halloweenmath (6jan17)

git-svn-id: svn://tug.org/texlive/trunk@42887 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 2078 insertions, 0 deletions

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+% \iffalse
+%   (This is a META-COMMENT.)
+%
+%   This is file `halloweenmath.dtx'.
+%
+%   This file is part of a work named "halloweenmath package".
+%
+%   Copyright (C) 2017 by Gustavo MEZZETTI.
+%
+%   This file may be distributed and/or modified under the conditions
+%   of the LaTeX Project Public License, either version 1.3 of this
+%   license or (at your option) any later version.
+%   The latest version of this license is in
+%     http://www.latex-project.org/lppl.txt
+%   and version 1.3 or later is part of all distributions of LaTeX
+%   version 2005/12/01 or later.
+%
+%   The halloweenmath package has the LPPL maintenance status
+%     "author-maintained".
+%
+%   The file `manifest.txt' that comes along with this file specifies what the
+%   halloweenmath package consists of; more precisely, it explains how the
+%   locutions "Work" and "Compiled Work", used in the LaTeX Project Public
+%   License, are to be interpreted in the case of this work.
+%
+%   Note that the distribution of this file alone is "distribution of
+%   only part of the Work" in the sense of the LaTeX Project Public
+%   License, and should be avoided (see the LaTeX Project Public
+%   Licence for details).
+%
+%   (End of the META-COMMENT.)
+% \fi
+%
+% \def\filename{halloweenmath.dtx}
+% \def\fileversion{0.01}
+% \def\filedate{2017/01/06}
+% \def\docdate {2017/01/06}
+% \def\doclongdate{January~6, 2017}
+%
+% ^^A \CheckSum{13}
+%
+% \changes{0.01}{2017 Jan 06}{First writing of the code}
+%
+%% \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         \~}
+%
+% \MakeShortVerb{\"}
+% \DeleteShortVerb{\|}
+%
+% \DoNotIndex{\begin,\end,\def,\let,\else,\fi,\@ifdefinable,\@empty}
+% \DoNotIndex{\newcommand,\renewcommand}
+% \DoNotIndex{\newenvironment,\renewenvironment}
+% \DoNotIndex{\z@,\z@skip,\p@,\@ne,\tw@,\thr@@,\@m,\@M,\m@ne}
+% \DoNotIndex{\setlength,\setcounter,\addtolength}
+% \DoNotIndex{\expandafter,\do,\relax,\advance,\multiply,\divide}
+% \DoNotIndex{\DeclareOption,\ExecuteOptions,\ProcessOptions}
+% \DoNotIndex{\",\.,\@}
+%
+% \IndexPrologue{
+%   \section{\indexname}
+%   Numbers in italics refer to the page where the corresponding entry
+%   is described, the ones underlined to the code line of the
+%   definition, the rest to the code lines where the entry is used.
+% }
+% \setcounter{IndexColumns}{2}
+%
+% \GlossaryPrologue{\section{Change History}}
+%
+% \setcounter{StandardModuleDepth}{1}
+%
+% \setlength{\unitlength}{1cm}
+% \definecolor{guidelines}{rgb}{0,.5,1}
+% \definecolor{coverwitch}{rgb}{.1,.4,.5}
+%
+% \newcommand*{\DS}{\textsf{DocStrip}}
+% \newcommand*{\TikZ}{Ti\emph{k}Z}
+% \renewcommand*{\partname}{Part}
+% \newcommand*{\halloweenmath}{halloweenmath}
+% \newcommand*{\amsmath}{amsmath}
+% \newcommand*{\picttwoe}{pict2e}
+% \newcommand*{\textoken}[1]{\(\langle\mbox{\normalfont #1}\rangle\)}
+% \makeatletter
+% \newcommand*{\myspecialindex}[2]
+%    {\special@index{#1\actualchar#2\encapchar main}}
+% \newcommand*{\param}[1]{\(\mbox{\##1}\leftarrow{}\)\>}
+% \newenvironment*{paramlist}{^^A
+%   \@beginparpenalty \@M \relax
+%   \setlength\topsep{\z@}^^A
+%   \tabbing
+%   \(\mbox{\#0}\leftarrow {\,}\)\=\kill
+% }{^^A
+%   \endtabbing
+% }
+% \makeatother
+% \newcommand*{\counterindex}[1]{\myspecialindex{#1}{{\string\ttfamily
+%    \space #1} (counter)}\index{counters:\levelchar{\protect\ttfamily
+%    #1}\encapchar usage}}
+% \newcommand*{\optuseindex}[1]{\SortIndex{#1}{\protect\opt{#1}
+%    (option)\encapchar usage}\index{options:\levelchar
+%    \protect\opt{#1}\encapchar usage}}
+% \DeclareRobustCommand*{\packlass}[1]{{\normalfont\sffamily #1}}
+% \DeclareRobustCommand*{\filedir}[1]{{\normalfont\ttfamily #1}}
+% \DeclareRobustCommand*{\env}[1]{{\normalfont\ttfamily #1}}
+% \DeclareRobustCommand*{\ctr}[1]{{\normalfont\ttfamily #1}}
+% \DeclareRobustCommand*{\opt}[1]{{\normalfont\ttfamily #1}}
+% \newcommand*{\sopt}[1]{\mbox{\opt{#1}}\optuseindex{#1}}
+% \DeclareRobustCommand*{\TeXSXuser}[1]{{\normalfont\sffamily #1}}
+% \newcommand*{\cfr}{\TeXSXuser{cfr}}
+%
+% \providecommand*{\href}[3][]{#3}
+% \providecommand*{\pdfbookmark}[3][]{}
+% \providecommand*{\hypersetup}{}
+%
+% \newcommand*{\magicstar}[1]{^^A
+%   \begingroup
+%     \setlength\unitlength{#1\unitlength}^^A
+%     \begin{picture}(0,0)^^A
+%       \polygon*(0,1)(-.225,.309)(-.951,.309)(-.363,-.118)(-.588,-.809)^^A
+%               (0,-.382)(.588,-.809)(.363,-.118)(.951,.309)(.225,.309)^^A
+%     \end{picture}^^A
+%   \endgroup
+% }
+%
+%
+%
+% \title{
+%    The \packlass{\halloweenmath} package:\\
+%    scary and creepy math symbols\\
+%    with \texorpdfstring{\hologo{AmSLaTeX}}{AMS-LaTeX}\ 
+%    integration\thanks{This file has
+%    version~\fileversion, release date \filedate;
+%    last documentation update: \docdate.
+%    Copyright \copyright~2017 by G.~Mezzetti
+%    (see page~\pageref{S:Copy}).}
+% }
+% \author{G. Mezzetti}
+% \date{\doclongdate}
+%
+% \hypersetup{
+%   pdftitle        = {The halloweenmath package:
+%                       scary and creepy math symbols
+%                       with AMS-LaTeX integration},
+%   pdfauthor       = {G. Mezzetti},
+%   pdfsubject      = {Documentation of the halloweenmath package},
+%   pdfkeywords     = {Halloween, math, scary mathematical symbols},
+%   pdfcreationdate = {D:20170106000000},
+%   pdfmoddate      = {D:20170106000000},
+%   bookmarksopen,
+%   bookmarksopenlevel = 1
+% }
+%
+% \pdfbookmark[0]{Front Matter}{FrontMatter}
+% \maketitle
+%
+% \begin{abstract}
+%    This document describes a \LaTeX\ package that originates from a question
+%    asked for enjoyment on
+%    \href{http://tex.stackexchange.com/}{\emph{\TeX\,-\,\LaTeX\ Stack
+%    Exchange}} (see~\cite{bib:cfr}) by the user
+%    \href{http://tex.stackexchange.com/users/39222/cfr}{\cfr}; this package
+%    defines a handful of commands for typesetting mathematical symbols of
+%    various kinds (including ``large'' operators, extensible arrow-like
+%    relations, and growing arrow-like math accents) that all draw from the
+%    classic Halloween-related iconography (pumpkins, witches, ghosts, cats, and
+%    so on) while being, at the same time, seamlessly integrated within the rest
+%    of the mathematics produced by \hologo{LaTeX}\slash\hologo{AmSLaTeX}.
+% \end{abstract}
+%
+% \vfil
+%
+% \begin{center}
+%   \color{coverwitch}
+%   \begin{picture}(0,8)(0,-4)
+%     \roundcap
+%     \linethickness{4pt}
+%     \Line(-2,-2)(6,2)
+%     \linethickness{2pt}
+%     \Line(-2,-2)(-5,-2.5)
+%     \Line(-2,-2)(-4.85,-2.95)
+%     \Line(-2,-2)(-4.6,-3.3)
+%     \Line(-2,-2)(-4.35,-3.65)
+%     \Line(-2,-2)(-4,-4)
+%     \put(-3,-1.2){\magicstar{.4}}
+%     \put(-4.1,-.8){\magicstar{.8}}
+%     \put(-5.4,-1.8){\magicstar{.6}}
+%     \Line(0,1.8)(-.2,1.4)
+%     \polyline(.6,3.2)(.8,3)(1.5,3)
+%     \put(1.6,3){\oval(.2,.2)[tl]}
+%     \put(1.6,3){\oval(.2,.2)[r]}
+%     \polyline(1.6,2.9)(1.8,2.4)(1.2,2.4)(1,2.5)(1,2.3)
+%             (1.2,2)(1.6,1.8)(1.7,1.8)(1.7,1.6)(1.4,1.5)
+%             (0,1.8)(-.2,2)
+%     \Line(.2,2.8)(.6,3)
+%     \polygon*(-1,2)(-2,0)(-2,-1)(-1.5,-2)(1,-2)
+%             (0,-3.6)(.4,-3.8)(.6,-3.4)(.8,-4)(2,-4)
+%             (1,-3.6)(1,-3)(1.6,-3.2)(2,-1.5)(0,-1)
+%             (0,-.6)(1.4,-.6)(1.8,-.4)(2,0)(0,0)
+%             (0,1.4)
+%     \polygon*(-3,2)(-2.8,3)(-2,4)(-1.5,4.1)(-1,4)(0,3.5)
+%             (1,3.8)(2.5,3.5)(3,3.3)(2,3.4)(0,3)(-1,2)(-2,1.6)
+%             (-2.7,2)(-2,2)(-1,3)(-2,3.5)(-2.6,3)
+%     \linethickness{.4pt}
+%     \Line(1.7,1.6)(2,1.6)
+%     \Line(1.7,1.6)(1.9,1.4)
+%     \Line(1.7,1.6)(1.7,1.3)
+%     ^^A
+%     ^^A The cat:
+%     \put(3.6,1){\circle*{1.2}}
+%     \put(4.2,1.4){\circle*{1}}
+%     \put(4.5,2){\circle*{.8}}
+%     \polygon*(4.1,2)(4.1,2.5)(4.5,2.2)(4.9,2.5)(4.9,2)
+%     \linethickness{4pt}
+%     \cbezier(3.2,.6)(2,0)(4.2,-.4)(3,-1)
+%     \buttcap
+%     \linethickness{.4pt}
+%     \Line(3.8,2.1)(5.2,1.9)
+%     \Line(3.8,2)(5.2,2)
+%     \Line(3.8,1.9)(5.2,2.1)
+%   \end{picture}
+% \end{center}
+%
+% \newpage
+% \tableofcontents
+% \listoffigures
+%
+% \newpage
+% \begingroup
+%
+%    \setlength{\parskip}{\medskipamount}
+%    \setlength{\parindent}{0pt}
+%
+% \section*{Copyright notice}
+%    \label{S:Copy}
+%    \vspace{-\parskip}
+%
+%    Copyright \copyright~2017 by Gustavo \textsc{Mezzetti}.
+%    All rights are reserved, except as noted below.
+%
+%    This document has been produced by feeding to a \LaTeX\ typesetting engine
+%    the file \filedir{\filename} version \fileversion\ (\docdate).  This file
+%    is part of a work named ``\packlass{\halloweenmath} package'', and may be
+%    distributed and/or modified only as a part thereof.
