount}[1]{%
+%  \begin{mpost}
+%  n:=#1;
+%  height := 3/5\mpdim{\baselineskip} ; 
+%  span := 1/3 * height ; 
+%  drift := 1/10 * height ; 
+%  pickup pencircle scaled (1/12 * height) ; 
+%  def d = (uniformdeviate drift) enddef ; 
+%  for i := 1 upto n : 
+%    draw
+%      if (i mod 5)=0 : ((-d-4.5span,d)--(+d-0.5span,height-d))
+%      else : ((-d,+d)--(+d,height-d)) fi
+%      shifted (span*i,d-drift) ; 
+%  endfor; 
+%  picture cp ; 
+%  cp := currentpicture ; %for readability 
+%  setbounds currentpicture to
+%    (llcorner cp shifted (0,-ypart llcorner cp) --
+%     lrcorner cp shifted (0,-ypart lrcorner cp) --
+%     urcorner cp -- ulcorner cp -- cycle) ;
+%  \end{mpost}}
+%\makeatletter
+%\newenvironment{scratchenum}{\begin{enumerate}
+%  \@namedef{label\@enumctr}{\scratchcount{\arabic{\@enumctr}}}%
+%  }{\end{enumerate}}
+%\makeatother
+%\end{verbatim}
+% \end{table}
+%
+% Now we have a new environment and we can use it at every nesting 
+% level:
+% \begin{enumerate}
+% \item A first item, to remember that \MP{} is a big fun, for the 
+% following reasons:
+% \begin{scratchenum}
+% \item it has a syntax very similar to \MF;
+% \item it outputs very good PostScript;
+% \item there are many people using it;
+% \item it is very simple to use;
+% \item it integrates easily with \LaTeX;
+% \item some other reason just to arrive to six.
+% \end{scratchenum}
+% \item A second item, to remember that \LaTeX{} users can benefit from
+% the use of \MP{}.
+% \end{enumerate}
+% The input for this nested enumeration was
+%\begin{verbatim}
+%\begin{enumerate}
+%  \item A first ...
+%    \begin{scratchenum}
+%      \item it has ...
+%      ...
+%    \end{scratchenum}
+%  \item A second ...
+%\end{enumerate}
+%\end{verbatim}
+%
+% Of course, if we need to use the \texttt{scratchenum} only at the
+% first level of nesting, a definition such as
+%\begin{verbatim}
+%\newenvironment{scratchenum}
+%  {\begin{enumerate}
+%   \renewcommand{labelenumi}{\scratchcount{\arabic{enumi}}}%
+%  }
+%  {\end{enumerate}}
+%\end{verbatim}
+% would have sufficed.  We give as argument to \cmdname{scratchcount}
+% the representation of the counter as an arabic number; \MP{} does
+% all the necessary calculations.
+%
+% \begin{figure}
+% \centering
+%\begin{verbatim}
+%\newcommand\lista[2][black]{%
+%\VCEN{\begin{mpost}[mpmem=metafun]
+%n:=#2 ; color fuzzy_color ; fuzzy_color:=#1 ;
+%
+%height := 5pt ;
+%span := 1/3 * height ; 
+%drift := 1/10 * height ; 
+%hsize := .7\mpdim{\linewidth} ;
+%vstep := 10pt ; 
+%xmax := hsize div 5span ;
+%
+%pickup pencircle scaled (1/12 * height) ; 
+%def d = (uniformdeviate drift) enddef ; 
+%for i := 1 upto n : 
+%  xpos := ((i-1) mod (5*xmax))*span ;
+%  ypos := ((i-1) div (5*xmax))*vstep ;
+%  draw
+%    if (i mod 5)=0 : ((-d-4.5span,d)--(+d-0.5span,height-d))
+%    else : ((-d,+d)--(+d,height-d)) fi
+%    shifted (xpos,-ypos+d-drift) withcolor fuzzy_color ; 
+%endfor; 
+%
+%picture cp ; 
+%cp := currentpicture ; % for readability 
+%if (ypart ulcorner cp - ypart llcorner cp) <= vstep :
+%setbounds currentpicture to
+%  (llcorner cp shifted (0,-ypart llcorner cp) --
+%   lrcorner cp shifted (0,-ypart lrcorner cp) --
+%   urcorner cp -- ulcorner cp -- cycle) ;
+%fi
+%\end{mpost}}}
+%\end{verbatim}
+% \caption{Expanded definition for the scratch numbers; the
+% \protect\cmdname{VCEN} macro is for centering the object.}\label{expan}
+% \end{figure}
+%
+% We can expand on this theme, to represent greater numbers. You can 
+% see it in Figure~\ref{expan}. After this, an input like
+%\begin{verbatim}
+%\begin{tabular}{llr}
+%\multicolumn{2}{c}{\textbf{La lista}}\\\hline\\
+%Italia & \lista[red]{640} & 640\\\\
+%Alemagna & \lista{231} & 231\\\\
+%Francia & \lista[red]{100}& 100\\\\
+%Turchia & \lista{91}& 91\\\\
+%Spagna & \lista[red]{1003} & 1003\\\\\hline
+%\end{tabular}
+%\end{verbatim}
+% gives what you can see in figure~\ref{lalista}, but if we put it
+% inside a \texttt{minipage}, we can render the same list in other
+% ways, automatically.  You see it in Figure~\ref{liste}.
+%
+% \begin{figure}
+% \caption{La lista}\label{lalista}
+% \centering
+% \medskip
+% \begin{tabular}{llr}
+% Italia & \lista[red]{640} & 640\\\\
+% Alemagna & \lista{231} & 231\\\\
+% Francia & \lista[red]{100}& 100\\\\
+% Turchia & \lista{91}& 91\\\\
+% Spagna & \lista[red]{1003} & 1003\\
+% \end{tabular}
+%
+% \medskip
+% \end{figure}
+%
+% \begin{figure}
+% \centering
+% \scalebox{.7}{%
+% \begin{minipage}{.5\linewidth}
+% \begin{tabular}{ll}
+% \multicolumn{2}{c}{\textbf{La lista}}\\\hline\\
+% IT & \lista[red]{640}\\\\
+% DE & \lista{231}\\\\
+% FR & \lista[red]{100}\\\\
+% TR & \lista{91}\\\\
+% ES & \lista[red]{1003}\\\\\hline
+% \end{tabular}
+% \end{minipage}
+% \quad
+% \begin{minipage}{.4\linewidth}
+% \begin{tabular}{ll}
+% \multicolumn{2}{c}{\textbf{La lista}}\\\hline\\
+% IT & \lista[red]{640}\\\\
+% DE & \lista{231}\\\\
+% FR & \lista[red]{100}\\\\
+% TR & \lista{91}\\\\
+% ES & \lista[red]{1003}\\\\\hline
+% \end{tabular}
+% \end{minipage}}
+% \caption[]{The tables have been reduced at 70\%.  On the right the
+% table has been put in a \texttt{minipage}
+% of size \texttt{.5\cmdname{linewidth}}; on the left the size was 
+% \texttt{.4\cmdname{linewidth}}}\label{liste}
+% \end{figure}
+%
+% Note how we can pass to the \MP{} input some parameters, a
+% dimension as before, and a color specification.
+%
+% It is not necessary to put \texttt{mpost} environments inside a
+% definition, as we have already seen.  We can assign a name to the
+% object and use it as many times as we like, even subject to
+% transformations with the same syntax as \cmdname{includegraphics}. The
+% following example is from the \MP{} package \textsf{drv}, which
+% requires a double run of \MP{}:
+%\begin{verbatim}
+%\begin{mpost}[runs=2,mpsettings={input drv;},name=der1]
+%jgm 0 "A\vdash B";
+%jgm 1 "B\vdash C";
+%jgm 2 "A\vdash C";
+%nfr 0 () ("f", 1);
+%nfr 1 () ("g", 1);
+%nfr 2 (0, 1) ("\circ", 1);
+%draw drv_tree;
+%\end{mpost}
+%\usempost{der1}\quad
+%\usempost[angle=90]{der1}
+%\end{verbatim}
+% \begin{center}
+% \begin{mpost}[runs=2,mpxprogram=latex,
+%   mpsettings={input drv;},name=der1,use]
+% jgm 0 "A\vdash B";
+% jgm 1 "B\vdash C";
+% jgm 2 "A\vdash C";
+% nfr 0 () ("f", 1);
+% nfr 1 () ("g", 1);
+% nfr 2 (0, 1) ("\circ", 1);
+% draw drv_tree;
+% \end{mpost}\quad
+% \usempost[angle=90]{der1}
+% \end{center}
+%
+% If a \MP{} object is not assigned a name it is immediately used and,
+% obviously, it cannot be used any more.  Well, this is not strictly
+% true: every object has a number corresponding to an \textsc{mps} file
+% named \meta{filename}\texttt{+mp}\meta{number}\texttt{.mps} and it
+% would be possible to include it in the usual way.  Here
+% \meta{filename} is the name of the root \LaTeX{} file.  However, the
+% \meta{number} is not fixed, since insertion of other objects before a
+% certain one will change its assigned number.
+%
+% There are three ways for typesetting a document using \textsf{gmp},
+% which correspond to the following package options:
+% \begin{description}
+% \item[\texttt{shellescape}] exploits the `shell escape' feature
+% present in most \TeX{} distributions: every \texttt{mpost} environment
+% calls a run of \MP{}, setting the object immediately (you have to call
+% the typesetting engine with the necessary command line option, see
+% later);
+%
+% \item[\texttt{noshellescape}] defers the \MP{} runs to the end of
+% the \LaTeX{} run, the user has to launch them by hand---in this case a
+% very simple shell script is written for doing all the business;
+%
+% \item[\texttt{nowrite}] inhibits writing \MP{} files and disables
+% running \MP{}: when the document is finished and no more modifications
+% to the \MP{} objects are needed, we can set this option and read the
+% \textsc{mps} files already compiled in previous runs.
+% \end{description}
+%
+% The `shell escape' feature is very handy, but someone may feel uneasy
+% with it.  For security reasons, \TeX{} distributions usually disable
+% it by default and it must be explicitly requested by calling
+% \begin{flushleft}
+% \texttt{latex -shell-escape} \meta{filename}\\
+% \texttt{pdflatex -shell-escape} \meta{filename}\\
+% \texttt{xelatex -shell-escape} \meta{filename}
+% \end{flushleft}
+% depending on what engine you are using; see your system's
+% documentation for the actual call: for \TeX~Live the command line
+% option \texttt{-shell-escape}, while for MiK\TeX{} it's
+% \texttt{-enable-write18}.
+%
+% In case some \MP{} graphics doesn't compile properly, it's better to
+% switch to \texttt{noshellescape} and launch the shell script after a
+% new \LaTeX{} run: from a terminal window say
+% \texttt{sh~\meta{filename}+mp.sh}, where \meta{filename} stands for
+% your main document's name. This will run \MP{} in `error stop mode',
+% so that you'll probably get a clue about what is going wrong.