+%    Subsection~\ref{sS:License} on page~\pageref{sS:License} explains the
+%    conditions under which the \packlass{\halloweenmath} package may be
+%    distributed and/or modified.
+%
+%    The \packlass{\halloweenmath} package has the following LPPL maintenance 
+%    status:\\
+%    ``author-maintained''.
+%
+%    Permission is granted to make new printed copies of this document, by any
+%    means (\emph{e.g.}, photocopying, direct printing from the electronic
+%    version, and so on).
+%
+%    Note, though, that distribution of this document alone is ``distribution of
+%    only part of the Work'' in the sense of the \LaTeX\ Project Public License,
+%    and should therefore be avoided: please distribute, in addition, the source
+%    file \filedir{\halloweenmath.dtx} together with all other files listed in
+%    \filedir{manifest.txt}, as explained as well in Subsection~\ref{sS:License}
+%    and in the file \filedir{manifest.txt} itself.
+%
+% \section*{Author's addresses}
+% \label{S:MyAddresses}
+%    \vspace{-\parskip}
+%
+%    The recommended way to contact the author is by e-mail; his address is:
+%
+%    \begin{list}{\setlength{\topsep}{0pt}}\item\relax
+%      gustavo dot mezzetti at istruzione dot it
+%    \end{list}
+%
+%    Please include the \emph{exact} phrase \verb*|halloweenmath package| in the
+%    \emph{subject} of your message; otherwise, your message could be
+%    thrown away by a mail filter.  In this regard, the weakness of the
+%    laws concerning the protection of privacy forces me to explicitly
+%    forbid the use of the above address for any kind of advertising,
+%    marketing, polling, or similar commercial or statistical contact.
+%
+%    If you have no e-mail access, write to:
+%
+%    \begin{list}{\setlength{\topsep}{0pt}}\item\relax
+%      Gustavo \textsc{Mezzetti}\\
+%      L.~S.~U. ``A.~di Savoia Duca degli Abruzzi''\\
+%      Via del Santo, 57\\
+%      I--35123\quad PADOVA\quad PD\\
+%      Italy
+%    \end{list}
+%
+% \endgroup
+%
+%
+%
+% \setcounter{secnumdepth}{0}
+%
+%
+%
+% \clearpage
+% \section{Introduction}
+%
+%    On October~31, 2016, around 3 in the morning (GMT\@), user
+%    \href{http://tex.stackexchange.com/users/39222/cfr}{\cfr} asked a
+%    question~\cite{bib:cfr} on the
+%    \href{http://tex.stackexchange.com/}{\emph{\TeX\,-\,\LaTeX\ Stack Exchange}
+%    network}, challenging other users to contribute \LaTeX\ documents that
+%    showcased ``the spookiest, creepiest images'' ever possible.  I~was aware
+%    of a method---well known, nonetheless---to integrate arbitrary pictures
+%    into math formulas as though they were mathematical symbols, so, on the
+%    pretext ``that, since \hologo{(La)TeX} is a language primarily designed to
+%    handle text with math, the lack of a `math-flavored'
+%    answer~\ldots\linebreak[0]\,was a gap that ought to be filled'', I~wrote an
+%    answer implementing a command that drew a (not particularly spooky or
+%    creepy) little witch astride of her broom, but with the silly distinctive
+%    feature of being seen by \LaTeX\ as a mathematical ``large'' operator like
+%    "\sum", "\prod", "\int", or "\bigcup"; this first command was named
+%    "\mathwitch" and was ``intended for denoting the operation of applying
+%    black magic to the ensuing subformula''.
+%
+%    I~subsequently added an extensible math accent similar to
+%    "\overrightarrow", but with the arrow replaced by a broom carrying the same
+%    witch and a black cat, and my answer ended up winning the contest (the
+%    presence of the cat turned out to be a decisive factor); besides, some
+%    users were so enthusiast of the new commands that they requested that they
+%    were re-implemented as a new, stand-alone package.  And here it is.
+%
+%    In the writing of the package, more features, and creatures, have been
+%    added.  Also available now are:
+%    \begin{itemize}
+%    \item
+%    ghosts, both still and hovering (or, if you prefer, acting both as ordinary
+%    symbols and as math accents similar to "\overrightarrow");
+%    \item
+%    a "\pumpkin" binary operator, with an associated ``large'' operator named
+%    "\bigpumpkin"\footnote{\cs{greatpumpkin} is available as a synonym, in
+%    homage to Linus van Pelt.} (cf.~"\cup" vs.\ "\bigcup", "\cap" vs.\
+%    "\bigcap", "\vee" vs.\ "\bigvee", "\oplus" vs.\ "\bigoplus",\,\ldots);
+%    \item
+%    extensible ``arrow-like'' brooms that act as relation symbols;
+%    \item
+%    clouds, for denoting unscrutable subformulas (this one is even sensible!);
+%    \item
+%    and still more.
+%    \end{itemize}
+%    All the above are available for the \texttt{bold} math version as well as 
+%    for the \texttt{normal} one.
+%    The symbols provided should prove sufficient for preparing lecture notes,
+%    slides, tests, or even exams to amuse~(?\@) your students with during the
+%    Halloween period.  Of course, any suggestion for additions and/or
+%    improvements are most welcome: you can find my addresses on
+%    page~\pageref{S:MyAddresses}.
+%
+%    As for the name of this new package, \cfr\ initially
+%    \href{http://tex.stackexchange.com/questions/336768/seasonal-challenge-contributions-from-texing-dead-welcome#comment828307_337719}{proposed}
+%    \packlass{mathwitch} (from the name of the main command);
+%    \href{http://tex.stackexchange.com/users/81905/guilherme-zanotelli}{\TeXSXuser{Guilherme
+%    Zanotelli}} then
+%    \href{http://tex.stackexchange.com/questions/336768/seasonal-challenge-contributions-from-texing-dead-welcome#comment828796_337719}{suggested}
+%    \packlass{mathemagics} (a truly befitting pun!); but in the end I~decided
+%    to choose \packlass{\halloweenmath} because (1)~it instantly and clearly
+%    communicates the context in which the package arose, as well as the purpose
+%    for which it was written, and (2)~it is 13~characters long.
+%
+%    This work is dedicated to \cfr, without whom it would have never seen the
+%    light, and to whom I~am offering it ``as an Epiphany present''---or rather,
+%    as one would say in Italian, ``\emph{come regalo per la Befana}'', where
+%    the last word bears not-so-subtle connections with the world of
+%    witches\ldots
+%
+%    \subsection{Disclaimer}
+%
+%    Although a \LaTeX\ package is a piece of software that executes in a
+%    rather protected environment and should therefore be relatively
+%    incapable of doing serious damages, no warranty is given, as usual with
+%    computer software, that this code will work properly, or even that it
+%    will work at all.  To be on the safe side, be aware that using this
+%    code can even result in loss of data and/or damages to your disks and
+%    your storage media.  If you use this code, you do so exclusively at
+%    your own risk!
+%
+%    See Subsection~\ref{sS:License} and the \LaTeX\ Project Public
+%    Licence for more information.
+%
+%    \subsection{About this document}
+%
+%    This document, like many documentation files distributed for \LaTeX, is
+%    divided into two parts.
+%
+%    The first part, \emph{User's Manual}, contains all the documentation you
+%    need to be able to \emph{use} the \packlass{\halloweenmath} package.  Every
+%    user of this package will probably want to read this part.
+%
+%    The second part, \emph{Implementation}, can be omitted if you
+%    want (explanations on how to omit it are given at the beginning
+%    of the part itself), and contains information that concerns only
+%    ``hackers'' who want to learn how the package that this document
+%    presents is \emph{implemented}.  Actually, this part contains the
+%    complete listing of the \LaTeX\ code that implements the macros,
+%    in the usual \DS\ format; if you are not a \LaTeX\ hacker, this
+%    part will probably have little meaning to you.
+%
+%    As I~said above, this package is an Epiphany gift for \TeXSXuser{cfr}, and,
+%    for this reason, I~want to submit it to CTAN\@ on January~6, 2017.
+%    Regrettably, I~couldn't write most of the comments in the
+%    \emph{Implemenation} part in time for the submission, which, on the other
+%    hand, I~don't want to defer to a later date for any reason whatsoever.
+%    Some sparse comments, nonetheless, are sprinkled throughout the code at
+%    certain key places, and I~hope they will suffice to understand what's going
+%    on.  I~apologize for submitting this work in an incomplete form;
+%    unfortunately, at present I~cannot even foresee when I'll be able to finish
+%    it.
+%
+%
+%
+% \setcounter{secnumdepth}{3}
+%
+%
+%
+% \clearpage
+% \part{User's Manual}
+%
+% \section{About this part}
+%
+%    This part tells you how to use the \packlass{\halloweenmath} package.  It
+%    also contains detailed instructions on how to install it and how to
+%    generate this same documentation, but normally you need not bother reading
+%    this information, either because your \TeX\ distribution already includes
+%    both the package code and its documentation, or because package
+%    installation is implicitly dealt with by the automatic update mechanism
+%    provided by the distribution itself.
+%
+% \section{How to use the \packlass{\halloweenmath} package}
+% \label{S:Usage}
+%
+%    This section explains everything you need to know in order to be able to
+%    use the \packlass{\halloweenmath} package.  However, to keep this document
+%    independent of the package itself, the output produced by the various
+%    commands is not shown here: for this, you are referred to \cite{bib:manual}
+%    and to~\cite{bib:sample}.
+%
+%    \subsection{Package loading}
+%
+%    The usual "\usepackage" declaration is used, as in
+%    \begin{verbatim}\usepackage{halloweenmath}\end{verbatim} It should be
+%    noted, however, that the \packlass{\halloweenmath} package requires the
+%    \packlass{\amsmath} package, and loads it (without specifying any option)
+%    if it is not already loaded.  If you want to pass options to
+%    \packlass{\amsmath}, load it before \packlass{\halloweenmath}.
+%
+%    The \packlass{\halloweenmath} package defines no options by itself;
+%    nevertheless, it does honor the [\opt{no}]\opt{sumlimits} options from the
+%    \packlass{\amsmath} package (see below).
+%
+%    \subsection{Scary symbols}
+%
+%    This package defines some commands \emph{for use in mathematical mode},
+%    which provide a handful of symbols, all of which honor the \texttt{bold}
+%    math version, when in force.  They can be loosely grouped as follows.
+%
+%    \subsubsection{Pumpkins}
+%
+%    \DescribeMacro{\pumpkin}
+%    \DescribeMacro{\bigpumpkin}
+%    \DescribeMacro{\greatpumpkin}
+%    It is even too obvious to begin with pumpinks.  In this regard, the package
+%    provides two interrelated commands:
+%    \begin{itemize}
+%    \item
+%    "\pumpkin" yields a binary operator symbol in the shape of a (little) 
+%    pumpkin;
+%    \item
+%    "\bigpumpkin" is the ``large'' operator that is to "\pumpkin" as
+%    "\bigoplus" is to "\oplus"; it typesets a somewhat bigger pumpkin in
+%    in-line formulas, which becomes significantly larger in displayed formulas.
+%    \end{itemize}
+%    The [\opt{no}]\opt{sumlimits} options from the \packlass{\amsmath} package
+%    also affect the "\bigpumpkin" command.  As a homage to Linus van Pelt,
+%    "\greatpumpkin" is available as a perfect synonym for "\bigpumpkin".
+%
+%    \subsubsection{Witches, brooms, and black cats}
+%
+%    All this arose from a witch.
+%
+%    \DescribeMacro{\mathwitch} \DescribeMacro{\reversemathwich}
+%    The "\mathwitch" command yields a ``large'' operator symbol, similar to
+%    "\sum", representing a witch astride of a broom (in my answers
+%    to~\cite{bib:cfr}, I~claimed that this symbol denotes the operation of
+%    applying black magic to the ensuing subformula, a fundamental operation in
+%    so many mathematical proofs\ldots).  There is also a "\reversemathwich"
+%    command, which produces an operator that looks like a mirror image of the
+%    above, for denoting the inverse operation of undoing the black magic.  Both
+%    commands honor the [\opt{no}]\opt{sumlimits} options from the
+%    \packlass{\amsmath} package.