+%
+% If one uses \XeLaTeX{}, all \textsc{mps} files will be converted to
+% \textsc{pdf} via \texttt{epstopdf}.
+%
+%
+% \section{The name of the package and its workings}
+%
+% I wanted a successor of \textsf{emp}, but \textsf{fmp} was out of the
+% question: this is a package for including functional \MP{} in
+% \LaTeX. So I chose \textsf{gmp}.
+%
+% Here is a brief description of how the package works.  A \MP{}
+% object is defined through a \texttt{mpost} environment
+% (see~Section~\ref{envoptions}).  When such an environment is found,
+% an external \MP{} file is written and processed (either immediately
+% or after the \LaTeX{} run, at the user's choice).  After processing,
+% a file called \meta{filename}\texttt{+mp}\meta{number}\texttt{.mps}
+% is produced, which is then included in the \LaTeX{} output with
+% \cmdname{includegraphics}, but without user's intervention.  If the
+% object is assigned a name, it can be included as many times as
+% desired.
+%
+% The \textsf{gmp} package depends on \textsf{xkeyval},
+% \textsf{ifxetex}, \textsf{ifpdf} and, of course,
+% \textsf{graphicx}. If you have to pass options to this one, load it
+% before \textsf{gmp}.
+%
+%
+% \section{File names}
+%
+% This package \emph{doesn't} support file names containing
+% spaces. Quoting D.~E.~Knuth, if you're upset about this, you shouldn't
+% be: spaces in file names might be supported, but every system has its
+% idiosyncrasies and quotes around the name aren't always the correct
+% answer. Avoiding strange characters in file names is the best strategy
+% for being compatible with most platforms.
+%
+%
+% \section{To do}
+%
+% Find out a way to coerce creation of all auxiliary files in a
+% subdirectory of the current directory, in order not to fill it with
+% junk, besides what's really necessary.
+%
+%
+% \section{The package options}\label{options}
+%
+% We have seen some of the package options, but now I will present them
+% more formally.  Some of them will be grouped together; the first one
+% of the group is the default.
+%
+% \subsection{\texttt{tex} and \texttt{latex}}
+%
+% \MP{} is able to use either Plain \TeX{} or \LaTeX{} for typesetting
+% the `labels'.  If you are using ten point type and the usual Computer
+% Modern fonts or no label at all, it is not necessary to set this
+% option (the default is \texttt{tex}).  On the other hand, if you are
+% using different fonts or different type sizes, then \texttt{latex} is
+% necessary.  The package creates a crude preamble keeping the type size
+% of your document; insertion of any other package or of a different
+% class must be explicitly done with the commands \cmdname{usempxclass}
+% and \cmdname{usempxpackage} which have the same syntax as
+% \cmdname{documentclass} and \cmdname{usepackage}.  See
+% Section~\ref{commands} for a description of the commands; their names
+% should remember that they are used for an `extension' of \MP{}, namely
+% the preprocessor that typesets the labels making them into \MP{}
+% pictures. However the option can be overridden for any picture, see
+% later on.
+%
+% \subsection{\texttt{noshellescape} and \texttt{shellescape}}
+%
+% The \texttt{shellescape} option uses the \verb|\write18| feature found
+% in many \TeX{} distributions (all the up-to-date ones based on
+% \textsf{Web2C} such as \TeX~Live, and MiK\TeX{}).  Its purpose is to
+% stop momentarily the \TeX{} compilation for executing the \MP{} run
+% after a \texttt{mpost} environment has been found.  \LaTeX{} or
+% \textsc{pdf}\LaTeX{} have to be called with the \texttt{-shell-escape}
+% command line option or \texttt{-enable-write18} on MiK\TeX.
+%
+% With \texttt{noshellescape} all shell commands are collected in a
+% batch file and \LaTeX{} will remember users to execute it at the end
+% of the run.  On the subsequent \LaTeX{} run, all objects should be in
+% place.
+%
+% When a compiled \MP{} object is not found at the proper place, a box
+% like the one in the%
+% \marginpar[\hfill\csname gmp@box\endcsname]{\csname gmp@box\endcsname}%
+% margin is printed.  The same will happen in presence of compilation
+% errors, precisely when the proper \textsc{mps} file is not found.
+%
+% When using the \texttt{noshellescape} option, it may happen that
+% after a compilation the objects are misplaced, for example if some
+% new object has been added; running \MP{} on the created files and
+% another \LaTeX{} run should fix this. The default option is
+% \texttt{noshellescape}.
+%
+%
+% \subsection{\texttt{write} and \texttt{nowrite}}
+%
+% The \texttt{nowrite} option is useful when all \MP{} objects are
+% present in the document, they are in their final form and all of
+% them have been processed.  By setting the \texttt{nowrite} option,
+% no writing of \MP{} files and no compilation take place, speeding up
+% the process.  I would have called this option \texttt{final} and its
+% contrary \texttt{draft}, but this usage conflicts with the workings
+% of \textsf{graphicx}. The default option is \texttt{write}, so it's
+% not necessary to specify it.
+%
+%
+% \subsection{\texttt{envname}}
+%
+% You can change the name of the environment for the \MP{} objects;
+% the default is \texttt{mpost}.  If you don't like it or you want this
+% name for your favorite environment, you can say
+% \begin{flushleft}
+% \texttt{envname=}\meta{string}
+% \end{flushleft}
+% and \meta{string} will be used for introducing \MP{} objects. This
+% key must be specified only as a package option, not in the argument
+% of \cmdname{gmpoptions}.\footnote{Actually it can be in
+% \cmdname{gmpoptions}, but there it has no effect.}
+%
+%
+% \subsection{\texttt{extension}}
+%
+% If the root \LaTeX{} file is called \texttt{file}, then the compiled
+% \textsc{mps} files will be named
+% \texttt{file+mp}\meta{number}\texttt{.mps}. The string \texttt{+mp} is
+% the \emph{mp-extension}, which can be modified by saying
+% \begin{flushleft}
+% \texttt{extension=}\meta{string}
+% \end{flushleft}
+% in the options to \textsf{gmp}; the \meta{string} should consist only
+% of printable ASCII characters with no special meaning to \TeX{}. So,
+% with a main file called \texttt{paper.tex}, the created files will be
+% named \texttt{paper+mp0001.mp} and so on; with
+%\begin{verbatim}
+%\gmpoptions{extension=--mp--}
+%\end{verbatim}
+% the names will be \texttt{paper--mp--0001.mp} and so on. \emph{Don't
+%   use a slash} in the mp-extension! Leave this option to the default
+% value, unless you happen to have files whose name contains the string
+% \texttt{+mp}.
+%
+%
+% \subsection{\texttt{everymp}}
+%
+% Here you can set whatever you want to be present in all \MP{}
+% objects, for example input files.  Any set of \MP{} statements
+% can be given in braces, for example
+%\begin{verbatim}
+%everymp={input boxes;}
+%\end{verbatim}
+% Since these are \MP{} statements, don't forget the trailing
+% semicolon. If you have a long list of \MP{} macros that should be
+% loaded for each picture, it's better to save them in a file and input
+% this one with the \texttt{everymp} key. When your document uses font
+% packages, you may need to say
+%\begin{verbatim}
+%everymp={prologues=3;}
+%\end{verbatim}
+% so that your \textsc{mps} files will contain correct references to
+% the fonts; this is automatically done when the typesetting engine is
+% \XeLaTeX{}.
+%
+% \subsection{\texttt{clean=none\string|aux\string|mp}}
+%
+% After the compilation, there will be many auxiliary files around. The
+% essential ones are only those necessary for the picture inclusion,
+% namely the \textsc{mps} or \textsc{pdf} final results. With
+% \texttt{clean=none} nothing will be removed, with \texttt{clean=aux}
+% the files with extension \texttt{.log}, \texttt{.mpx} and
+% \texttt{.mpo} created during the \MP{} runs will be deleted. Also the
+% \texttt{.mp} files will be deleted with \texttt{clean=mp}; this option
+% will erase also the \texttt{.mps} files when \XeLaTeX{} is used.
+%
+% Some strange files will remain, particularly when there's some error
+% during one of the \MP{} runs; this is why I chose not to delete them.
+% It's best to use \texttt{clean=none}, which is the default, at the
+% beginning, changing to \texttt{clean=aux} when everything seems to be
+% alright and \texttt{clean=mp} for the last check before setting
+% \texttt{nowrite}.
+%
+% In case you are worried about what files will be deleted, run with the
+% \texttt{noshellescape} options and have a look at the shell script
+% that's created: it will show at its end the remove commands that will
+% be run. Or just don't set anything, so that \texttt{clean=none} will
+% be in force.
+%
+%
+% \subsection{\texttt{rmcommand}}
+%
+% The default command for cleaning the directory is \texttt{rm~-f}. Of
+% course this is system dependent and those on
+% Windows$^{\scriptscriptstyle\mathrm{TM}}$ systems might want to set
+% \texttt{rmcommand=del}.
+%
+% \subsection{\texttt{postrmcommand}}
+% The value of the key \texttt{postrmcommand} is usually empty; you can
+% obtain a `safe removing' by setting something like
+%\begin{verbatim}
+%\gmpoptions{rmcommand=mv,postrmcommand=junk}
+%\end{verbatim}
+% This will be translated into commands such as
+%\begin{verbatim}
+%mv filename+mp*.log junk
+%\end{verbatim}
+% so if you have a subdirectory called \texttt{junk} all the auxiliary
+% files will be moved into it, instead of being deleted.
+%
+%
+% \section{Commands}\label{commands}
+%
+%
+% \subsection{\cmdname{gmpoptions}\marg{\meta{options}}}
+%
+% All package options can be given either as an optional argument to
+% \cmdname{usepackage} or as an argument to \cmdname{gmpoptions}.  This
+% command can be given multiple times, with cumulative effect, but only
+% in the preamble. However the \texttt{envname} option has no effect
+% here.
+%
+%
+% \subsection{\cmdname{usempxclass}%
+%   \oarg{\meta{options}}%
+%   \marg{\meta{class}}}
+%
+% This has the same syntax as \cmdname{documentclass}.  Its purpose is
+% to declare the class used for the runs of \TeX{} or \LaTeX{} for
+% preparing the \texttt{mpx} files which \MP{} needs to draw the text
+% labels.  It should be not necessary to change it from the default
+% (which is \texttt{article}).  But if you are using a non standard
+% class with a non standard type size (i.e., not 10, 11 or 12 point
+% size), then you \emph{will need} to declare a class, otherwise your
+% labels will be typeset in 10~point type.  Of course this has no effect
+% for \MP{} objects where the \TeX{} format to be used is Plain~\TeX{}.
+%
+%
+% \subsection{\cmdname{usempxpackage}%
+%   \oarg{\meta{options}}%
+%   \marg{\meta{package\textup(s\textup)}}}
+%
+% Same syntax as \cmdname{usepackage}.  It can be given multiple times
+% and its effects are cumulative.  Thus, if your main text font is
+% Palatino, you have to give
+%\begin{verbatim}
+%\usepackage{palatino}
+%\usempxpackage{palatino}
+%\end{verbatim}
+% I chose not to modify the standard \cmdname{usepackage} command
+% because some packages make no sense inside \MP{} objects and it
+% would be useless and time consuming to load them.  Just think to the
+% \textsf{pgf} package, for example: while a user may very well employ
+% this one alongside with \textsf{gmp}, it would be very questionable to
+% load \textsf{pgf} during a \LaTeX{} run to compile a \MP{} graphic
+% object, albeit not forbidden.
+%
+% If your labels in \MP{} pictures use special characters (the accented
+% ones, for instance), you \emph{must} load the \textsf{inputenc} package
+% \emph{with the same option} as your main file:
+%\begin{verbatim}
+%...
+%\usepackage[latin1]{inputenc}
+%...
+%\usepackage{gmp}
+%\gmpoptions{...}
+%\usempxpackage[latin1]{inputenc}
+%...
+%\end{verbatim}
+% You can use any encoding with (\textsc{pdf})\LaTeX{}; set the
+% \texttt{utf8} or \texttt{utf8x} option when your main document is
+% typeset with \XeLaTeX{}.
+%
+% Both \cmdname{usempxpackage} and \cmdname{usempxclass} respect the
+% usual scoping rules, so you can modify the class or the packages used
+% for a particular \MP{} object by enclosing the commands in a group,
+% for example in an environment such as \texttt{figure}.  But no, not in
+% the \texttt{mpost} environment itself, sorry.
+%
+%
+% \subsection{\cmdname{resetmpxpackages}}
+%
+% This command resets to empty the list of packages to be loaded,
+% obeying to the normal scoping rules.
+%
+%
+% \subsection{\cmdname{mpxcommands}\marg{\meta{commands}}}
+%
+% With this command you can add \LaTeX{} commands to be executed for
+% every run of \MP{}, when typesetting labels; for instance, your
+% favorite definitions.  Also the effect of this command is cumulative.
+% Pay attention that this works only if the program used for compiling
+% the \texttt{mpost} figures is \LaTeX{}.  Like the commands for
+% choosing the class and the packages, this one obeys the scoping rules.
+%
+% \subsection{\cmdname{resetmpxcommands}}
+%
+% This command resets the list of commands to empty, obeying to the
+% normal scoping rules.
+%
+%
+% \subsection{\cmdname{mpdim}\marg{\meta{dimen parameter}}}
+%
+% This command takes as argument a length, i.e., a \LaTeX{} parameter or
+% a command defined by \cmdname{newlength} or operations on lengths.
+% Its output is the length in points; if the length is a rubber one, the
+% `plus' and `minus' parts are ignored.  You can even use as argument an
+% explicit length such as `\texttt{2cm}', although this would be
+% overkill. However, you can give as argument some calculation with
+% \cmdname{dimexpr} syntax, such as
+%\begin{verbatim}
+%\mpdim{2ex+\baselineskip}
+%\mpdim{3em-1pt}
+%\end{verbatim}
+% which might be useful, because the \texttt{ex} and \texttt{em} units
+% change with the current font size. Don't add \cmdname{relax}, it's
+% automatically provided.
+%
+% \begin{annotation}
+% \TeX{}nical note.  The command \cmdname{mpdim} works without making
+% assignments, so that it is fully expandable at the moment of the
+% \cmdname{write} to the \MP{} external file.  It uses internally
+% \cmdname{the} and \cmdname{dimexpr}.  When the \cmdname{write} takes
+% place, the command is expanded and the output is
+% \begin{flushleft}
+% \ttfamily
+% begingroup \meta{thedimen} endgroup
+% \end{flushleft}
+% where \meta{thedimen} is the value of the \meta{dimen} given as
+% argument.  Therefore the construction
+% \cmdname{mpdim}\marg{\meta{dimen}} behaves like a number as far as
+% \MP{} is concerned; for Metapost, dimensions are simply numbers and
+% the units are just multipliers.
+% \end{annotation}
+%
+%
+% \subsection{\cmdname{usempost}}
+%
+% This command takes as its argument a string already assigned as a name
+% to a \MP{} object.  Its effect is to place the graphic object where
+% the command appears. The complete syntax is
+% \begin{flushleft}
+% \cmdname{usempost}\oarg{\meta{options}}\marg{\meta{string}}
+% \end{flushleft}
+% where \meta{string} is the name of an already introduced and named
+% \MP{} object and \meta{options} are any options that make sense for
+% the \cmdname{includegraphics} command provided by the
+% \textsf{graphicx} package.
+%
+%
+% \section{Environments}
+%
+% The package provides two environments, whose default names are
+% \texttt{mpost} and \texttt{mpost*}. The name, however, can be changed
+% in the package options, as we have already seen. In the descriptions
+% below I'll use the default name.
+%
+% Commands in the body of the \texttt{mpost} environment \emph{are}
+% interpreted and expanded and this is the main feature offered by this
+% package.
+%
+% The main difference between \texttt{mpost} and \texttt{mpost*} is that
+% in the second one there is no expansion at all: every \MP{} statement
+% in the environment's body is written out as it is for subsequent
+% processing. Therefore \texttt{mpost*} behaves like \texttt{emp} or
+% \texttt{mpgraphics} of the respective packages, but the difference is
+% that it \emph{can} go in the argument to a command. This behavior
+% costs us something: \LaTeX{} environments in \MP{} labels \emph{must}
+% be enclosed in a pair of braces in the same \texttt{btex...etex}
+% construction. So don't say
+% \begin{flushleft}\color{red}
+%\begin{verbatim}
+%btex ... $\begin{array}{c}a\\b\end{array}$ ... etex
+%\end{verbatim}
+% \end{flushleft}
+% but rather
+%\begin{verbatim}
+%btex ... {$\begin{array}{c}a\\b\end{array}$} ... etex
+%\end{verbatim}
+% See later on for details. The same holds for the \texttt{mpost}
+% environment, with one more little catch, see page~\pageref{btex}.
+%
+% There is no |\inputmpost| command: if you really need it, just
+% define
+%\begin{verbatim}
+%\newcommand{\inputmpost}[2][1]{\begin{mpost}[#1]input #2;\end{mpost}}
+%\end{verbatim}
+% The \MP{} file you input this way should contain just statements
+% that would go in a normal \texttt{mpost} environment.
+%
+%
+% \section{Options to the environments}\label{envoptions}
+%
+% Actually, the name of the two environments provided by this package
+% can be chosen by the user on a per document basis with the package
+% option \texttt{envname}.  I will use the default name in the
+% description. The syntax is
+% \begin{flushleft}
+% \cmdname{begin}\marg{mpost}\oarg{\meta{options}}\\
+% \meta{\MP{} statements}\\
+% \cmdname{end}\marg{mpost}\\[3ex]
+% \verb|\begin{mpost*}[|\meta{options}\verb|]|\\
+% \meta{\MP{} statements}\\
+% \verb|\end{mpost*}|
+% \end{flushleft}
+%
+% The \meta{options} are in the form \meta{key}\texttt{=}\meta{value}.
+% They influence only the current environment and are the same for the
+% two varieties (\texttt{mpost} and \texttt{mpost*}).
+%
+%
+% \subsection{\texttt{name}}
+%
+% With \texttt{name=}\meta{string} you assign the object a name for
+% subsequent multiple use with \cmdname{usempost}\marg{\meta{string}}.
+% For example, if the object is some symbol to be employed many times, 
+% you can say
+%\begin{verbatim}
+%\begin{mpost}[name=mysymbol]
+%...
+%\end{mpost}
+%\newcommand{\mynicesymbol}{%
+%  \usempost[height=.7\ht\strutbox]{mysymbol}}
+%\end{verbatim}
+% In this case you cannot pass arguments to the \texttt{mpost}
+% environment: the object is \emph{frozen} apart from modifications with
+% the optional argument to \cmdname{usempost}. In this case the symbol
+% we have built with \MP{} will change size according to the current
+% font size, but only by scaling.
+%
+% The \meta{string} used as a name should consist only of ASCII
+% printable characters; no accented letters, please, just like for
+% \LaTeX{} labels (those for \cmdname{label}). If you specify this key,
+% then the object will not appear unless you specify also \texttt{use},
+% see below. The proper place for named environments is usually the
+% preamble.
+%
+% \begin{annotation}
+% Suppose you have to write the symbol for a square wave in different
+% sizes; instead of using only one \textsc{mps} graphic file and scaling
+% it you may want to define a couple of them. Say, for instance, that
+% you need it also in section titles, which are typeset in
+% \cmdname{Large} size and bold face and that the symbol's height is the
+% same as a lowercase letter. You can get the two versions which are
+% automatically chosen among with the following code:
+%\begin{verbatim}
+%\makeatletter
+%\newcommand{\sqwave}{\usempost{sqwave\f@size\f@series}}
+%\newcommand{\sqwavebody}{%
+%  u:=\mpdim{1ex};
+%  pickup pencircle scaled \mpdim{.05em};
+%  draw (0,0)--(2/3u,0)--(2/3u,u)--(u,u)--(u,0)--(5/3u,0);}
+%{\normalsize
+%\begin{mpost}[name=sqwave\f@size\f@series]\sqwavebody\end{mpost}
+%}
+%{\Large\bfseries
+%\begin{mpost}[name=sqwave\f@size\f@series]\sqwavebody\end{mpost}
+%}
+%\makeatother
+%\end{verbatim}
+% Then simply say \cmdname{sqwave} when you need the symbol.  If you
+% change the type size of your document, you'll get the proper symbol's
+% height.  If it turns out that you need the symbol also in other
+% contexts, just add other \texttt{mpost} named environments along the
+% same lines.
+%
+% We pass the \texttt{mpost} environment two dimensions that depends on
+% the context: the symbol's height will be the x-height of the current
+% font, the pen's width will scale according to the em size, which is
+% bigger for bold face fonts. The picture will be chosen according to
+% the current value of \cmdname{f@size} (the current type size) and
+% \cmdname{f@series}, which contains the font series indicator (`m' for
+% medium fonts and `bx' for bold face fonts, usually). The auxiliary
+% macro \cmdname{sqwavebody} contains the body of the \texttt{mpost}
+% environment, so there's even no need to copy it many times.
+% \end{annotation}
+%
+%
+% \subsection{\texttt{use}}
+% This is a boolean option, the default is \texttt{true} unless the
+% \texttt{name} option is present.  When it is set to \texttt{true},
+% the object is inserted in the place where the environment appears.  In
+% order to set it to \texttt{true}, it is sufficient to say \texttt{use}
+% instead of \texttt{use=true}.