+%
+%    \DescribeMacro{\xrightwitchonbroom}
+%    \DescribeMacro{\xleftwitchonbroom}
+%    Witches infest the field of extensible ``arrow-like'' symbols too: the
+%    commands "\xrightwitchonbroom" and "\xleftwitchonbroom" are syntactically
+%    identical to, \emph{e.g.}, "\xrightarrow", but produce an extensible broom
+%    with a witch sitting on it.  That is to say, the syntax for
+%    "\xrightwitchonbroom" is as follows
+%    \begin{flushleft}
+%      \cmd{\xrightwitchonbroom}\oarg{under text}\marg{over text}
+%    \end{flushleft}
+%    and "\xleftwitchonbroom" is similar.
+%
+%    \DescribeMacro{\overrightwitchonbroom}
+%    \DescribeMacro{\overleftwitchonbroom}
+%    \DescribeMacro{\underrightwitchonbroom}
+%    \DescribeMacro{\underleftwitchonbroom}
+%    Finally, the four commands
+%    \begin{flushleft}
+%      "\overrightwitchonbroom "\marg{subformula} \\
+%      "\overleftwitchonbroom  "\marg{subformula} \\
+%      "\underrightwitchonbroom"\marg{subformula} \\
+%      "\underleftwitchonbroom "\marg{subformula}
+%    \end{flushleft}
+%    are similar to, \emph{e.g.}, "\overrightarrow", and typeset a broom, with a
+%    witch sitting on it, over or under the subformula specified in their
+%    argument.\footnote{It should be noted that, in my answers
+%    to~\cite{bib:cfr}, only the command that now corresponds to
+%    \cmd{\overrightwitchonbroom} was provided, but under the different name
+%    \cmd{\overrightbroom}.}
+%
+%    \paragraph*{Important note:}
+%    All the commands described in this subsection have a \mbox{$*$-form} that
+%    adds a black cat on the broomstick.  The syntax should be easy to remember,
+%    since the additional asterisk can be thought of as reminiscent of the cat.
+%
+%    \subsubsection{Ghosts}
+%
+%    Of course, on Hallowen, ghosts cannot be missing either.
+%
+%    \DescribeMacro{\mathghost}
+%    \DescribeMacro{\mathrightghost}
+%    \DescribeMacro{\mathleftghost}
+%    There are three similar commands (without arguments) that produce ordinary
+%    symbols, that is, symbols that are treated like letters: the "\mathghost"
+%    command yield a symbol resembling a ghost standing upfront; the
+%    "\mathrightghost" (resp., "\mathleftghost") command gives a symbol that
+%    looks like a ghost moving toward the right (resp., the left).
+%
+%    \DescribeMacro{\xrightswishingghost}
+%    \DescribeMacro{\xleftswishingghost}
+%    Once again, ghosts too haunt the region of extensible ``arrow-like''
+%    symbols:
+%    \begin{flushleft}
+%      "\xrightswishingghost"\oarg{under text}\marg{over text} \\
+%      "\xleftswishingghost "\oarg{under text}\marg{over text}
+%    \end{flushleft}
+%    are analogous to, \emph{e.g.}, "\xrightarrow", but, in place of the arrow,
+%    draw a ghost swishing, respectively, toward the right and toward the left.
+%
+%    \DescribeMacro{\overrightswishingghost}
+%    \DescribeMacro{\overleftswishingghost}
+%    \DescribeMacro{\underrightswishingghost}
+%    \DescribeMacro{\underleftswishingghost}
+%    It is now easy to guess what the following four commands do:
+%    \begin{flushleft}
+%      "\overrightswishingghost "\marg{subformula} \\
+%      "\overleftswishingghost  "\marg{subformula} \\
+%      "\underrightswishingghost"\marg{subformula} \\
+%      "\underleftswishingghost "\marg{subformula}
+%    \end{flushleft}
+%
+%    \subsubsection{Other symbols}
+%
+%    The \packlass{\halloweenmath} package implements one more symbol that could
+%    loosely be connected with the world of witches.
+%
+%    \DescribeMacro{\mathcloud} \DescribeMacro{\reversemathcloud}
+%    Mathemagicians often deal with unscrutable formulas.  To represent them,
+%    the "\mathcloud" command (without arguments) is available, which produces a
+%    symbol, with the form of a cloud, that behaves to a certain extent like a
+%    fraction, in that it is typeset in a significantly larger size in displayed
+%    formulas than in in-line ones.  The companion command "\reversemathcloud"
+%    yields a mirror image of the same symbol.
+%
+%    \subsection{Script-style version of standard over\protect\slash under
+%      arrows}
+%
+%    In order to implement our over\slash under ``arrow-like'' symbols, we had
+%    to develop an extension of some internal macros of the \packlass{\amsmath}
+%    package.  These extensions can be applied to produce variants of the
+%    standard over\slash under arrows too.
+%
+%    \DescribeMacro{\overscriptrightarrow}
+%    \DescribeMacro{\overscriptleftarrow}
+%    \DescribeMacro{\overscriptleftrightarrow}
+%    \DescribeMacro{\underscriptrightarrow}
+%    \DescribeMacro{\underscriptleftarrow}
+%    \DescribeMacro{\underscriptleftrightarrow}
+%    The following six commands are analogous to their standard counterparts
+%    whose names do not contain the "script" substring, but the arrows they put
+%    above or below the given subformulas are typeset in their relative script
+%    style, instead of in the same style as the subformulas themselves (as the
+%    standard commands do):
+%    \begin{flushleft}
+%      "\overscriptrightarrow     "\marg{subformula} \\
+%      "\overscriptleftarrow      "\marg{subformula} \\
+%      "\overscriptleftrightarrow "\marg{subformula} \\
+%      "\underscriptrightarrow    "\marg{subformula} \\
+%      "\underscriptleftarrow     "\marg{subformula} \\
+%      "\underscriptleftrightarrow"\marg{subformula}
+%    \end{flushleft}
+%
+% \section{Installing the \packlass{\halloweenmath} package and generating this manual}
+%
+%    As usual for \LaTeX\ distributions, the \packlass{\halloweenmath}
+%    package is distributed in the form of a \filedir{.dtx} file,
+%    namely \filedir{\halloweenmath.dtx}, and an accompanying
+%    \filedir{.ins} file, namely \filedir{\halloweenmath.ins}.
+%
+%    \subsection{Installation}
+%
+%    To extract the code, run \LaTeX\ (or plain \TeX) once on the
+%    file \filedir{\halloweenmath.ins}.  This will generate the following
+%    \LaTeX\ input file:
+%    \begin{quote}
+%      \ttfamily
+%      \halloweenmath.sty
+%    \end{quote}
+%    To finish the installation, move it to a \LaTeX\ input directory.  The
+%    above listing of the files you need to move is also displayed on the
+%    terminal at the end of the run of the file \filedir{\halloweenmath.ins}.
+%    The documentation of your \TeX\ installation should tell you how to find
+%    the \LaTeX\ input directory/ies, and probably also how to create new
+%    \LaTeX\ input directories reserved to contain your private classes and
+%    packages.
+%
+%    The \emph{proposed} TDS-compliant directory where the above file should be
+%    put is
+%    \begin{quote}
+%      \texttt{\$TEXMF/tex/latex/halloweenmath/}
+%    \end{quote}
+%
+%    Please note that before using the \packlass{\halloweenmath} package
+%    you must read its license (see Subsection~\ref{sS:License}) to
+%    see whether its terms are acceptable for you, especially for what
+%    concerns the lack of any warranty; if they are not, don't use
+%    this program.
+%
+%    \subsection{Documentation}
+%
+%    To produce this documentation, run \LaTeX\ three times (for the
+%    table of contents to be correct) on the file
+%    \filedir{\halloweenmath.dtx}.  This won't produce the index and the
+%    change history, however: for those, you have to run
+%    \emph{MakeIndex} on the files \filedir{\halloweenmath.idx} and
+%    \filedir{\halloweenmath.glo}, produced during the last of the
+%    aforesaid three \LaTeX\ runs, with the styles \filedir{gind.ist}
+%    and \filedir{gglo.ist}, respectively (these styles are part of
+%    the standard \LaTeX\ distribution); then pass
+%    \filedir{\halloweenmath.dtx} through \LaTeX\ twice more.
+%
+%    The documentation produced by default includes the
+%    \emph{Implementation} part too; see the beginning of this part
+%    for instructions on how to omit it.
+%
+%    \subsection{License}
+%    \label{sS:License}
+%
+%    The \packlass{\halloweenmath} package is \emph{not} in the public
+%    domain: its author, Gustavo \textsc{Mezzetti}, owns the
+%    copyright, and in general retains all the rights therein; but as
+%    a special exception, the author grants you the permissions
+%    indicated below.
+%
+%    \subsubsection{Distribution and/or modification}
+%
+%    The \packlass{\halloweenmath} package may be distributed and/or
+%    modified under the conditions of the \LaTeX\ Project Public
+%    License, either version~1.3 of this license or (at your option)
+%    any later version.  The latest version of this license is in
+%    \begin{quote}
+%      \ttfamily
+%      http://www.latex-project.org/lppl.txt
+%    \end{quote}
+%    and version~1.3 or later is part of all distributions of \LaTeX\
+%    version 2005/12/01 or later.
+%
+%    The \packlass{\halloweenmath} package has the LPPL maintenance status
+%    ``author-maintained''.
+%
+%    The file \filedir{manifest.txt} included along with this file
+%    specifies what the \packlass{\halloweenmath} package consists of; more
+%    precisely, it explains how the locutions ``Work'' and ``Compiled
+%    Work'', used in the \LaTeX\ Project Public License, are to be
+%    interpreted in the case of this work.
+%
+%    \subsubsection{Use}
+%
+%    The use of the \packlass{\halloweenmath} package is unrestricted,
+%    provided that you accept the terms and conditions of the \LaTeX\
+%    Project Public License and of the following subsection for what
+%    concerns the absence of any warranty.
+%
+%    \subsubsection{No warranty}
+%
+%    There is absolutely no warranty for the \packlass{\halloweenmath}
+%    package.  The Copyright Holder provides the \packlass{\halloweenmath}
+%    package ``as is'', without warranty of any kind, either expressed
+%    or implied, including, but not limited to, the implied warranties
+%    of merchantability and fitness for a particular purpose.  The
+%    entire risk as to the quality and performance of the
+%    \packlass{\halloweenmath} package is with you.  Should the
+%    \packlass{\halloweenmath} package prove defective, you assume the cost
+%    of all necessary servicing, repair, or correction.
+%
+%    In no event will The Copyright Holder, or any other party who may
+%    distribute and/or modify the \packlass{\halloweenmath} package as
+%    permitted by the \LaTeX\ Project Public License, be liable to you
+%    for damages, including any general, special, incidental or
+%    consequential damages arising out of any use of the
+%    \packlass{\halloweenmath} package or out of inability to use it
+%    (including, but not limited to, loss of data, data being rendered
+%    inaccurate, or losses sustained by anyone as a result of any
+%    failure of the \packlass{\halloweenmath} package to operate with any
+%    other programs), even if The Copyright Holder or said other party
+%    has been advised of the possibility of such damages.
+%
+% \StopEventually{
+%    \setcounter{secnumdepth}{0}
+%    \providecommand*\bysame{\leavevmode\hbox to3em{\hrulefill}\thinspace}
+%
+%    \clearpage
+%    \pdfbookmark[0]{Back Matter}{BackMatter}
+%    \begin{thebibliography}{9}
+%    \addcontentsline{toc}{section}{\refname}
+%
+%    \bibitem{bib:cfr}
+%      \emph{Seasonal Challenge (Contributions from \TeX ing Dead 
+%        Welcome)},\\
+%      \url{http://tex.stackexchange.com/q/336768/69818}
+%
+%    \bibitem{bib:manual}
+%      \emph{A short manual for the \packlass{\halloweenmath} package},
+%      in preparatiom.