+%
+% \subsection{\texttt{mpmem}}
+% You can choose a different format for \MP{} compilation instead of
+% the default Plain.  For example you can use Hans Hagen's Metafun
+% package by passing the option
+% \begin{flushleft}
+% \texttt{mpmem=metafun}
+% \end{flushleft}
+%
+% \subsection{\texttt{mpxprogram}}
+%
+% With this option, you can override the global option chosen when
+% \textsf{gmp} was loaded, or with \cmdname{gmpoptions}; with
+% \texttt{mpxprogram=tex} you invoke Plain \TeX{}, with
+% \texttt{mpxprogram=latex} you invoke \LaTeX{} with the preamble
+% defined by default or in the options to \textsf{gmp}.  There are
+% presently no other choices. Use \texttt{mpxprogram=latex} (or set the
+% package option \texttt{latex}) whenever you have \MP{} labels.
+%
+%
+% \subsection{\texttt{mpxcommands}}
+%
+% You can pass some commands to be executed when compiling \MP{} with
+% \LaTeX{} with \texttt{mpxcommands=}\meta{commands}. For instance, you 
+% can say
+%\begin{verbatim}
+%mpxcommands={\newcommand{\C}{\mathbf{C}}}
+%\end{verbatim}
+% if your labels contain a \cmdname{C} command for typesetting the set
+% of complex numbers in bold face type or some other useful commands.
+% You may also say
+%\begin{verbatim}
+%mpxcommands={\input{mymacros}}
+%\end{verbatim}
+% and put all needed definitions inside \texttt{mymacros.tex}.  Remember
+% that inside \verb|\btex...etex| constructions (see
+% Section~\ref{body}), \MP{} does \emph{not} know any of your personal
+% commands, since the typesetting is made during a distinct run of
+% \LaTeX{}. The \LaTeX{} commands are not interpreted during the write
+% to the auxiliary file, they will be during \MP{} compilation.
+%
+% \subsection{\texttt{mpsettings}}
+%
+% The value for this key is a list of \MP{} statements to be executed
+% \emph{before} \texttt{beginfig}, usually for inputting \MP{}
+% packages. For example, if a \MP{} object is drawn with the 
+% \textsf{boxes} package, then it is necessary to say
+%\begin{verbatim}
+%mpsettings={input boxes;}
+%\end{verbatim}
+% because this package must be loaded before saying \texttt{beginfig}.
+% Of course such a statement can be included also with the
+% \texttt{everymp} global key.  Don't forget the trailing semicolon.
+% \LaTeX{} commands are interpreted just as in the \texttt{mpost}
+% environment, so it's possible to use, for example, \cmdname{mpdim}.
+%
+% \subsection{\texttt{runs}}
+%
+% The \textsf{drv} package for \MP{} requires each source file to be
+% run twice; in this case set the option \texttt{runs=2}. For this
+% specific package it's necessary to use also the \texttt{latex}
+% option and also, of course, \texttt{mpsettings={input drv;}} in
+% order to load the \MP{} package. The default value is~$1$.
+%
+%
+% \section{The body of the \texttt{mpost} and \texttt{mpost*}
+% environments}\label{body}
+%
+% The body of the \texttt{mpost} and \texttt{mpost*} environments
+% consists of \MP{} statements with the exception of
+% \texttt{beginfig(\meta{number});}, \texttt{endfig;} and
+% \texttt{end}\footnote{Actually, you \emph{can} put such statements;
+% but don't blame me if your computer starts choking or insulting
+% you.}.
+%
+% The \MP{} input that will be processed consists of
+% \begin{flushleft}
+% \meta{\TeX{} preamble}\\
+% \meta{\MP{} preamble}\\
+% \texttt{beginfig(\meta{number});}\\
+% \meta{body of the environment}\\
+% \texttt{endfig;end}\\
+% \meta{\TeX{} postamble}
+% \end{flushleft}
+% The \meta{body of the environment} is precisely the contents of the
+% \texttt{mpost} environment you supply. The \meta{number} is assigned
+% automatically and is actually irrelevant.
+%
+% The \meta{\TeX{} preamble} is empty if the compiler for the
+% \texttt{mpx} files is \TeX{}; it is the \LaTeX{} preamble formed as
+% seen before in case the compiler is \LaTeX{}.  In the latter case, the
+% \meta{\TeX{} postamble} is just
+%\begin{verbatim}
+%verbatimtex \end{document} etex
+%\end{verbatim}
+% otherwise it is empty (the \MP{} interpreter knows to add
+% \verb|\end| at the end of its produced \texttt{mpx} file, if
+% necessary). Of course the \meta{\TeX{} preamble} is complemented by
+% the declarations you supply with the previously described commands.
+% Similarly, the \meta{\MP{} preamble} is usually almost empty, but
+% you may add something with the methods described earlier; actually the
+% only statement always added to the preamble is
+%\begin{verbatim}
+%outputtemplate:= "%j.mps";
+%\end{verbatim}
+% in order to give the resulting file a suitable name for automatic
+% inclusion in the \LaTeX{} document. Don't issue such a statement
+% yourself.
+%
+% In the \meta{body of the environment} you can put \TeX{} or \LaTeX{}
+% commands as usual for \MP{} code inside \texttt{btex \meta{\TeX{}
+%     material} etex}; in a \texttt{mpost} environment, however,
+% \LaTeX{} commands may be embedded in the normal \MP{} statements,
+% we'll call them \emph{naked}.
+%
+%
+% \subsection{Naked \TeX{} commands in the body of
+%   \texttt{mpost}}
+%
+% The \emph{naked} commands will be expanded in the normal way, it's up
+% to you to ensure that their expansion is valid \MP{} code.  Don't
+% use dimension parameters by themselves: for example, the command
+% \cmdname{linewidth} is \emph{unexpandable}, so \MP{} will interpret
+% it as the variable \texttt{linewidth}, which probably would be
+% unknown.
+%
+% Suppose you want that your \MP{} graphic objects have a uniform aspect
+% throughout the document, but you haven't decided yet what will be the
+% final background color for a series of pictures. All you need is to
+% use something like
+%\begin{verbatim}
+%fill p withrgbcolor \backgroundcolor;
+%\end{verbatim}
+% and to give in the document's preamble a definition such as
+%\begin{verbatim}
+%\newcommand*{\backgroundcolor}{(.124,.048,.129)}
+%\end{verbatim}
+% and your backgrounds will be the same in all the pictures. Of course
+% there are other methods to get this result: one might say also
+%\begin{verbatim}
+%\gmpoptions{everymp={rgbcolor mybgcolor;
+%   mybgcolor:=(.124,.048,.129)}}
+%\end{verbatim}
+% or write a definition file to be read via \texttt{everymp}; but I
+% believe that the \emph{naked command} method is preferable from the
+% point of view of a \LaTeX{} user: it requires less maintenance and is
+% more direct.
+%
+% In order to pass length parameters to \MP{}, the \cmdname{mpdim}
+% command is useful.  If you know that the parameter is a fixed length
+% (such as \cmdname{linewidth}), you can use also \cmdname{the} before
+% the name of the length parameter.  Beware however that most parameters
+% in \LaTeX{} are defined through \cmdname{newlength} and so they are
+% \emph{rubber} length, possibly having `plus' or `minus' components
+% which would confuse \MP{}.  Using \cmdname{mpdim} is safer.
+% Moreover, \cmdname{mpdim} accepts its argument in the usual braced
+% form.
+%
+% Pay attention that the expansion of \cmdname{mpdim} is not only the
+% length in points, but something more complicated.  Don't use it
+% outside \texttt{mpost} environments.
+%
+% Any command whose expansion is just a string of characters can be used
+% naked in a \texttt{mpost} environment; \MP{} will see the string of
+% letters and it's under your responsibility that this string is
+% meaningful in the context it's found. For example, after
+%\begin{verbatim}
+%\newcommand{\xxx}[1]{#1cm}
+%\end{verbatim}
+% has been given in the \LaTeX{} root file, \cmdname{xxx}\marg{2} can be
+% written in a \texttt{mpost} environment, where \MP{} expects a
+% numeric value; for instance,
+%\begin{verbatim}
+%a:=\xxx{2};
+%\end{verbatim}
+% would set the variable `\texttt{a}' to the value `\texttt{56.6929}',
+% which are indeed two centimeters, since \MP{} works internally in
+% `big~points'. Pay attention that
+%\begin{verbatim}
+%a:=2\xxx{2};
+%\end{verbatim}
+% would set the variable `\texttt{a}' to the value `\texttt{623.62192}'
+% which corresponds to 22~centimeters and not to `\texttt{113.3858}'
+% (i.e., 4~centimeters). The correct way to set `\texttt{a}' to 
+% 4~centimeters would be \verb|a:=2*\xxx{2};|.
+%
+%
+% \subsection{Commands inside
+% \texttt{[verbatim\string|btex]...etex}}\label{btex}
+%
+% This is an important point where the \MP{} input in a
+% \texttt{mpost} environment deviates slightly from the normal
+% one. Suppose that you have to write a label inside \MP{} in the
+% form
+%\begin{verbatim}
+%btex \textit{label} etex
+%\end{verbatim}
+% because you want it in italics.  We have a problem here, because the
+% command \cmdname{textit} passes through a \cmdname{write}, so that it
+% is expanded to something that is not what the \MP{} interpreter
+% likes to see; precisely, the expansion might be something like
+%\begin{verbatim}
+%\protect \relax \protect \edef n{it}\protect\xdef 
+%\OT1/cmr/m/n/10 {\OT1/cmr/m/n/10 }\OT1/cmr/m/n/10
+%\size@update \enc@update
+%\end{verbatim}
+% (all on one line).  This will confuse the postprocessors that typeset
+% the labels (that currently are integrated into \MP{}), either if we
+% are using \LaTeX{} or, even worse, Plain \TeX{}.
+%
+% The solution is to write \cmdname{verbatimtex} and \cmdname{btex} 
+% instead of \texttt{verbatimtex} and \texttt{btex}. The leading 
+% backslash would be legal also in standard \MP{}, anyway. 