+%
+%    \bibitem{bib:sample}
+%      \emph{A sample article that uses the \packlass{\halloweenmath} package},
+%      in preparation.
+%
+%    \end{thebibliography}
+% }
+%
+%
+%
+% \clearpage
+% \part{Implementation}
+%
+% \section{About this part}
+%
+%    This part is of interest only to \LaTeX\ hackers; to avoid
+%    having this part printed, look in the file \filedir{\filename}
+%    for a line that looks \emph{exactly} like this
+%    \begin{verbatim}%% \OnlyDescription % uncomment to discard Implementation part\end{verbatim}
+%    and remove the two leading percent signs ("%%").
+%
+% \section{A driver for this document}
+%
+%    This part of the file is \emph{not} included in any generated file:
+%    it is simply the driver.
+%    \begin{macrocode}
+%<*driver>
+%    \end{macrocode}
+%
+%    To begin with, we load the \packlass{ltxdoc} class
+%    and the packages we require.
+%    \begin{macrocode}
+\documentclass{ltxdoc}
+\usepackage{color,pict2e,hologo}
+\usepackage{hypdoc}
+%    \end{macrocode}
+%    We now set a few typesetting options.
+%    First of all, we want a history listing and a full index, the latter
+%    organized by line numbers.
+%    \begin{macrocode}
+\RecordChanges
+\EnableCrossrefs
+\CodelineIndex
+%    \end{macrocode}
+%    If you don't want to include the second part of this document,
+%    \emph{Implementation}, uncomment the line containing the command
+%    "\OnlyDescription".
+%    \begin{macrocode}
+%% \OnlyDescription % uncomment to discard Implementation part
+%    \end{macrocode}
+%    Finally, setting "\hfuzz" and "\vfuzz" to 0~points is only one
+%    of the many neurotic symptoms of the author!
+%    \begin{macrocode}
+\hfuzz = 0pt
+\vfuzz = 0pt
+%    \end{macrocode}
+%    Now input this same file, using \DS\ conventions.
+%    \begin{macrocode}
+\begin{document}
+  \DocInput{halloweenmath.dtx}
+%    \end{macrocode}
+%    Then print the change list and the index.  We put these commands in
+%    the driver, rather than in the comments of this file, because
+%    producing the change list and the index is somewhat cumbersome, and some
+%    users could prefer to omit them: such users should simply use a
+%    different driver.
+%    \begin{macrocode}
+  % \clearpage % attach Change history below References
+  \PrintChanges
+  \clearpage \PrintIndex
+%    \end{macrocode}
+%    When this file is read directly by \LaTeX\ without the intervention
+%    of \DS, the following line will make \TeX\ stop
+%    reading.
+%    \begin{macrocode}
+\end{document}
+%    \end{macrocode}
+%    End of driver module.
+%    \begin{macrocode}
+%</driver>
+%    \end{macrocode}
+%
+% \section{The code for the \packlass{\halloweenmath} package}
+%
+%    This part of the file goes into \filedir{\halloweenmath.sty}.
+%    \begin{macrocode}
+%<*halloweenmath>
+%    \end{macrocode}
+%
+%    \subsection{Identification}
+%
+%    No particular reason for asking for a particular release of \LaTeXe; but at
+%    least, let us specify a date on which the \packlass{\picttwoe} package was
+%    likely to exist.
+%    \begin{macrocode}
+\NeedsTeXFormat{LaTeX2e}[2004/06/01] % LaTeX2e is required!
+%    \end{macrocode}
+%    The usual identification:
+%    \begin{macrocode}
+\ProvidesPackage{halloweenmath}
+                [2017/01/06 v0.01 (development)]
+%    \end{macrocode}
+%
+%    \subsection{Initial code}
+%
+%    This segment is empty in the \packlass{\halloweenmath} package.
+%
+%    \subsection{Declaration of options}
+%
+%    This segment is empty in the \packlass{\halloweenmath} package.
+%
+%    \subsection{Option processing}
+%
+%    This segment is empty in the \packlass{\halloweenmath} package.
+%
+%    \subsection{Package loading}
+%
+%    Besides the \packlass{\picttwoe} package, that we need to draw the 
+%    pictures, we also require the \packlass{\amsmath} package.
+%    \begin{macrocode}
+\RequirePackage{amsmath,pict2e}
+%    \end{macrocode}
+%
+%    \subsection{Main code}
+%
+%    Let's begin with an important remark.  It would be pretty easy to fulfill 
+%    the purpose of this package using \TikZ; this has been deliberately 
+%    avoided.  This package has been written for fun, and part of this fun lay 
+%    in the constraint of using only the means provided by the \env{picture} 
+%    environment, albeit with the \packlass{\picttwoe} extensions.  Please 
+%    accept this fact without arguing about it.
+%
+%    The names of all the macros defined in this package start with the prefix 
+%    "\@HwM@" (``namespace'' prefix).
+%
+%    \subsubsection{Preliminary macros}
+%
+%    We begin with defining some macros that provide basic functionality.
+%
+%    \begin{macro}{\@HwM@tempa}
+%    Temporary scratch macro reserved for this package.  Here we just check 
+%    that the name can be used, while, at the same time, reserving it.
+%    \begin{macrocode}
+\@ifdefinable\@HwM@tempa{}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@thickness@units@for}
+%    The unit of measure we are going to use for line thicknesses; since it is
+%    defined in term of the ``default-rule-thickness'' "\fontdimen", it will
+%    automatically scale with the font size.  The suffix "for" at the end of the
+%    names reminds that a font selector like "\textfont" must follow and will be
+%    absorbed as argument~\#1.
+%    \begin{macrocode}
+\newcommand*\@HwM@thickness@units@for[1]{\fontdimen 8 #1\thr@@}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@right@or@left}
+%    Used to pass information about the orientation of left\slash right
+%    symmetric figures.  Here we just check that the name can be used, at the
+%    same time reserving it.
+%    \begin{macrocode}
+\@ifdefinable\@HwM@right@or@left{}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@set@right@dir}
+%    Causes that the following left\slash right symmetric figure to face to the
+%    right.
+%    \begin{macrocode}
+\newcommand*\@HwM@set@right@dir{%
+  \let \@HwM@right@or@left \@firstoftwo
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@set@left@dir}
+%    Causes that the following left\slash right symmetric figure to face to the
+%    left.
+%    \begin{macrocode}
+\newcommand*\@HwM@set@left@dir{%
+  \let \@HwM@right@or@left \@secondoftwo
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{environment}{@HwM@math@picture}
+%    Customized \env{picture} environment for our ``math pictures'', makes some
+%    initializations that are always needed (local to its group).  Arguments:
+%    \begin{paramlist}
+%      \param{1}
+%        bounding box height, in coordinate units;\\
+%      \param{2}
+%        $y$-coordinate of lower left corner of bounding box;\\
+%      \param{3}
+%        additional code to be executed during initialization;\\
+%      \param{4}
+%        font selector (\emph{e.g.}, "\textfont");\\
+%      \param{5}
+%        bounding box width, in coordinate units;\\
+%      \param{6}
+%        $x$-coordinate of lower left corner of bounding box.
+%    \end{paramlist}
+%    \begin{macrocode}
+\newenvironment*{@HwM@math@picture}[6]{%
+  \setlength\unitlength{\fontdimen 22 #4\tw@}%
+  #3%
+  \@HwM@right@or@left{%
+    \def\+{+}%
+    \def\-{-}%
+  }{%
+    \def\+{-}%
+    \def\-{+}%
+  }%
+  \picture(#5,#1)(#6,#2)%
+}{\endpicture}
+%    \end{macrocode}
+%    \end{environment}
+%
+%    \begin{macro}{\@HwM@short@circuited@vphant}
+%    ``Short-circuited'' version of "\vphantom".
+%    \begin{macrocode}
+\newcommand*\@HwM@short@circuited@vphant{\v@true\h@false\mathph@nt}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@oplus@strut}
+%    Vertical phantom the size of "\oplus".  Arguments:
+%    \begin{paramlist}
+%      \param{1}
+%        style selector (\emph{e.g.}, "\displaystyle").
+%    \end{paramlist}
+%    \begin{macrocode}
+\newcommand*\@HwM@oplus@strut[1]{%
+  \@HwM@short@circuited@vphant #1\bigoplus@
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@d@pict@strut}
+%    Inserts a ``depth-only half-strut'' (the~"d" in the name is for ``depth''),
+%    \#1~is its size in picture units.
+%    \begin{macrocode}
+\newcommand*\@HwM@d@pict@strut[1]{%
+  \vrule \@width\z@ \@height\z@ \@depth #1\unitlength
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@large@picture}
+%    \begin{macro}{\end@HwM@large@picture}
+%    This is actually a definition of an environment.  The environment beign
+%    defined, namely \env{@HwM@large@picture}, is simply syntactic sugar for a
+%    typical invocation of the \env{@HwM@math@picture} environment, for a
+%    picture of ``large'' size (\( \mbox{height}=5 \), \( \mbox{depth}=3 \),
+%    with the baseline running at \( y=-1 \)), suitable for the display-style
+%    version of a large operator.  Supplies arguments \#1--\#4 of
+%    \env{@HwM@math@picture}, with \#4 being "\textfont"; the caller must supply
+%    the remaining ones.
+%    \begin{macrocode}
+\newcommand*\@HwM@large@picture{%
+  \@HwM@math@picture{5}{-1}{\@HwM@d@pict@strut\thr@@}\textfont
+}
+\let\end@HwM@large@picture = \end@HwM@math@picture
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@small@picture}
+%    \begin{macro}{\end@HwM@small@picture}
+%    This is actually a definition of an environment.  The environment beign
+%    defined, namely \env{@HwM@small@picture}, is simply syntactic sugar for a
+%    typical invocation of the \env{@HwM@math@picture} environment, for a
+%    picture of ``small'' size (\( \mbox{height}=3 \), \( \mbox{depth}=1 \),
+%    with the baseline running at \( y=-1 \)), suitable for the
+%    non-display-style version of a large operator.  Supplies arguments \#1--\#3
+%    of \env{@HwM@math@picture}; the caller must supply the remaining ones,
+%    \emph{including} argument~\#4.
+%    \begin{macrocode}
+\newcommand*\@HwM@small@picture{%
+  \@HwM@math@picture{3}{-1}{\@HwM@d@pict@strut\@ne}%
+}
+\let\end@HwM@small@picture = \end@HwM@math@picture
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@oplus@picture}
+%    \begin{macro}{\end@HwM@oplus@picture}
+%    This is actually a definition of an environment.  The environment beign
+%    defined, namely \env{@HwM@oplus@picture}, is simply syntactic sugar for a
+%    typical invocation of the \env{@HwM@math@picture} environment, for a
+%    picture having the vertical size of an "\oplus", with baseline running at
+%    \( y=-1 \).  Supplies arguments \#1--\#3 of \env{@HwM@math@picture}; the
+%    caller must supply the others, \emph{including} argument~\#4.
+%    \begin{macrocode}
+\newcommand*\@HwM@oplus@picture[1]{%
+  \@HwM@math@picture{0}{-1}{\@HwM@oplus@strut #1}%
+}
+\let\end@HwM@oplus@picture = \end@HwM@math@picture
+%    \end{macrocode}
+%    \end{macro}
+%    \end{macro}
+%
+%    \begin{macro}{\if@HwM@cat@}
+%    Switch that tells whether a witch that is about to be drawn should be 
+%    accompanied by her cat or not.
+%    \begin{macrocode}
+\@ifdefinable\if@HwM@cat@{\newif\if@HwM@cat@}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    The following two macros should probably be unified (but is this
+%    feasible?\@), since the first one isn't used elsewhere in the code.
+%
+%    \begin{macro}{\@HwM@if@bold@math}
+%    \LaTeX-style conditional: if the math version is currently \texttt{bold},
+%    executes the code in the first argument, otherwise the code in the second
+%    argument.