+% Everything inside
+%\begin{verbatim}
+%\verbatimtex ... etex
+%\btex ... etex
+%\end{verbatim}
+% is passed as is to the compiler for producing the \texttt{mpx} files
+% needed by \MP{}. So the correct way to pass the label is
+%\begin{verbatim}
+%\btex \textit{label} etex
+%\end{verbatim}
+% when post-processing with \LaTeX{} and
+%\begin{verbatim}
+%\btex \it label etex
+%\end{verbatim}
+% when post-processing with Plain \TeX{}. Though using \texttt{btex}
+% without a backslash has its uses, remember that eight bit characters
+% \emph{must} go inside \verb|\btex...etex| or protected by
+% \cmdname{unexpanded} (unless you're using \XeLaTeX{}). So, never say
+% \begin{flushleft}\color{red}
+% \verb|btex Cuvéé 1982 etex|
+% \end{flushleft}
+% but choose among the following alternatives:
+%\begin{verbatim}
+%\btex Cuvéé 1982 etex
+%btex \unexpanded{Cuvéé} 1982 etex
+%btex Cuv\unexpanded{éé} 1982 etex
+%\end{verbatim}
+%
+% \begin{annotation}
+% \TeX{}nical note.  When I started developing this package, the
+% choice to write verbatim the \MP{} input was ruled out almost
+% immediately, since I wanted to pass parameters from \LaTeX{} to
+% \MP{}.  The verbatim method is used by \textsf{emp}, which makes
+% available only two parameters given as arguments to the \texttt{emp}
+% environment; for example |\begin{emp}(23,45)| puts at the user's
+% disposal the two \MP{} variables `\texttt{w}' and `\texttt{h}' with
+% values $23$~times and $45$~times the usual \LaTeX{} parameter
+% \cmdname{unitlength}.  Passing to \MP{} the \cmdname{linewidth} is
+% pretty complicated, since it requires to divide the
+% \cmdname{linewidth} by the unit length.  Moreover, only two
+% parameters are too few.
+%
+% Therefore I chose to write the \MP{} files expanding commands.  This
+% works since \MP{} instructions have no backslashes in them and the
+% command \cmdname{mpdim} used for passing parameters from the current
+% document is especially tailored in order that its expansion is
+% accepted by \MP{}.  With the obvious exception of things inside
+% \texttt{btex...etex}.  The solution exploits the
+% \cmdname{unexpanded} command made available by the modern \TeX{}
+% engines.
+%
+% The construction \verb|\btex...etex| is equivalent to write
+%\begin{verbatim}
+%btex \unexpanded{...} etex
+%\end{verbatim}
+% and what is written to the \MP{} file is precisely
+%\begin{verbatim}
+%btex ... etex
+%\end{verbatim}
+% with no expansion of commands.
+% \end{annotation}
+%
+% There is another catch: for \TeX{}nical reasons, environments in
+% \verb|\btex...etex| parts cannot be used without protection.  This
+% is because the \MP{} input is gathered as an argument delimited by
+% \cmdname{end}.  The solution is to put the inner environments inside
+% braces.  An example, taken from Hoenig~\cite[p.~416]{hoenig}, is
+% found in figure~\ref{hoenigsun}, where the input is just like
+% Hoenig's except for a minor correction (\texttt{3.5u} in the
+% original should be \texttt{4.5u}) and having put everything inside
+% \verb|\btex...etex| in braces (and writing \cmdname{btex} instead of
+% \texttt{btex}, of course).
+%
+% \begin{figure}
+% \caption{An example from Alan Hoenig's book}\label{hoenigsun}
+%\begin{verbatim}
+%\begin{mpost}[mpxprogram=latex,mpsettings={input boxes;}]
+%u:=1pc; path p[]; p0=(-6u,0) -- (6u,0);
+%p1=(0,-4u)--(0,4u);
+%p2=(0,-4.5u)--(0,4.5u); p2:=p2 rotated -45;
+%circleit mech(\btex
+%{\fontsize{8}{10}\selectfont
+%$\begin{array}{c}
+%\sigma_{ij,j}=0\\
+%\sigma_{ij}=c_{ijk\ell}\epsilon_{k\ell}\\
+%\epsilon_{ij}=\frac{1}{2}(u_{i,j}+u_{j,i})
+%\end{array}$}
+%etex);
+%mech.dx=mech.dy; mech.c=origin;
+%pickup pencircle scaled 1pt;
+%draw p0; draw p1; draw p2; draw p2 rotated 90;
+%pickup pencircle scaled u; unfilldraw bpath.mech;
+%pickup pencircle scaled 1pt; drawboxed(mech);
+%\end{mpost}
+%\end{verbatim}
+%
+% \centering
+% \begin{mpost}[mpxprogram=latex,mpsettings={input boxes;}]
+% u:=1pc; path p[]; p0=(-6u,0) -- (6u,0);
+% p1=(0,-4u)--(0,4u);
+% p2=(0,-4.5u)--(0,4.5u); p2:=p2 rotated -45;
+% circleit mech(\btex
+% \fontsize{8}{10}\selectfont
+% $\array{c}
+% \sigma_{ij,j}=0\\
+% \sigma_{ij}=c_{ijk\ell}\epsilon_{k\ell}\\
+% \epsilon_{ij}=\frac{1}{2}(u_{i,j}+u_{j,i})
+% \endarray$
+% etex);
+% mech.dx=mech.dy; mech.c=origin;
+% pickup pencircle scaled 1pt;
+% draw p0; draw p1; draw p2; draw p2 rotated 90;
+% pickup pencircle scaled u; unfilldraw bpath.mech;
+% pickup pencircle scaled 1pt; drawboxed(mech);
+% \end{mpost}
+% \end{figure}
+%
+% Another way to cope with this would be to write simply \cmdname{array}
+% instead of \cmdname{begin}\marg{array} and \cmdname{endarray} instead
+% of \cmdname{end}\marg{array}, which is how the \texttt{mpost}
+% environment for this example has actually been written.
+%
+%
+% \section{Definitions using the \texttt{mpost} environment}
+%
+% Some examples have already been presented, but it's best to
+% underline again that the environment can go inside the replacement
+% text of a definition; don't use \cmdname{mpost} and
+% \cmdname{endmpost}, though, just |\begin{mpost}| and
+% |\end{mpost}|. Commands defined this way are \emph{fragile}: don't
+% use them in moving arguments. As an example, we can use a variation
+% on a drawing from~\cite{hoenig}:
+%\begin{verbatim}
+%\newcommand{\squares}[2][black]{%
+%  \begin{mpost}
+%  boolean timetofillbox;
+%  sfactor:=.95;
+%  path p,q; u:=\mpdim{#2\textwidth}/2;
+%  p := (u,u) -- (-u,u) -- (-u,-u) -- (u,-u) -- cycle;
+%  theta := 0; dtheta := .005;
+%  forever:
+%    theta := theta+dtheta;
+%    q := p scaled sfactor rotated theta;
+%    exitif ypart(point 0 of q) > u;
+%  endfor;
+%  fill p withrgbcolor #1; timetofillbox:=false;
+%  for i:=1 upto 51:
+%    p := p scaled sfactor rotated theta;
+%    if timetofillbox:
+%      fill p withrgbcolor #1; timetofillbox:=false;
+%    else:
+%      fill p withrgbcolor white-#1; timetofillbox:=true;
+%    fi
+%  endfor
+%  \end{mpost}}
+%\end{verbatim}
+% The optional argument is an \textsc{rgb} color, either with a
+% predefined name such as \texttt{black} (default) or a triple such as
+% \texttt{(.165,.325,.553)}; the second argument is the size of the
+% square, expressed as a fraction of \cmdname{textwidth}, for example
+% \texttt{0.8}. In figure~\ref{squares} you get three variations input
+% as
+%\begin{verbatim}
+%\begin{minipage}{\textwidth}
+%\centering\offinterlineskip
+%\squares{.4}\squares[(.165,.325,.553)]{.4}\\
+%\squares[(.835,.685,.447)]{.8}
+%\end{minipage}
+%\end{verbatim}
+% that also show how \textsf{gmp} uses the hi-res bounding box provided
+% by \MP{}.
+%
+% \begin{figure}
+% \medskip
+% \begin{minipage}{\textwidth}
+% \centering\offinterlineskip
+% \squares{.4}\squares[(.165,.325,.553)]{.4}\\
+% \squares[(.835,.685,.447)]{.8}
+% \end{minipage}
+% \medskip
+% \caption{Squares taken from Hoenig's book}\label{squares}
+% \end{figure}
+%
+%
+% \section{The \texttt{mpost*} environment}
+%
+% No command in the body of the \texttt{mpost*} environment will be
+% interpreted in any special way, so don't use them except than
+% encapsulated into \texttt{btex...etex}. Here there's no need to write
+% \cmdname{btex}, but it doesn't hurt either. It's however necessary to
+% hide inside braces the \LaTeX{} command \cmdname{end} like for the
+% sibling environment \texttt{mpost}. It's possible to pass variables to
+% the picture from the \LaTeX{} context by exploiting the option
+% \texttt{mpsettings}: for example, with a prologue such as
+%\begin{verbatim}
+%\begin{mpost*}[mpsettings{u:=\mpdim{\unitlength}}]
+%\end{verbatim}
+% you'll be able to use in the \MP{} code the variable $u$ which will be
+% set to the current \cmdname{unitlength} (don't say \texttt{save u;} in
+% the \MP{} code, of course).
+%
+% The \texttt{mpost*} environment \emph{can} go inside the argument
+% to a command.
+%
+%
+% \section{\XeLaTeX{} and \textsf{gmp}}
+%
+% The present package is compatible with \XeLaTeX{}; in this case it
+% performs also a conversion to \textsc{pdf} of the \textsc{mps} file
+% for inclusion. There are some limitations, though: it's impossible to
+% typeset labels to pictures with system fonts, as it would be in the
+% main document. Indeed \MP{} can't use \XeTeX{} for typesetting the
+% labels, only \LaTeX{}; this limitation is in \MP{}, we hope that in
+% the future it will be removed. If your main font is Linux Libertine,
+% for instance, you can typeset labels by saying
+%\begin{verbatim}
+%\usempxpackage[utf8]{inputenc}
+%\usempxpackage{libertine}
+%\end{verbatim}
+% (possibly passing some option to the latter package). Many fonts that
+% you can use with \XeLaTeX{} can also be used in \LaTeX{}, of course
+% without access to the full character set.
+%
+%
+% \section{Examples}
+%
+% Let's try some weird input with foreign characters.
+%\begin{verbatim}
+%\usepackage[latin1]{inputenc}
+%...
+%\usempxpackage[latin1]{inputenc}
+%...
+%\begin{center}
+%\begin{mpost}[mpxprogram=latex]
+%label(\btex àèü etex, origin);
+%draw fullcircle xscaled 1.5cm yscaled 2\mpdim\baselineskip;
+%\end{mpost}
+%\end{center}
+%\end{verbatim}
+% \begin{center}
+% \usempxpackage[latin1]{inputenc}
+% \begin{mpost}[mpxprogram=latex]
+% label(\btex àèü etex, origin);
+% draw fullcircle xscaled 1.5cm yscaled 2\mpdim\baselineskip;
+% \end{mpost}
+% \end{center}
+% Always use the same option to \textsf{inputenc} as your main
+% file or, if you are working with \XeLaTeX{}, 
+%\begin{verbatim}
+%\usempxpackage[utf8]{inputenc}
+%\end{verbatim}
+% in your document's preamble. Also \texttt{utf8x} is acceptable, of
+% course, in this case.