+%    \begin{macrocode}
+\newcommand*\@HwM@if@bold@math{%
+  \def\@tempa{bold}%
+  \ifx\math@version\@tempa
+    \expandafter\@firstoftwo
+  \else
+    \expandafter\@secondoftwo
+  \fi
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@choose@thicknesses}
+%    Shuffles arguments according to the current math version.
+%    \begin{macrocode}
+\newcommand*\@HwM@choose@thicknesses[3]{%
+  \@HwM@if@bold@math{#1#3}{#1#2}
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@magic@star}
+%    Draws a star; argument~\#1 is a scale factor.
+%    \begin{macrocode}
+\newcommand*{\@HwM@magic@star}[1]{%
+  \begingroup
+    \setlength\unitlength{#1\unitlength}%
+    \picture(0,0)%
+      \polygon*(0,1)(-.225,.309)(-.951,.309)(-.363,-.118)(-.588,-.809)%
+              (0,-.382)(.588,-.809)(.363,-.118)(.951,.309)(.225,.309)%
+    \endpicture
+  \endgroup
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \paragraph*{General remark:}
+%    In all of the following drawings, the thickness of most of the lines
+%    depends on the current math style.  On the other hand, some pictures are
+%    made up of smaller reusable pieces that are shared among more than one
+%    drawing.  As a matter of mental order, I~prefer to confine the lookup for
+%    the current style to a single place for each picture, and pass the
+%    appropriate thicknesses down to the macros that draw the single pieces as
+%    parameters.  Nonetheless, the interface toward the rest of the code
+%    requires macros that can draw a picture without requiring the caller to
+%    specify thickness arguments.  This means that some drawing macros must
+%    exist in two variants:
+%    \begin{itemize}
+%      \item
+%        a ``private'' variant that requires the caller to specify thickness 
+%        parameters;
+%      \item
+%        a ``public'' variant that doesn't require such parameters, but uses,
+%        instead, the "\@HwM@choose@thicknesses" macro to find out the
+%        appropriate thickness values by itself.
+%    \end{itemize}
+%    To make it clear when two macros are actually two such variants of the same
+%    conceptual function, we shall consistently adhere to the following naming
+%    convention:
+%    \begin{itemize}
+%      \item
+%        the name of the``private'' private variant will be made up of words
+%        separated by "@"~characters, and each of those word will \emph{not} be
+%        capitalized (for example, "\@HwM@large@witch");
+%      \item
+%        the name of the ``public'' variant will be composed by exactly the same
+%        words, again separated by "@"~characters, \emph{but} with each word
+%        being also capitalized (for example, "\@HwM@Large@Witch").
+%    \end{itemize}
+%    Note, though, that the ``public'' variant of a macro will typically (but
+%    not always) require the caller to specify a font selector like "\textfont";
+%    we'll see that, from the point of view of the other parts of the code, this
+%    is an acceptable requirement for the interface.
+%
+%    \subsubsection{Drawing the witch (and the cat)}
+%
+%    The following macros are responsible for the bulk of the task of drawing
+%    the witch (with an optional cat).  Figure~\ref{fig:witch} shows a sketch of
+%    this drawing.
+%
+%    \begin{figure}[tp]
+%      \centering
+%      The small variant:\\*[\bigskipamount]
+%      \begin{picture}(6,4)(-3,-2)
+%        \linethickness{.1pt}
+%        \color{guidelines}
+%        \multiput(-3,-2)(1,0){7}{\line(0,1){4}}
+%        \multiput(-3,-2)(0,1){5}{\line(1,0){6}}
+%        \color{black}
+%        \linethickness{3pt}
+%        \roundcap
+%        \Line(-1,-1)(3,1)
+%        \linethickness{1.5pt}
+%        \Line(-1,-1)(-2.5,-1.25)
+%        \Line(-1,-1)(-2.4,-1.5)
+%        \Line(-1,-1)(-2.25,-1.75)
+%        \Line(-1,-1)(-2,-2)
+%        \put(-1.7,-.4){\magicstar{.4}}
+%        \put(-2.7,-.8){\magicstar{.25}}
+%        \Line(0,.9)(-.1,.7)
+%        \polyline(.3,1.6)(.4,1.5)(.75,1.5)(.9,1.2)(.5,1.2)
+%                (.6,1)(.8,.9)(.7,.75)(0,.9)(-.1,1)
+%        \Line(.1,1.4)(.3,1.5)
+%        \polygon*(-.5,1)(-1,0)(-1,-.5)(-.75,-1)(.5,-1)
+%                (0,-1.8)(.2,-1.9)(.3,-1.7)(.4,-2)(1,-2)
+%                (.5,-1.8)(.5,-1.5)(.8,-1.6)(1,-.75)(0,-.5)
+%                (0,-.3)(.7,-.3)(.9,-.2)(1,0)(0,0)
+%                (0,.7)
+%        \polygon*(-1.5,1)(-1.4,1.5)(-1,2)(-.5,2)(0,1.75)
+%                (.5,1.9)(1.25,1.75)(0,1.5)(-.5,1)(-1,.8)
+%                (-1.2,1)(-1,1)(-.5,1.5)(-1,1.75)(-1.3,1.5)
+%        ^^A
+%        ^^A The cat:
+%        \put(1.8,.5){\circle*{.6}}
+%        \put(2.1,.7){\circle*{.5}}
+%        \put(2.25,1){\circle*{.4}}
+%        \polygon*(2.05,1)(2.05,1.25)(2.25,1.1)(2.45,1.25)(2.45,1)
+%        \linethickness{3pt}
+%        \cbezier(1.6,.3)(1,0)(2.1,-.2)(1.5,-.5)
+%      \end{picture}
+%
+%      \bigskip\bigskip\bigskip
+%
+%      The large variant:\\*[\bigskipamount]
+%      \begin{picture}(12,8)(-6,-4)
+%        \linethickness{.1pt}
+%        \color{guidelines}
+%        \multiput(-6,-4)(1,0){13}{\line(0,1){8}}
+%        \multiput(-6,-4)(0,1) {9}{\line(1,0){12}}
+%        \color{black}
+%        \roundcap
+%        \linethickness{4pt}
+%        \Line(-2,-2)(6,2)
+%        \linethickness{2pt}
+%        \Line(-2,-2)(-5,-2.5)
+%        \Line(-2,-2)(-4.85,-2.95)
+%        \Line(-2,-2)(-4.6,-3.3)
+%        \Line(-2,-2)(-4.35,-3.65)
+%        \Line(-2,-2)(-4,-4)
+%        \put(-3,-1.2){\magicstar{.4}}
+%        \put(-4.1,-.8){\magicstar{.8}}
+%        \put(-5.4,-1.8){\magicstar{.6}}
+%        \Line(0,1.8)(-.2,1.4)
+%        \polyline(.6,3.2)(.8,3)(1.5,3)
+%        \put(1.6,3){\oval(.2,.2)[tl]}
+%        \put(1.6,3){\oval(.2,.2)[r]}
+%        \polyline(1.6,2.9)(1.8,2.4)(1.2,2.4)(1,2.5)(1,2.3)
+%                (1.2,2)(1.6,1.8)(1.7,1.8)(1.7,1.6)(1.4,1.5)
+%                (0,1.8)(-.2,2)
+%        \Line(.2,2.8)(.6,3)
+%        \polygon*(-1,2)(-2,0)(-2,-1)(-1.5,-2)(1,-2)
+%                (0,-3.6)(.4,-3.8)(.6,-3.4)(.8,-4)(2,-4)
+%                (1,-3.6)(1,-3)(1.6,-3.2)(2,-1.5)(0,-1)
+%                (0,-.6)(1.4,-.6)(1.8,-.4)(2,0)(0,0)
+%                (0,1.4)
+%        \polygon*(-3,2)(-2.8,3)(-2,4)(-1.5,4.1)(-1,4)(0,3.5)
+%                (1,3.8)(2.5,3.5)(3,3.3)(2,3.4)(0,3)(-1,2)(-2,1.6)
+%                (-2.7,2)(-2,2)(-1,3)(-2,3.5)(-2.6,3)
+%        \linethickness{.4pt}
+%        \Line(1.7,1.6)(2,1.6)
+%        \Line(1.7,1.6)(1.9,1.4)
+%        \Line(1.7,1.6)(1.7,1.3)
+%        ^^A
+%        ^^A The cat:
+%        \put(3.6,1){\circle*{1.2}}
+%        \put(4.2,1.4){\circle*{1}}
+%        \put(4.5,2){\circle*{.8}}
+%        \polygon*(4.1,2)(4.1,2.5)(4.5,2.2)(4.9,2.5)(4.9,2)
+%        \linethickness{4pt}
+%        \cbezier(3.2,.6)(2,0)(4.2,-.4)(3,-1)
+%        \buttcap
+%        \linethickness{.4pt}
+%        \Line(3.8,2.1)(5.2,1.9)
+%        \Line(3.8,2)(5.2,2)
+%        \Line(3.8,1.9)(5.2,2.1)
+%      \end{picture}
+%
+%      \caption{Sketches of the witch}
+%      \label{fig:witch}
+%    \end{figure}
+%
+%    \begin{macro}{\@HwM@large@witch}
+%    This is the macro that draws the ``large'' version of the witch (for
+%    "\displaystyle").  This is the ``private'' variant, with the following
+%    parameters:
+%    \begin{paramlist}
+%      \param{1}
+%        "l"~for a right-facing witch, "r"~for a left-facing one;\\
+%      \param{2}
+%        "r"~for a right-facing witch, "l"~for a left-facing one;\\
+%      \param{3}
+%        main drawing thickness, in units of the default-rule-thickness
+%        "\fontdimen";\\
+%      \param{4}
+%        thickness of the broomstick and of the cat's tail, in the same units;\\
+%      \param{5}
+%        thickness of hair (beard, whiskers), in the same units.
+%    \end{paramlist}
+%    \begin{macrocode}
+\newcommand*\@HwM@large@witch[5]{%
+  \begin{@HwM@large@picture}{12}{-6}%
+    \roundcap
+    \linethickness{#4\@HwM@thickness@units@for \textfont}%
+    \Line(\-2,-2)(\+6,2)%
+    \linethickness{#3\@HwM@thickness@units@for \textfont}%
+    \Line(\-2,-2)(\-5,-2.5)%
+    \Line(\-2,-2)(\-4.85,-2.95)%
+    \Line(\-2,-2)(\-4.6,-3.3)%
+    \Line(\-2,-2)(\-4.35,-3.65)%
+    \Line(\-2,-2)(\-4,-4)%
+    \put(\-3,-1.2){\@HwM@magic@star{.4}}%
+    \put(\-4.1,-.8){\@HwM@magic@star{.8}}%
+    \put(\-5.4,-1.8){\@HwM@magic@star{.6}}%
+    \Line(0,1.8)(\-.2,1.4)%
+    \polyline(\+.6,3.2)(\+.8,3)(\+1.5,3)%
+    \put(\+1.6,3){\oval(.2,.2)[t#1]}%
+    \put(\+1.6,3){\oval(.2,.2)[#2]}%
+    \polyline(\+1.6,2.9)(\+1.8,2.4)(\+1.2,2.4)(\+1,2.5)(\+1,2.3)%
+            (\+1.2,2)(\+1.6,1.8)(\+1.7,1.8)(\+1.7,1.6)(\+1.4,1.5)%
+            (0,1.8)(\-.2,2)%
+    \polygon*(\-1,2)(\-2,0)(\-2,-1)(\-1.5,-2)(\+1,-2)%
+            (0,-3.6)(\+.4,-3.8)(\+.6,-3.4)(\+.8,-4)(\+2,-4)%
+            (\+1,-3.6)(\+1,-3)(\+1.6,-3.2)(\+2,-1.5)(0,-1)%
+            (0,-.6)(\+1.4,-.6)(\+1.8,-.4)(\+2,0)(0,0)%
+            (0,1.4)%
+    \polygon*(\-3,2)(\-2.8,3)(\-2,4)(\-1.5,4.1)(\-1,4)(0,3.5)%
+            (\+1,3.8)(\+2.5,3.5)(\+3,3.3)(\+2,3.4)(0,3)(\-1,2)(\-2,1.6)%
+            (\-2.7,2)(\-2,2)(\-1,3)(\-2,3.5)(\-2.6,3)%
+    \buttcap
+%    \end{macrocode}
+%    The witch's eye:
+%    \begin{macrocode}
+    \Line(\+.2,2.8)(\+.6,3)%
+%    \end{macrocode}
+%    Rest of the code:
+%    \begin{macrocode}
+    \linethickness{#5\p@}%
+    \Line(\+1.7,1.6)(\+2,1.6)%
+    \Line(\+1.7,1.6)(\+1.9,1.4)%
+    \Line(\+1.7,1.6)(\+1.7,1.3)%
+    \if@HwM@cat@
+      \Line(\+3.8,2.1)(\+5.2,1.9)%
+      \Line(\+3.8,2)(\+5.2,2)%
+      \Line(\+3.8,1.9)(\+5.2,2.1)%
+      \roundcap
+      \linethickness{#4\@HwM@thickness@units@for \textfont}%
+      \put(\+3.6,1){\circle*{1.2}}%
+      \put(\+4.2,1.4){\circle*{1}}%
+      \put(\+4.5,2){\circle*{.8}}%
+      \polygon*(\+4.1,2)(\+4.1,2.5)(\+4.5,2.2)(\+4.9,2.5)(\+4.9,2)%
+      \cbezier(\+3.2,.6)(\+2,0)(\+4.2,-.4)(\+3,-1)%
+    \fi
+  \end{@HwM@large@picture}%
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@Large@Witch}
+%    The ``public'' variant of the above, with the following parameters:
+%    \begin{paramlist}
+%      \param{1}
+%        "l"~for a right-facing witch, "r"~for a left-facing one;\\
+%      \param{2}
+%        "r"~for a right-facing witch, "l"~for a left-facing one.
+%    \end{paramlist}
+%    \begin{macrocode}
+\newcommand*\@HwM@Large@Witch[2]{%
+  \@HwM@choose@thicknesses{\@HwM@large@witch #1#2}%
+        {{.4}{1.8}{.1}}%
+        {{.8}{2.7}{.15}}%
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@common@small@body}
+%    The macros that draw the ``small'' version of the witch (for styles others
+%    than "\displaystyle") are more complex, because some parts of the drawing
+%    are shared also by the extensible brooms ("\xrightwicthonbroom",
+%    "\overrightwitchonbroom", and the like).  The following macro draws the
+%    parts that are common to all such constructions.  This is the ``private''
+%    variant, with the following parameters:
+%    \begin{paramlist}
+%      \param{1}
+%        font selector (\emph{e.g.}, "\textfont");\\
+%      \param{2}
+%        line thickness for the witch's face, in relative units.
+%    \end{paramlist}
+%    \begin{macrocode}
+\newcommand*\@HwM@common@small@body[2]{%
+  \linethickness{#2\@HwM@thickness@units@for #1}%
+  \buttcap
+%    \end{macrocode}
+%    The witch's eye:
+%    \begin{macrocode}
+  \Line(\+.1,1.4)(\+.3,1.5)%
+%    \end{macrocode}
+%    Rest of the code:
+%    \begin{macrocode}
+  \roundcap
+  \Line(0,.9)(\-.1,.7)%
+  \polyline(\+.3,1.6)(\+.4,1.5)(\+.75,1.5)(\+.9,1.2)(\+.5,1.2)%
+          (\+.6,1)(\+.8,.9)(\+.7,.75)(0,.9)(\-.1,1)%
+  \polygon*(\-.5,1)(\-1,0)(\-1,-.5)(\-.75,-1)(\+.5,-1)%
+          (0,-1.8)(\+.2,-1.9)(\+.3,-1.7)(\+.4,-2)(\+1,-2)%
+          (\+.5,-1.8)(\+.5,-1.5)(\+.8,-1.6)(\+1,-.75)(0,-.5)%
+          (0,.7)%
+  \polygon*(\-1.5,1)(\-1.4,1.5)(\-1,2)(\-.5,2)(0,1.75)%
+          (\+.5,1.9)(\+1.25,1.75)(0,1.5)(\-.5,1)(\-1,.8)%
+          (\-1.2,1)(\-1,1)(\-.5,1.5)(\-1,1.75)(\-1.3,1.5)%
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@Common@Small@Body}
+%    The ``public'' variant of the above; parameters:
+%    \begin{paramlist}
+%      \param{1}
+%        font selector (\emph{e.g.}, "\textfont").
+%    \end{paramlist}
+%    \begin{macrocode}
+\newcommand*\@HwM@Common@Small@Body[1]{%
+  \@HwM@choose@thicknesses {\@HwM@common@small@body #1}{{.35}}{{.7}}%
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@common@small@cat}
+%    Draw the part of the cat that is shared also by the extensible brooms;
+%    ``private'' variant, parameters are as follows:
+%    \begin{paramlist}
+%      \param{1}
+%        font selector (\emph{e.g.}, "\textfont");\\
+%      \param{2}
+%        line thickness for the cat's tail, in relative units.
+%    \end{paramlist}
+%    \begin{macrocode}
+\newcommand*\@HwM@common@small@cat[2]{%
+  \roundcap
+  \linethickness{#2\@HwM@thickness@units@for #1}%
+  \if@HwM@cat@
+    \put(\+1.8,.5){\circle*{.6}}%
+    \put(\+2.1,.7){\circle*{.5}}%
+    \put(\+2.25,1){\circle*{.4}}%
+    \polygon*(\+2.05,1)(\+2.05,1.25)(\+2.25,1.1)(\+2.45,1.25)(\+2.45,1)%
+    \cbezier(\+1.8,.4)(\+1.2,.1)(\+2,-.1)(\+1.4,-.4)%
+  \fi
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@Common@Small@Cat}
+%    The ``public'' variant of the above; parameters:
+%    \begin{paramlist}
+%      \param{1}
+%        font selector (\emph{e.g.}, "\textfont").
+%    \end{paramlist}
+%    \begin{macrocode}
+\newcommand*\@HwM@Common@Small@Cat[1]{%
+  \@HwM@choose@thicknesses {\@HwM@common@small@cat #1}{{}}{{2}}%
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \begin{macro}{\@HwM@Small@Witch}
+%    This is the macro that draws the complete ``small'' variant of the witch
+%    (for styles other than "\displaystyle").  This one exists only in the
+%    ``public'' variant, with the following arguments:
+%    \begin{paramlist}
+%      \param{1}
+%        style selector (\emph{e.g.}, "\displaystyle");\\
+%      \param{2}
+%        font selector (\emph{e.g.}, "\textfont").
+%    \end{paramlist}
+%    The first parameter is imposed by the interface toward other parts of the
+%    code, because other macros that share the same interface might need it, but
+%    isn't actually used in this case.
+%    \begin{macrocode}
+\newcommand*\@HwM@Small@Witch[2]{%
+  \begin{@HwM@small@picture}#2{6}{-3}%
+    \@HwM@Common@Small@Cat #2%
+    \Line(\-1,-1)(\+3,1)%
+    \@HwM@Common@Small@Body #2%
+    \Line(\-1,-1)(\-2.5,-1.25)%
+    \Line(\-1,-1)(\-2.4,-1.5)%
+    \Line(\-1,-1)(\-2.25,-1.75)%
+    \Line(\-1,-1)(\-2,-2)%
+    \put(\-1.7,-.4){\@HwM@magic@star{.4}}%
+    \put(\-2.7,-.8){\@HwM@magic@star{.25}}%
+    \polygon*(0,-.3)(\+.7,-.3)(\+.9,-.2)(\+1,0)(0,0)%
+  \end{@HwM@small@picture}%
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \textbf{Uncommented code} starts here.
+%    \begin{macrocode}
+%
+% Drawing the small witch w/o the broom:
+\newcommand*\@HwM@Small@Witch@Wo@Broom[1]{%
+  \begin{@HwM@math@picture}{4}{-2}{}#1{0}{\+1}%
+    \@HwM@Common@Small@Body #1%
+    \polygon*(\-.1,.4)(\+1,-.9)(\+1,-1.2)(\+.8,-1.2)(\-.1,0)%
+  \end{@HwM@math@picture}%
+}
+%
+% Drawing the cat on a horizontal broomstick:
+\newcommand*\@HwM@Small@Cat@On@Hori@Broom[1]{%
+  \begin{@HwM@math@picture}{0}{-.6}{}#1{0}{\+2.5}%
+    \@HwM@Common@Small@Cat #1%
+    \Line(\+2.2,.8)(\+2.4,.4)%
+  \end{@HwM@math@picture}%
+}
+%
+% Pumpkins.
+\newcommand*\@HwM@large@pumpkin@profile[1]{%
+  \cbezier(#1.15,2.25)(#12.63,3.75)(#13.38,1.5)(#13.38,0)%
+  \cbezier(#1.15,-2.7)(#12.4,-3.6)(#13.38,-1.5)(#13.38,0)%
+  \put(#11.13,1.13){\circle*{.8}}%
+}
+\newcommand*\@HwM@large@pumpkin@mouth[9]{%
+    \polygon*%
+        % lower lip:
+        (-#1)(-#2)(-#3)(-#4)(0,#5)(#4)(#3)(#2)(#1)%
+        % upper lip:
+        (#6)(#7)(#8)(0,#9)(-#8)(-#7)(-#6)%
+}
+\newcommand*\@HwM@large@pumpkin[1]{%
+  \begin{@HwM@oplus@picture}\displaystyle \textfont {7.5}{-3.75}%
+    \roundcap
+    \linethickness{#1\@HwM@thickness@units@for \textfont}%
+    \Line(-.15,2.25)(-.3,3)(.3,3)(.15,2.25)%
+    \Line(-.15,-2.7)(.15,-2.7)%
+    \@HwM@large@pumpkin@profile-%
+    \@HwM@large@pumpkin@profile+%
+    \polygon*(0,.35)(-.35,-.35)(.35,-.35)%
+    \@HwM@large@pumpkin@mouth{2,-.5}{1.3,-1.4}{.8,-1.3}{.5,-1.6}%
+        {-1.5}%
+        {1.2,-1.1}{.7,-1}{.45,-1.1}%
+        {-1}%
+  \end{@HwM@oplus@picture}%
+}
+\newcommand*\@HwM@Large@Pumpkin{%
+  \@HwM@choose@thicknesses \@HwM@large@pumpkin
+        {{1.8}}%
+        {{2.2}}%
+}
+\newcommand*\@HwM@small@pumpkin@profile[1]{%
+  \cbezier(#1.1,1.5)(#11.75,2.5)(#12.25,1)(#12.25,0)%
+  \cbezier(#1.1,-1.8)(#11.6,-2.4)(#12.25,-1)(#12.25,0)%
+  \put(#1.75,.75){\circle*{.5}}%
+}
+\newcommand*\@HwM@small@pumpkin@mouth[7]{%
+    \polygon*%
+        % lower lip:
+        (-#1)(-#2)(-#3)(0,#4)(#3)(#2)(#1)%
+        % upper lip:
+        (#5)(#6)(0,#7)(-#6)(-#5)%
+}
+\newcommand*\@HwM@small@pumpkin[3]{%
+  \begin{@HwM@oplus@picture}#1#2{5}{-2.5}%
+    \roundcap
+    \linethickness{#3\@HwM@thickness@units@for #2}%
+    \Line(-.1,1.5)(-.15,2)(.15,2)(.1,1.5)%
+    \Line(-.1,-1.8)(.1,-1.8)%
+    \@HwM@small@pumpkin@profile-%
+    \@HwM@small@pumpkin@profile+%
+    \polygon*(0,.2)(-.2,-.2)(.2,-.2)%
+    \@HwM@small@pumpkin@mouth{1.3,-.3}{.8,-.8}{.5,-.7}%
+        {-1}%
+        {.7,-.6}{.4,-.5}%
+        {-.7}%
+  \end{@HwM@oplus@picture}%
+}
+\newcommand*\@HwM@Small@Pumpkin[2]{%
+  \@HwM@choose@thicknesses{\@HwM@small@pumpkin #1#2}%
+        {{}}%
+        {{1.5}}%
+}
+\newcommand*\@HwM@oplus@pumpkin@profile[1]{%
+  \cbezier(#1.1,1)(#11.2,1.7)(#11.6,.8)(#11.6,0)%
+  \cbezier(#1.1,-1)(#11,-1.5)(#11.6,-.8)(#11.6,0)%
+  \put(#1.6,.5){\circle*{.4}}%
+}
+\newcommand*\@HwM@oplus@pumpkin[3]{%
+  \begin{@HwM@oplus@picture}#1#2{3.6}{-1.8}%
+    \roundcap
+    \linethickness{#3\@HwM@thickness@units@for #2}%
+    \Line(-.1,1)(-.15,1.4)(.15,1.4)(.1,1)%
+    \Line(-.1,-1)(.1,-1)%
+    \@HwM@oplus@pumpkin@profile-%
+    \@HwM@oplus@pumpkin@profile+%
+    \@HwM@small@pumpkin@mouth{1,-.1}{.7,-.5}{.4,-.4}%
+        {-.7}%
+        {.6,-.3}{.3,-.2}%
+        {-.4}%
+  \end{@HwM@oplus@picture}%
+}
+\newcommand*\@HwM@Oplus@Pumpkin[2]{%
+  \@HwM@choose@thicknesses{\@HwM@oplus@pumpkin #1#2}%
+        {{.6}}%
+        {{1.2}}%
+}
+%
+% Clouds.