+%
+% Let's see instead a case where expansion in a \texttt{btex...etex}
+% construction is needed: we want to enclose numbers, colored in white,
+% inside an elliptical gray background.  The vertical axis of the
+% ellipse should be as high as the baseline skip and it should be a
+% circle if the number has only one digit; the additional problem is
+% that the number can be given as the representation of some counter
+% (for example \texttt{enumi}, a possible application is evident).
+%\begin{verbatim}
+%\newcounter{mycount}
+%\newlength{\mylen}
+%\newcommand{\circleit}[2][]{\settowidth{\mylen}{#2}%
+%  \begin{mpost}[mpxprogram=latex]
+%    fill fullcircle 
+%      xscaled max(\mpdim{\mylen+6pt},\mpdim{\baselineskip})
+%      yscaled \mpdim{\baselineskip}
+%      withcolor .4white;
+%    draw thelabel(btex \unexpanded{#1}#2 etex, origin)
+%      withcolor white;
+%  \end{mpost}}
+%
+%\circleit{\themycount}\quad
+%\setcounter{mycount}{3}\circleit{\themycount}\quad
+%\setcounter{mycount}{12}\circleit{\themycount}\quad
+%\renewcommand{\themycount}{\roman{mycount}}%
+%\circleit{\themycount}\quad
+%\circleit{44}\quad
+%\renewcommand{\themycount}{\arabic{mycount}}%
+%\circleit[\sffamily]{\themycount}
+%\end{verbatim}
+% \begin{center}
+% \newcounter{mycount}
+% \newlength{\mylen}
+% \newcommand{\circleit}[2][]{\settowidth{\mylen}{#2}%
+%   \begin{mpost}[mpxprogram=latex]
+%     fill fullcircle 
+%       xscaled max(\mpdim{\mylen+6pt},\mpdim{\baselineskip})
+%       yscaled \mpdim{\baselineskip}
+%       withcolor .4white;
+%     draw thelabel(btex \unexpanded{#1}#2 etex, origin)
+%       withcolor white;
+%   \end{mpost}}
+% \circleit{\themycount}\quad
+% \setcounter{mycount}{3}\circleit{\themycount}\quad
+% \setcounter{mycount}{12}\circleit{\themycount}\quad
+% \renewcommand{\themycount}{\roman{mycount}}%
+% \circleit{\themycount}\quad
+% \circleit{44}\quad
+% \renewcommand{\themycount}{\arabic{mycount}}%
+% \circleit[\sffamily]{\themycount}
+% \end{center}
+%
+% In this case we \emph{want} that what is inside \texttt{btex...etex}
+% is expanded, in case it is \cmdname{themycount}.  Of course we have to
+% be sure that the expansion of the command consists only of 
+% characters. So, for example,
+%\begin{verbatim}
+%\renewcommand{\themycount}{\textsf{\arabic{mycount}}}
+%\end{verbatim}
+% would not work for the last example.  This is the reason for having
+% defined an optional argument to \cmdname{circleit}.  The trick of
+% using this argument in \cmdname{unexpanded} keeps every program happy
+% and the label is typeset correctly.  More fun for the \TeX{}ackers!
+%
+%
+% \section{Conversion from \textsf{emp}}
+%
+% It's quite easy to convert old files that use \textsf{emp} without
+% changing too much; a typical \texttt{emp} environment is
+%\begin{verbatim}
+%\begin{emp}[xyz](15,30)
+%...;
+%\end{emp}
+%\end{verbatim}
+% where the dots stand for \MP{} statements and \texttt{xyz} is the name
+% for subsequent use. This may be transformed into
+%\begin{verbatim}
+%\begin{mpost}[name=xyz,use]
+%w:=\mpdim{15\unitlength};
+%h:=\mpdim{30\unitlength};
+%...;
+%\end{mpost}
+%\end{verbatim}
+% An \texttt{empgraph} environment such as
+%\begin{verbatim}
+%\begin{empgraph}[xyz](15,30)
+%...;
+%\end{empgraph}
+%\end{verbatim}
+% must be transformed into
+%\begin{verbatim}
+%\begin{mpost}[name=xyz,use](15,30)
+%w:=\mpdim{15\unitlength};
+%h:=\mpdim{30\unitlength};
+%draw begingraph(w,h);
+%...;
+%endgraph;
+%\end{mpost}
+%\end{verbatim}
+% Remember to change all \texttt{btex} into \texttt{\string\btex} and
+% the auxiliary commands into the similar ones of \textsf{gmp}: it
+% should be almost straightforward. If people ask for it, I might add a
+% compatibility layer for \textsf{emp}.
+%
+% Alternatively, the first case might be treated as
+%\begin{verbatim}
+%\begin{mpost*}[name=xyz,
+%  mpsettings={w:=\mpdim{15\unitlength};
+%    h:=\mpdim{30\unitlength};}]
+%...;
+%\end{mpost*}
+%\end{verbatim}
+% You might prefer this strategy if you have many \texttt{btex...etex}
+% pairs. Look out for \cmdname{end} commands, though: if not properly
+% braced, they will confuse the processing of the environment's content.
+%
+% \StopEventually{
+% \begin{thebibliography}{1}
+%
+% \bibitem{hagen-metafun}%
+% Hans Hagen, Metafun,
+% \url{http://www.pragma-ade.nl/general/manuals/metafun-p.pdf}
+%
+% \bibitem{hoenig}%
+% Alan Hoenig, \emph{\TeX{} unbound}, Oxford University Press, Oxford
+% and New York, 1998.
+%
+% \bibitem{peter2005}%
+% Steve Peter, ``\cmdname{starttext}, Swelled Rules and \MP{}'', The 
+% Prac\TeX{} Journal, n.~4 (2005).
+%
+% \end{thebibliography}
+% }
+%
+% \section{Implementation}
+%
+% Before doing anything, we check that the engine knows about
+% |\unexpanded| and |\dimexpr|; otherwise we say good-bye.
+%    \begin{macrocode}
+\@ifundefined{eTeXversion}{%
+  \PackageError{gmp}{This package requires a e-TeX extensions}
+    {The gmp package requires a modern TeX engine, please upgrade}%
+  \endinput}{}
+%    \end{macrocode}
+% We need \textsf{xkeyval} for its key-value interface. Then we define
+% some conditional for later usage and the package options.
+%    \begin{macrocode}
+\RequirePackage{xkeyval}[2005/01/30]
+
+\newif\ifgmp@latex % true if always using latex for mpx
+\newif\ifgmp@locallatex % true if using latex for mpx for a 
+                        % single figure
+
+\newif\ifgmp@nogen % true if we are not generating the mps files
+\newif\ifgmp@nowrite % true if we are not writing the mp files
+\newif\ifgmp@warn % true if we are issuing the final message
+
+\DeclareOptionX<ggmp>{tex}{\def\gmp@mpxprogram{tex}%
+  \gmp@latexfalse\gmp@locallatexfalse}
+\DeclareOptionX<ggmp>{latex}{\def\gmp@mpxprogram{latex}%
+  \gmp@latextrue\gmp@locallatextrue}
+
+\DeclareOptionX<ggmp>{noshellescape}{\gmp@nogentrue}
+\DeclareOptionX<ggmp>{shellescape}{\gmp@nogenfalse}
+
+\DeclareOptionX<ggmp>{nowrite}{\gmp@nowritetrue}
+\DeclareOptionX<ggmp>{write}{\gmp@nowritefalse}
+
+\DeclareOptionX<ggmp>{envname}{\def\gmp@envname{#1}}
+\DeclareOptionX<ggmp>{extension}{\def\gmp@ext{#1}}
+
+\def\gmp@preoptions{}
+\DeclareOptionX<ggmp>{everymp}{\edef\gmp@preoptions{\gmp@preoptions^^J#1}}
+
+\DeclareOptionX<ggmp>{clean}{\def\gmp@clean{#1}}
+
+\DeclareOptionX<ggmp>{rmcommand}{\def\gmp@remove{#1}}
+\DeclareOptionX<ggmp>{postrmcommand}{\def\gmp@postremove{#1}}
+
+\def\gmp@jobname{\jobname}
+%    \end{macrocode}
+% Now we set the default options: the mpx program is \TeX{}; we write
+% out the auxiliary files and do not assume shell-escape; no cleaning
+% after compilation of the \MP{} files; default environment names are
+% \texttt{mpost} and \texttt{mpost*}; default mp-extension is
+% \texttt{+mp}. Then we read the package options.
+%    \begin{macrocode}
+\ExecuteOptionsX<ggmp>{tex,noshellescape,write,clean=none}
+\ExecuteOptionsX<ggmp>{envname=mpost,extension=+mp,
+  rmcommand=rm -f,postrmcommand={}}
+\ProcessOptionsX<ggmp>\relax
+%    \end{macrocode}
+% We need some auxiliary packages, they'll probably be loaded anyway,
+% with the exception of \textsf{environ} that's employed for the
+% \texttt{mpost*} environment, but has no known incompatibility.
+%    \begin{macrocode}
+\RequirePackage{graphicx}
+\RequirePackage{ifpdf}
+\RequirePackage{ifxetex}
+\RequirePackage{environ}
+%    \end{macrocode}
+% With \XeLaTeX{} we need to run epstopdf; we don't support
+% Lua\LaTeX{}, because looking at shell-escape is useless, at the
+% moment, even via Heiko Oberdiek's \textsf{pdftexcmds} (at least for
+% the time being).
+%    \begin{macrocode}
+\ifxetex
+  \let\gmp@shellescape\shellescape
+  \def\gmp@preoptions{prologues:=3;^^J}
+\else
+  \ifdefined\pdfshellescape % (pdf)latex
+    \let\gmp@shellescape\pdfshellescape
+  \else % lualatex
+    \chardef\gmp@shellescape=\z@
+    \gmp@nogentrue
+  \fi
+\fi
+%    \end{macrocode}
+% We define some warning messages; in some cases the message enables
+% or disables other messages.
+%    \begin{macrocode}
+\def\gmp@msgdisallowed{\PackageWarningNoLine{gmp}{Compilation and
+  writing of MetaPost files has been\MessageBreak disallowed by the
+  `nowrite' option}\gdef\gmp@nemessage{}}
+\def\gmp@msgnonexistent{\PackageWarning{gmp}{Non existent MetaPost
+  file requested}\ifgmp@warn\else\global\gmp@warntrue\fi}
+\def\gmp@msgrequestx{\PackageWarningNoLine{gmp}{The MetaPost file you
+  requested does not exist,\MessageBreak perhaps by a compilation
+  error}}
+\def\gmp@msgremember{\PackageWarningNoLine{gmp}{Remember to run `sh
+  \gmp@jobname\gmp@ext.sh' and rerun (pdf)LaTeX}}
+%    \end{macrocode}
+% The following lines are to avoid spurious messages, opening and 
+% writing of files if the user has not activated the shell escape 
+% feature but has given the shell-escape option.