+\newcommand*\@HwM@large@cloud[1]{%
+  \begin{@HwM@large@picture}{12}{-6}%
+    \roundcap
+    \linethickness{#1\@HwM@thickness@units@for \textfont}%
+    \cbezier(\-5,0)(\-7,.5)(\-5.5,3.25)(\-4,2.5)%
+    \cbezier(\-3.8,2.1)(\-4.75,3.5)(\-2,4)(\-2,3)%
+    \cbezier(\-2.4,2.5)(\-1.5,4)(\+2,5)(\+2,3)%
+    \cbezier(\+1.8,2.8)(\+2.5,4)(\+4.5,2.5)(\+2.8,1.8)%
+    \cbezier(\+3.2,2)(\+7,2)(\+6,0)(\+5,0)%
+    \cbezier(\+5,0)(\+6,0)(\+6.25,-1)(\+5.3,-1.4)%
+    \cbezier(\+4.6,-1.1)(\+6.8,-1.5)(\+4.3,-4)(\+3.6,-2.1)%
+    \cbezier(\+3.9,-2.6)(\+4,-3)(\+2,-5)(0,-3)%
+    \cbezier(\+.2,-2.4)(\-.2,-4.5)(\-4.5,-4)(\-4,-2)%
+    \cbezier(\-3.4,-2)(\-5.5,-2)(\-6.5,-.5)(\-5,0)%
+  \end{@HwM@large@picture}%
+}
+\newcommand*\@HwM@Large@Cloud{%
+  \@HwM@choose@thicknesses \@HwM@large@cloud
+        {{.8}}%
+        {{1.6}}%
+}
+\newcommand*\@HwM@small@cloud[2]{%
+  \begin{@HwM@small@picture}#1{6}{-3}%
+    \roundcap
+    \linethickness{#2\@HwM@thickness@units@for #1}%
+    \cbezier(\-2.5,0)(\-3.5,.25)(\-3,2)(\-1,1.5)%
+    \cbezier(\-1.2,1.25)(\-.75,2)(\+1,2.5)(\+1,1.5)%
+    \cbezier(\+.9,1.4)(\+1.25,2)(\+2.25,1.25)(\+1.4,.9)%
+    \cbezier(\+1.6,1)(\+3.5,1)(\+3,0)(\+2.5,0)%
+    \cbezier(\+2.5,0)(\+3,0)(\+3.5,-1)(\+2.1,-1.2)%
+    \cbezier(\+2.5,-1.1)(\+2.5,-2)(\+1,-2.5)(0,-1.5)%
+    \cbezier(\+.1,-1.2)(\-.1,-2.25)(\-2.25,-2)(\-2,-1)%
+    \cbezier(\-1.7,-1)(\-2.75,-1)(\-3.25,-.25)(\-2.5,0)%
+  \end{@HwM@small@picture}%
+}
+\newcommand*\@HwM@Small@Cloud[2]{%
+  \@HwM@choose@thicknesses{\@HwM@small@cloud #2}%
+        {{.5}}%
+        {{1.2}}%
+}
+%
+% Ghosts.
+\newcommand*\@HwM@symm@ghost@contour[8]{%
+  \cbezier(-#1,#2)(-#3,#4)(-#3,#5)(-#3,#6)%
+  \Line(-#3,#6)(-#3,#7)%
+  \cbezier(#1,#2)(#3,#4)(#3,#5)(#3,#6)%
+  \Line(#3,#6)(#3,#7)%
+  \cbezier(-#3,#7)(-#3,#8)(#3,#8)(#3,#7)%
+}
+\newcommand*\@HwM@symm@ghost@border[8]{%
+  \cbezier(-#1,#2)(-#3,#4)(-#5,#6)(-#7,#2)%
+  \qbezier(-#7,#2)(0,#8)(#7,#2)%
+  \cbezier(#1,#2)(#3,#4)(#5,#6)(#7,#2)%
+}
+\newcommand*\@HwM@symm@ghost@eyes[3]{%
+  \put(-#1,#2){\circle*{#3}}%
+  \put(#1,#2){\circle*{#3}}%
+}
+\newcommand*\@HwM@symmetric@ghost[3]{%
+  \begin{@HwM@math@picture}{2.6}{-1}%
+            {\@HwM@d@pict@strut{.6}}#1{3.2}{-1.6}%
+    \roundcap
+    \linethickness{#2\@HwM@thickness@units@for #1}%
+    \@HwM@symm@ghost@contour{1.5}{-1.5}{1}{-1}{-.5}{0}{.5}{2}%
+    \linethickness{#3\@HwM@thickness@units@for #1}%
+    \@HwM@symm@ghost@border{1.5}{-1.5}{1.1}{-1.1}{.7}{-1.9}{.3}{-1.2}%
+    \@HwM@symm@ghost@eyes{.4}{.7}{.4}%
+  \end{@HwM@math@picture}%
+}
+\newcommand*\@HwM@Symmetric@Ghost[2]{%
+  \@HwM@choose@thicknesses{\@HwM@symmetric@ghost #2}%
+        {{.9}{.6}}%
+        {{1.8}{1.2}}%
+}
+\newcommand*\@HwM@asymmetric@ghost[3]{%
+  \begin{@HwM@math@picture}{2.6}{-1}%
+            {\@HwM@d@pict@strut{.6}}#1{3.8}%
+            {-\@HwM@right@or@left{1.6}{2.2}}%
+    \roundcap
+    \linethickness{#2\@HwM@thickness@units@for #1}%
+    \cbezier(\-1.75,-1.5)(\-1,-1)(\-.7,-.5)(\-.5,0)%
+    \cbezier(\-.5,0)(\-.3,.5)(0,1.6)(\+1,1.6)%
+    \cbezier(\+1,1.6)(\+1.8,1.6)(\+1.8,.9)(\+1.8,.6)%
+    \cbezier(\+1.8,.6)(\+1.8,-.3)(\+.9,-.7)(\+1.25,-1.5)%
+    \linethickness{#3\@HwM@thickness@units@for #1}%
+    \cbezier(\-1.75,-1.5)(\-1.4,-1.2)(\-1.1,-1.8)(\-.75,-1.5)%
+    \cbezier(\-.75,-1.5)(\-.4,-1.2)(\-.1,-1.8)(\+.25,-1.5)%
+    \cbezier(\+.25,-1.5)(\+.6,-1.2)(\+.9,-1.8)(\+1.25,-1.5)%
+    \put(\+1.2,.7){\circle*{.4}}%
+  \end{@HwM@math@picture}%
+}
+\newcommand*\@HwM@Asymmetric@Ghost[2]{%
+  \@HwM@choose@thicknesses{\@HwM@asymmetric@ghost #2}%
+        {{.9}{.6}}%
+        {{1.8}{1.2}}%
+}
+
+% Extensible arrow-like symbols.
+\newlength\@HwM@arrowfill@skip
+%    \end{macrocode}
+%
+%    \begin{macro}{\@HwM@auto@font@selector}
+%    Suppose you have \meta{something} (\emph{e.g.}, a macro token) that expects
+%    to be followed by a pair \meta{style selector}\meta{font selector}, where
+%    \meta{style selctor} is a single token like "\displaystyle" or
+%    "\scriptscriptstyle", and \meta{font selector} is a single token like
+%    "\textfont" or "\scriptfont"; then
+%    \begin{flushleft}
+%      "\@HwM@auto@font@selector{"\meta{something}"}"\meta{style selector}
+%    \end{flushleft}
+%    is transformed into
+%    \begin{flushleft}
+%      \meta{something}\meta{style selector}\meta{font selector}
+%    \end{flushleft}
+%    where \meta{style selector} is the same style selector as the one that was
+%    originally present, and \meta{font selector} is the correct font selector
+%    associated with it (that is, "\textfont" for "\displaystyle" and
+%    "\textstyle", and so on).  For example,
+%    \begin{flushleft}
+%      "\@HwM@auto@font@selector{"\meta{something}"}\scriptstyle"
+%    \end{flushleft}
+%    is transformed into
+%    \begin{flushleft}
+%      \meta{something}"\scriptstyle\scriptfont"
+%    \end{flushleft}
+%    In other words, prepending \meta{something} with "\@HwM@auto@font@selector"
+%    turns it from something that requires the two arguments \meta{style
+%    selector}\meta{font selector} into something else that takes just the
+%    single argument \meta{style selector}: the appropriate \meta{font selector}
+%    will be automatically supplied (whence the name of this macro).
+%    \textbf{Beware:} the following is a simple implementation that relies on
+%    assignments and that is therefore \emph{not} purely expandable.
+%    \begin{macrocode}
+\newcommand*\@HwM@auto@font@selector[2]{%
+  \def\@tempa{#1}%
+  \edef\@tempb{%
+    \ifx\displaystyle #2%
+      \textfont
+    \else \ifx\textstyle #2%
+      \textfont
+    \else \ifx\scriptstyle #2%
+      \scriptfont
+    \else \ifx\scriptscriptstyle #2%
+      \scriptscriptfont
+    \fi\fi\fi\fi
+  }%
+  \expandafter \@tempa \expandafter #2\@tempb
+}
+%    \end{macrocode}
+%    \end{macro}
+%
+%    \textbf{Uncommented code} again.