+%    \begin{macrocode}
+\def\gmp@msgensure{%
+  \PackageWarningNoLine{gmp}{Ensure that you have enabled the shell
+    escape feature, or\MessageBreak you can be in trouble. The 
+    available MetaPost generated\MessageBreak files will be used
+    anyway. Use option `nowrite' if they\MessageBreak are already
+    in final form}%
+  \let\gmp@message\@gobble
+  \let\gmp@writexviii\@gobble
+  \def\gmp@openout##1##2\@nil{}%
+  \let\gmp@write\@gobbletwo
+  \let\gmp@closeout\@gobble}
+%    \end{macrocode}
+% Now we define some abbreviations for primitive actions, so that we
+% are able to change their meaning at will.
+%    \begin{macrocode}
+\let\gmp@message\message
+\def\gmp@writexviii{\immediate\write18 }
+\def\gmp@openout#1#2\@nil{\immediate\openout#1#2}
+\def\gmp@write{\immediate\write}
+\def\gmp@closeout{\immediate\closeout}
+%    \end{macrocode}
+% \begin{macro}{\gmp@command}
+% Here we define the main internal macro, |\gmp@command|, which has
+% different definitions depending on the package options. If the
+% \texttt{nowrite} option is valid, there's even no need for it;
+% otherwise it must behave differently: if we are doing immediate
+% compilation via shell-escape it must act by emitting
+% |\gmp@writexviii|, otherwise it must write the command in the batch
+% file to be run after the \LaTeX{} run. In the latter case we also
+% open an output stream and write a prologue on it.
+%    \begin{macrocode}
+\def\gmp@setupmacros{%
+\ifgmp@nowrite
+  \let\gmp@nemessage\gmp@msgdisallowed
+\else
+  \ifgmp@nogen
+    \let\gmp@nemessage\gmp@msgnonexistent
+    \def\gmp@command{%
+        mpost \ifx\gmp@mpmem\empty\else\space\gmp@mpmem\space\fi}%
+    \newwrite\gmp@shellout
+    \immediate\openout\gmp@shellout=\gmp@jobname\gmp@ext.sh%
+    \immediate\write\gmp@shellout{\string##!/bin/sh}%
+    \def\gmp@shellcommand##1{\immediate\write\gmp@shellout{##1}}%
+    \AtEndDocument{\ifgmp@warn\gmp@msgremember\gmp@warnfalse\fi}%
+  \else
+    \let\gmp@nemessage\gmp@msgrequestx
+    \ifnum\gmp@shellescape=\@ne
+      \def\gmp@command{%
+        mpost -interaction=nonstopmode %
+        \ifx\gmp@mpmem\empty\else\space\gmp@mpmem\space\fi}%
+      \def\gmp@shellcommand##1{%
+        \gmp@message{^^J(gmp) Doing external command^^J(gmp) \string"}%
+        \gmp@writexviii{echo ##1'\string"'}\gmp@writexviii{##1}%
+      }%
+    \else
+      \gmp@msgensure\let\gmp@shellcommand\@gobble
+    \fi
+  \fi
+\fi
+}
+\gmp@setupmacros
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\gmpoptions}
+% Next we define |\gmpoptions| which can be used to set package
+% options in a more friendly way. However we disallow it outside the
+% preamble, because otherwise the status of the macros would not be
+% predictable.
+%    \begin{macrocode}
+\def\gmpoptions#1{\setkeys{ggmp}{#1}\gmp@setupmacros}
+\@onlypreamble\gmpoptions
+%    \end{macrocode}
+% \end{macro}
+% We next define a standard \LaTeX{} preamble for mpx.
+%    \begin{macrocode}
+\def\gmp@latexpreamble{%^^J%
+  \gmp@percent\string&latex^^J%
+  \string\documentclass[1\@ptsize pt]{article}^^J%
+  \ifx\empty\gmp@packages\else\the\gmp@packages^^J\fi%
+  \ifx\empty\gmp@commands\else\the\gmp@commands^^J\fi%
+  \string\begin{document}^^J}
+%    \end{macrocode}
+% \begin{macro}{\usempxclass}\begin{macro}{\usempxpackage}
+% If one wants a non standard \LaTeX{} class, the command
+% |\usempxclass|, with the same syntax as |\documentclass|, is
+% provided. Similarly for |\usempxpackage|; |\resetmpxpackages| clears
+% out the loading of packages.
+%    \begin{macrocode}
+\newcommand\usempxclass[2][]{%
+  \def\gmp@latexpreamble{^^J%
+    \gmp@percent\string&latex^^J%
+    \string\documentclass[#1]{#2}^^J%
+    \ifx\empty\gmp@packages\else\the\gmp@packages^^J\fi%
+    \ifx\empty\gmp@commands\else\the\gmp@commands^^J\fi%
+    \string\begin{document}^^J}}
+\newtoks\gmp@packages
+\newcommand\usempxpackage[2][]{%
+  \gmp@packages=\expandafter{\the\gmp@packages^^J%
+    \usepackage[#1]{#2}}}
+\newcommand\resetmpxpackages{\gmp@packages={}}
+%    \end{macrocode}
+% \end{macro}\end{macro}
+% \begin{macro}{\mpxcommands}
+% With |\mpxcommands| one can insert definitions to be used for \MP{}
+% label composition: these are seen only if \LaTeX{} is used for
+% mpx. There's also |\resetmpxcommands| in case of need.
+%    \begin{macrocode}
+\newtoks\gmp@commands
+\newcommand\mpxcommands[1]{%
+  \gmp@commands=\expandafter{\the\gmp@commands^^J%
+    #1}}
+\newcommand\resetmpxcommands{\gmp@commands={}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\mpdim}
+% The |\mpdim| macro is used in the \texttt{mpost} environment or in
+% the value of the key \texttt{mpsettings} for passing length
+% depending on current conditions. We exploit |\dimexpr| that strips
+% out possible `elastic' components and allows for doing
+% calculations. The result is written out surrounded by
+% \texttt{begingroup} and \texttt{endgroup} that make the number
+% obtained look like a variable at \MP's eyes.
+%    \begin{macrocode}
+\def\mpdim#1{ begingroup \the\dimexpr#1\relax\space endgroup }
+%    \end{macrocode}
+% \end{macro}
+% Now we start the hard task of writing out the auxiliary files. So we
+% define an output stream and a counter that keeps track of the figure
+% names; in order to know the total number of the pictures, at
+% end-of-document we define an internal label which is currently
+% unused, though.
+%    \begin{macrocode}
+\newwrite\gmp@out
+\newcounter{gmp@count}
+\AtEndDocument{%
+  \refstepcounter{gmp@count}%
+  \label{gmp@finallabel}%
+}
+%    \end{macrocode}
+% \begin{environment}{mpost}
+% The \texttt{mpost} environment (but the name can be set at package
+% loading) must read the `local options' given as an optional argument
+% as the usual list of key-value statements. First of all it must step
+% the \MP{} figure counter and set a label for it for subsequent
+% calling of the graphics, then we grab the option given to the
+% environment.
+%    \begin{macrocode}
+\newenvironment{\gmp@envname}[1][]
+  {\@bsphack
+   \global\gmp@usefalse
+   \refstepcounter{gmp@count}\label{gmp@label@\thegmp@count}%
+   \bgroup
+   \edef\gmp@number{\thegmp@count}%
+   \gmp@grab{#1}}
+  {\@esphack}
+%    \end{macrocode}
+% \end{environment}
+% \begin{environment}{mpost*}
+% The \texttt{mpost*} environment writes out its contents without
+% \TeX{} macro expansion; we simply use \texttt{mpost}: so we gather
+% the optional argument into a scratch token register, collect the
+% body of the environment and pass it to the |\gmp@writeunex| macro
+% which calls |\begin{mpost}| (possibly with the name chosen by the
+% user), to which are passed the options. The first |\unexpanded| is
+% removed by |\edef|, the second one by the writing process.
+%    \begin{macrocode}
+\def\gmp@writeunex#1{\begingroup
+  \edef\x{\endgroup\noexpand\begin{\gmp@envname}[\the\toks@]%
+    \unexpanded{\unexpanded{#1}}\noexpand\end{\gmp@envname}}\x}
+\newenvironment{\gmp@envname*}[1][]
+  {\toks@{#1}\Collect@Body\gmp@writeunex}{}
+%    \end{macrocode}
+% \end{environment}
+% Here we define the key-value interface for the options to the
+% environments, with some auxiliary macros and conditionals;
+% |\gmp@fourdigits| is used for the output file names, we think that
+% more than $9999$ pictures are difficult to be present for a single
+% file; but this will not limit at all the user's possibilities.
+%    \begin{macrocode}
+\def\gmp@fourdigits#1{%
+  \ifnum#1<10   0\fi
+  \ifnum#1<100  0\fi
+  \ifnum#1<1000 0\fi\number #1}
+\def\gmp@not@a@name@{@not@a@name@}
+\def\gmp@choosetex{\gmp@locallatexfalse}
+\def\gmp@chooselatex{\gmp@locallatextrue}
+\def\gmp@doiflatex#1{\ifgmp@latex#1\else\ifgmp@locallatex#1\fi\fi}
+\def\gmp@mpmem{}
+\newif\ifgmp@use
+\define@key{gmp}{name}[@not@a@name@]{%
+  \def\gmp@thisname{#1}%
+  \expandafter\xdef\csname gmp@fig#1\endcsname
+    {\gmp@fourdigits{\gmp@number}}}
+\define@key{gmp}{use}[true]{\global\csname gmp@use#1\endcsname}
+\define@key{gmp}{mpmem}{\def\gmp@mpmem{-mem #1}}
+\define@key{gmp}{mpsettings}{\edef\gmp@preoptions{\gmp@preoptions^^J#1}}
+\define@key{gmp}{mpxcommands}{%
+  \gmp@commands=\expandafter{\the\gmp@commands^^J#1}}
+\define@key{gmp}{mpxprogram}{%
+  \def\gmp@mpxprogram{#1}%
+  \csname gmp@choose#1\endcsname}
+\define@key{gmp}{runs}{\chardef\gmp@runs=#1\relax}
+%    \end{macrocode}
+% \begin{macro}{\gmp@grab}
+% The |\gmp@grab| macro sets the value of the keys; the \texttt{name}
+% must be initially empty and the number of runs should be~$1$. The
+% conditional |\if@gmpuse| is set to false at the beginning of the
+% environment, and to true when \texttt{use} is given or when there's
+% no name. Finally the macro calls |\gmp@innermpost|.
+%    \begin{macrocode}
+\def\gmp@grab#1{%
+  \setkeys{gmp}{name}%
+  \setkeys{gmp}{runs=1}%
+  \setkeys{gmp}{#1}%
+  \ifx\gmp@thisname\gmp@not@a@name@
+    \global\gmp@usetrue
+  \fi
+  \gmp@setup\gmp@innermpost}
+%    \end{macrocode}
+% \end{macro}
+% Before defining the macro responsible for the task of writing out
+% the \MP{} files, we do some housekeeping.
+%
+% We ensure that the character we need are written correctly in the
+% \MP{} files; so we define a `printing' percent sign and change the
+% category code of characters that might be made active by
+% \textsf{babel} or other packages. The semicolon is made active: it
+% will output a semicolon followed by a new line character; in the
+% environment |\par| means `go to a new line', so that empty lines in
+% a \texttt{mpost} environment will cause a new line in the output
+% file. However this doesn't work currently for \texttt{mpost}
+% environments given as arguments to other commands; since the normal
+% buffer size is around $50\,000$, this should not be a problem.
+%    \begin{macrocode}
+\begingroup\@makeother\%\def\x{\endgroup\def\gmp@percent{%}}\x
+\def\gmp@activesc{\catcode`\;=\active
+  \begingroup\lccode`\~=`\;
+  \lowercase{\endgroup\edef~}{\string;^^J}}
+\def\gmp@otherchars{\do\!\do\=\do\:\do\"\do\?\do\'\do\`\do\|}
+%    \end{macrocode}
+% \begin{macro}{\gmp@setup}
+% The following macro |\gmp@setup| starts writing the output files,
+% after setting category codes and something else; it doesn't write
+% anything if the option \texttt{nowrite} is in force, otherwise
+% writes a prologue and all needed preliminaries, up to
+% \texttt{beginfig(}\meta{number}\texttt{)}; this number is actually
+% irrelevant, because we use \texttt{outputtemplate}, but it should
+% correspond to the number appearing in the name of the output file.
+%    \begin{macrocode}
+\def\gmp@setup{%
+  \let\do\@makeother\gmp@otherchars\newlinechar=`\^^J
+  \gmp@activesc
+  \def\par{^^J}%
+  \ifgmp@nowrite\else
+    \edef\@temp{\gmp@jobname\gmp@ext\gmp@fourdigits{\gmp@number}.mp}%
+    \expandafter\gmp@openout\expandafter\gmp@out\@temp\@nil
+    \gmp@write\gmp@out{%
+      \gmp@percent\gmp@percent\space
+        Do not edit, this file has been generated^^J%
+      \gmp@percent\gmp@percent\space
+        automatically by \jobname.tex via gmp.sty^^J^^J%
+      \gmp@doiflatex{verbatimtex\gmp@latexpreamble etex;^^J}%
+      \ifx\empty\gmp@preoptions\else\gmp@preoptions^^J\fi%
+      outputtemplate:= "\gmp@percent j.mps";^^J%
+      beginfig(\gmp@number);%^^J%
+    }%
+  \fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\gmp@innermpost}
+% This is the central macro which collects the body of the
+% environment; we chose to use |\end| as delimiter so that the
+% environment can be used inside other arguments or definitions; maybe
+% it's not the best way to do this, but other than requiring
+% protection of |\end| commands inside the environment seems to have
+% no side effects. The environment's content is written out to the
+% \MP{} file, followed by \texttt{endfig;} and \texttt{end}; if
+% \LaTeX{} is used for the labels, also the closing statements are
+% added (though they are not strictly necessary). Then
+% |\gmp@shellcommand| is performed one or more times according to the
+% value of \texttt{runs}. It will run \MP{} stopping \LaTeX{}
+% momentarily or write the command to the shell script, according to
+% the current package options. In the case of \XeLaTeX{} it will also
+% call or write for a run of \textsf{epstopdf}. Finally, it executes
+% |\end{mpost}| and uses the object if it has been requested to do,
+% that is, if |\ifgmp@use| is true.
+%    \begin{macrocode}
+\long\def\gmp@innermpost#1\end#2{%
+  \ifgmp@nowrite\else
+    \gmp@write\gmp@out{%
+      #1^^Jendfig;^^Jend.%
+      \gmp@doiflatex{^^Jverbatimtex^^J\string\end{document}^^Jetex}}%
+    \gmp@closeout\gmp@out
+    \count@=\gmp@runs
+    \loop\ifnum\count@>\z@
+      \gmp@shellcommand{\gmp@command\space 
+        -tex=\gmp@mpxprogram\space\gmp@jobname\gmp@ext
+        \gmp@fourdigits{\gmp@number}}%
+    \advance\count@\m@ne
+    \repeat
+    \ifxetex
+      \gmp@shellcommand{epstopdf --hires \gmp@jobname\gmp@ext
+        \gmp@fourdigits{\gmp@number}.mps}%
+    \fi
+  \fi
+  \egroup
+  \end{#2}\ifgmp@use
+  \gmp@usempost{\thegmp@count}\fi}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\usempost}
+% The macros for using the compiled pictures are almost straightforward:
+% the files will have extension \texttt{.mps} for \LaTeX{} or
+% \textsc{pdf}\LaTeX{} and \texttt{.pdf} for \XeLaTeX{}. We check that
+% they exist and load them or issue a warning.
+%    \begin{macrocode}
+\ifxetex
+  \def\gmp@usempost#1{%
+    \edef\gmp@thempsfile{\gmp@jobname\gmp@ext\gmp@fourdigits{#1}}%
+    \IfFileExists{\gmp@thempsfile.pdf}%
+    {\includegraphics{\gmp@thempsfile.pdf}}%
+    {\gmp@nemessage\gmp@box}}
+  \newcommand\usempost[2][]{%
+    \IfFileExists{\gmp@jobname\gmp@ext\csname gmp@fig#2\endcsname.pdf}%
+    {\includegraphics[#1]
+      {\gmp@jobname\gmp@ext\csname gmp@fig#2\endcsname.pdf}}%
+    {\gmp@nemessage\gmp@box}}
+\else
+  \def\gmp@usempost#1{%
+    \edef\gmp@thempsfile{\gmp@jobname\gmp@ext\gmp@fourdigits{#1}}%
+    \IfFileExists{\gmp@thempsfile.mps}%
+    {\includegraphics[hiresbb]{\gmp@thempsfile.mps}}%
+    {\gmp@nemessage\gmp@box}}
+\newcommand\usempost[2][]{%
+  \IfFileExists{\gmp@jobname\gmp@ext\csname gmp@fig#2\endcsname.mps}%
+  {\includegraphics[hiresbb,#1]
+    {\gmp@jobname\gmp@ext\csname gmp@fig#2\endcsname.mps}}%
+  {\gmp@nemessage\gmp@box}}
+\fi
+\def\gmp@box{\fbox{\@ifundefined{color}{}{\color{red}}MP}}
+%    \end{macrocode}
+% \end{macro}
+% Now we clean up our directory from the auxiliary files, at the
+% user's request, of course. The \texttt{clean} keyword may be
+% specified in the package options or in |\gmpoptions| to have a value
+% among |none|, |aux|, or |mp|.
+%
+% At end document we look at the value of this key and do what's
+% desired by the user. If the value is not recognized we issue a
+% warning and act as if |clean=none| had been given; otherwise we
+% execute the requested command or write them in the batch script.
+%    \begin{macrocode}
+\AtEndDocument{%
+  \@ifundefined{gmp@doclean@\gmp@clean}
+    {\expandafter\gmp@badcleaning\expandafter{\gmp@clean}}
+    {\@nameuse{gmp@doclean@\gmp@clean}}}
+\def\gmp@badcleaning#1{\PackageWarningNoLine{gmp}{%
+  Wrong cleaning option `clean=#1'; `clean=none' used}}
+\def\gmp@doclean@none{}
+\def\gmp@doclean@aux{%
+  \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.log\space\gmp@postremove}%
+  \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.mpx\space\gmp@postremove}%
+  \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.mpo\space\gmp@postremove}%
+    }
+\def\gmp@doclean@mp{%
+  \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.log\space\gmp@postremove}%
+  \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.mpx\space\gmp@postremove}%
+  \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.mpo\space\gmp@postremove}%
+  \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.mp\space\gmp@postremove}%
+  \ifxetex
+    \gmp@shellcommand{\gmp@remove\space
+    \jobname\gmp@ext*.mps\space\gmp@postremove}%
+  \fi}
+%    \end{macrocode}
+% \begin{macro}{\verbatimtex}\begin{macro}{\btex}
+% Final definition for not expanding macros in the \MP{} labels.
+%    \begin{macrocode}
+\long\def\verbatimtex#1etex{verbatimtex \unexpanded{#1} etex}
+\long\def\btex#1etex{btex \unexpanded{#1} etex}
+%    \end{macrocode}
+% \end{macro}\end{macro}
+% \Finale
+\endinput
+
+% Local Variables: 
+% mode: doctex
+% coding: latin-1
+% End: 
diff --git a/Master/texmf-dist/source/latex/gmp/gmp.ins b/Master/texmf-dist/source/latex/gmp/gmp.ins
new file mode 100644
index 00000000000..6001574f9f9
--- /dev/null
+++ b/Master/texmf-dist/source/latex/gmp/gmp.ins
@@ -0,0 +1,71 @@
+% Copyright (C) 2011 by Enrico Gregorio 
+% <Enrico dot Gregorio at univr dot it>
+% -------------------------------------------------------
+% 
+% This work may be distributed and/or modified under the
+% conditions of the LaTeX Project Public License, either
+% version 1.3c 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 2005/12/01 or later.
+%
+% This work has the LPPL maintenance status `maintained'.
+% 
+% The Current Maintainer of this work is Enrico Gregorio.
+%
+% This work consists of the files
+%   gmp.dtx 
+%   gmp.ins
+% and the derived file gmp.sty.
+
+\input docstrip.tex
+\keepsilent
+
+\usedir{tex/latex/gmp}
+
+\preamble
+
+This is a generated file.
+
+Copyright (C) 2011 by Enrico Gregorio 
+<Enrico dot Gregorio at univr dot it>
+-------------------------------------------------------
+
+This work may be distributed and/or modified under the
+conditions of the LaTeX Project Public License, either
+version 1.3c 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 2005/12/01 or later.
+
+This work has the LPPL maintenance status `maintained'.
+
+The Current Maintainer of this work is Enrico Gregorio.
+
+This work consists of the files
+  gmp.dtx 
+  gmp.ins
+and the derived file gmp.sty.
+
+\endpreamble
+
+\generate{\file{gmp.sty}{\from{gmp.dtx}{package}}}
+
+\obeyspaces
+\Msg{*************************************************************}
+\Msg{*                                                           *}
+\Msg{* To finish the installation you have to move the following *}
+\Msg{* file into a directory searched by TeX:                    *}
+\Msg{*                                                           *}
+\Msg{*     gmp.sty                                               *}
+\Msg{*                                                           *}
+\Msg{* To produce the documentation run the file                 *}
+\Msg{* gmp.dtx through LaTeX.                                    *}
+\Msg{*                                                           *}
+\Msg{* Happy TeXing!                                             *}
+\Msg{*                                                           *}
+\Msg{*************************************************************}
+
+\endbatchfile