+%    \begin{macrocode}
+\newcommand*\@HwM@extended@arrowfill@[2]{%
+  % #1 is the "leaders" (pseudo-)macro (must gobble 2 arguments)
+  % #2 is the minimal width in math units
+  \@HwM@auto@font@selector
+        {\@HwM@stylefont@arrowfill{#1}{#2}}%
+}
+\newcommand*\@HwM@stylefont@arrowfill[4]{%
+  % #1 is the "leaders" (pseudo-)macro (must gobble 2 arguments)
+  % #2 is the minimal width in math units
+  % #3 is style selector (e.g., "\displaystyle")
+  % #4 is font selector (e.g., "\textfont")
+  $\m@th
+    \thickmuskip 0mu%
+    \medmuskip  \thickmuskip
+    \thinmuskip \thickmuskip
+    \setlength\@HwM@arrowfill@skip
+        {#2\fontdimen 6 #4\tw@ \@plus \@ne fill}%
+    #3%
+    #1#3#4%
+  $%
+}
+\newcommand*\@HwM@enriched@arrowfill@[5]{%
+  % #1, #2, and #3 are the three characters
+  % #4 and #5 are the two additional macros (both with 2 arguments)
+  % its call must be followed by the argument for the minimal width
+  \@HwM@extended@arrowfill@
+        {\HwM@arrowfill@cleaders{#1}{#2}{#3}{#4}{#5}}%
+}
+\newcommand*\HwM@arrowfill@cleaders[7]{%
+  % #1, #2, and #3 are the three characters
+  % #4 and #5 are the two additional macros (both with 2 arguments)
+  % #6 is style selector (e.g., "\displaystyle")
+  % #7 is font selector (e.g., "\textfont")
+  #4#6#7%
+  \relax #1\mkern-7mu%
+  \cleaders\hbox{$#6\mkern-2mu#2\mkern-2mu$}\hskip\@HwM@arrowfill@skip
+  \mkern-7mu#3\relax
+  #5#6#7%
+}
+\newcommand*\@HwM@rightbroomfill@Wwac@{%
+  \@HwM@set@right@dir
+  \@HwM@enriched@arrowfill@ \ni\relbar\relbar
+        \@gobbletwo
+        \@HwM@right@add@witch@cat
+        \@ne
+}
+\newcommand*\@HwM@right@add@witch@cat[2]{%
+  \hskip -\glueexpr \@HwM@arrowfill@skip/\tw@ \relax
+  \@HwM@Small@Witch@Wo@Broom #2%
+  \if@HwM@cat@
+    \hskip \glueexpr \@HwM@arrowfill@skip/4 \relax
+    \@HwM@Small@Cat@On@Hori@Broom #2%
+    \hskip \glueexpr \@HwM@arrowfill@skip/4 \relax
+  \else
+    \hskip \glueexpr \@HwM@arrowfill@skip/\tw@ \relax
+  \fi
+}%
+\newcommand*\@HwM@leftbroomfill@Wwac@{%
+  \@HwM@set@left@dir
+  \@HwM@enriched@arrowfill@ \relbar\relbar\in
+        \@HwM@left@add@witch@cat
+        \@gobbletwo
+        \@ne
+}
+\newcommand*\@HwM@left@add@witch@cat[2]{%
+  \if@HwM@cat@
+    \hskip \glueexpr \@HwM@arrowfill@skip/4 \relax
+    \@HwM@Small@Cat@On@Hori@Broom #2%
+    \hskip \glueexpr \@HwM@arrowfill@skip/4 \relax
+  \else
+    \hskip \glueexpr \@HwM@arrowfill@skip/\tw@ \relax
+  \fi
+  \@HwM@Small@Witch@Wo@Broom #2%
+  \hskip -\glueexpr \@HwM@arrowfill@skip/\tw@ \relax
+}
+\newcommand*\@HwM@init@swish@dimens[1]{%
+  \dimen4 \glueexpr \fontdimen 22 #1\tw@ *\tw@/\thr@@
+  \dimen6 .25\@HwM@thickness@units@for #1%
+  \dimen@ \dimen4
+  \@HwM@calc@swish@thickness
+}
+\newcommand*\@HwM@calc@swish@thickness{%
+  \dimen@ii -\dimen@
+  \advance \dimen@ii \dimen6
+}
+\newcommand*\@HwM@swish@leaders{%
+  \leaders \hrule \@height\dimen@ \@depth\dimen@ii \hskip
+}
+\newcommand*\@HwM@right@ghost@swish[2]{%
+  \@HwM@init@swish@dimens #2%
+  \hskip \glueexpr \@HwM@arrowfill@skip/4\relax
+  \@HwM@swish@leaders \glueexpr \@HwM@arrowfill@skip/4\relax
+  \hskip \glueexpr \@HwM@arrowfill@skip/8\relax
+  \@HwM@swish@leaders \glueexpr \@HwM@arrowfill@skip*\thr@@/8\relax
+  \hskip -\@HwM@arrowfill@skip
+  \advance \dimen@ \dimen4
+  \@HwM@calc@swish@thickness
+  \@HwM@swish@leaders \glueexpr \@HwM@arrowfill@skip*\thr@@/4 \relax
+  \hskip \glueexpr \@HwM@arrowfill@skip/8\relax
+  \@HwM@swish@leaders
+        \glueexpr \@HwM@arrowfill@skip/8+\dimen4 /\tw@ \relax
+  \hskip -\glueexpr \@HwM@arrowfill@skip/\tw@ \relax
+  \advance \dimen@ \dimen4
+  \@HwM@calc@swish@thickness
+  \@HwM@swish@leaders
+        \glueexpr \@HwM@arrowfill@skip/\tw@ +\dimen4 /\tw@ \relax
+  \kern -\dimen4
+  \mathrightghost
+}
+\newcommand*\@HwM@left@ghost@swish[2]{%
+  \mathleftghost
+  \@HwM@init@swish@dimens #2%
+  \@HwM@swish@leaders \glueexpr \@HwM@arrowfill@skip*\thr@@/8\relax
+  \hskip \glueexpr \@HwM@arrowfill@skip/8\relax
+  \@HwM@swish@leaders \glueexpr \@HwM@arrowfill@skip/4\relax
+  \hskip -\glueexpr \@HwM@arrowfill@skip*\thr@@/4+\dimen4 /\tw@ \relax
+  \advance \dimen@ \dimen4
+  \@HwM@calc@swish@thickness
+  \@HwM@swish@leaders
+        \glueexpr \@HwM@arrowfill@skip/8+\dimen4 /\tw@\relax
+  \hskip \glueexpr \@HwM@arrowfill@skip/8\relax
+  \@HwM@swish@leaders \glueexpr \@HwM@arrowfill@skip*\thr@@/4\relax
+  \hskip -\glueexpr \@HwM@arrowfill@skip +\dimen4 \relax
+  \advance \dimen@ \dimen4
+  \@HwM@calc@swish@thickness
+  \@HwM@swish@leaders
+        \glueexpr \@HwM@arrowfill@skip/\tw@ +\dimen4 /\tw@ \relax
+  \hskip \glueexpr \@HwM@arrowfill@skip/\tw@ +\dimen4 /\tw@ \relax
+}
+\newcommand*\@HwM@rightghostfill@{%
+  \@HwM@extended@arrowfill@ \@HwM@right@ghost@swish {.5}%
+}
+\newcommand*\@HwM@leftghostfill@{%
+  \@HwM@extended@arrowfill@ \@HwM@left@ghost@swish {.5}%
+}
+
+% three versions of "\mathpalette" adapted to our needs:
+\newcommand*\@HwM@dblstyle@mathpalette[2]{%
+  % Works like "\mathpalette", but macro passed in #1 must take
+  % (at least) three arguments, of which the first _two_ are
+  % style selections.
+  \mathchoice
+    {#1\displaystyle      \scriptstyle       {#2}}%
+    {#1\textstyle         \scriptstyle       {#2}}%
+    {#1\scriptstyle       \scriptscriptstyle {#2}}%
+    {#1\scriptscriptstyle \scriptscriptstyle {#2}}%
+}
+\newcommand*\@HwM@variable@mathpalette[2]{%
+  \mathchoice
+      {#1}%
+      {#2\textstyle         \textfont        }%
+      {#2\scriptstyle       \scriptfont      }%
+      {#2\scriptscriptstyle \scriptscriptfont}%
+}
+\newcommand*\@HwM@constant@mathpalette[1]{%
+  \mathchoice
+      {#1\displaystyle      \textfont        }%
+      {#1\textstyle         \textfont        }%
+      {#1\scriptstyle       \scriptfont      }%
+      {#1\scriptscriptstyle \scriptscriptfont}%
+}
+
+% General calls:
+\newcommand*\@HwM@general@large@operator[2]{%
+  \mathop{%
+    \@HwM@variable@mathpalette{#1}{#2}%
+  }\slimits@
+}
+\newcommand*\@HwM@general@inner@symbol[2]{%
+  \mathinner{%
+    \@HwM@variable@mathpalette{#1}{#2}%
+  }%
+}
+\newcommand*\@HwM@general@binary@operation[1]{%
+  \mathbin{%
+    \@HwM@constant@mathpalette{#1}%
+  }%
+}
+\newcommand*\@HwM@general@ordinary@symbol[1]{%
+  \mathord{%
+    \@HwM@constant@mathpalette{#1}%
+  }%
+}
+\newcommand*\@HwM@ifstar@cat[1]{%
+    \@ifstar
+        {\@HwM@cat@true  #1}%
+        {\@HwM@cat@false #1}%
+}
+
+%
+% User-level commands:
+\newcommand*\mathwitch{%
+  \DOTSB
+  \@HwM@set@right@dir
+  \@HwM@ifstar@cat{\@HwM@mathwitch lr}%
+}
+\newcommand*\reversemathwitch{%
+  \DOTSB
+  \@HwM@set@left@dir
+  \@HwM@ifstar@cat{\@HwM@mathwitch rl}%
+}
+\newcommand*\@HwM@mathwitch[2]{%
+  \@HwM@general@large@operator {\@HwM@Large@Witch #1#2}\@HwM@Small@Witch
+}
+
+\newcommand*\pumpkin{%
+  \DOTSB
+  \@HwM@general@binary@operation \@HwM@Oplus@Pumpkin
+}
+\newcommand*\bigpumpkin{%
+  \DOTSB
+  \@HwM@general@large@operator \@HwM@Large@Pumpkin \@HwM@Small@Pumpkin
+}
+\@ifdefinable\greatpumpkin{\let\greatpumpkin=\bigpumpkin}
+
+\newcommand*\mathcloud       {\@HwM@set@right@dir \@HwM@mathcloud}
+\newcommand*\reversemathcloud{\@HwM@set@left@dir  \@HwM@mathcloud}
+\newcommand*\@HwM@mathcloud{%
+  \@HwM@general@inner@symbol \@HwM@Large@Cloud \@HwM@Small@Cloud
+}
+
+\newcommand*\mathghost{%
+  \@HwM@general@ordinary@symbol \@HwM@Symmetric@Ghost
+}
+\newcommand*\mathrightghost{\@HwM@set@right@dir \@HwM@mathghost}
+\newcommand*\mathleftghost {\@HwM@set@left@dir  \@HwM@mathghost}
+\newcommand*\@HwM@mathghost{%
+  \@HwM@general@ordinary@symbol \@HwM@Asymmetric@Ghost
+}
+%
+% Accents.
+\newcommand*\@HwM@dblstyle@overarrow@[4]{%
+  % #1 := stretchable covering arrow
+  % #2 := base style
+  % #3 := style for covering arrow
+  % #4 := base symbol
+  \vbox{\ialign{##\crcr
+    #1#3\crcr
+    \noalign{\nointerlineskip}%
+    $\m@th\hfil #2#4\hfil$\crcr
+  }}%
+}
+\newcommand*\@HwM@dblstyle@underarrow@[4]{%
+  % #1 := stretchable underlying arrow
+  % #2 := base style
+  % #3 := style for underlying arrow
+  % #4 := base symbol
+  \vtop{\ialign{##\crcr
+    $\m@th\hfil #2#4\hfil$\crcr
+    \noalign{\nointerlineskip \kern\ex@}%
+    #1#3\crcr
+  }}%
+}
+\newcommand*\@HwM@general@ou@w@cat[1]{%
+  \@HwM@ifstar@cat{\@HwM@dblstyle@mathpalette{#1}}%
+}
+\newcommand*\overrightwitchonbroom{%
+  \@HwM@general@ou@w@cat
+    {\@HwM@dblstyle@overarrow@ \@HwM@rightbroomfill@Wwac@}%
+}
+\newcommand*\overleftwitchonbroom{%
+  \@HwM@general@ou@w@cat
+    {\@HwM@dblstyle@overarrow@ \@HwM@leftbroomfill@Wwac@}%
+}
+\newcommand*\overrightswishingghost{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@overarrow@ \@HwM@rightghostfill@}%
+}
+\newcommand*\overleftswishingghost{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@overarrow@ \@HwM@leftghostfill@}%
+}
+\newcommand*\underrightwitchonbroom{%
+  \@HwM@general@ou@w@cat
+    {\@HwM@dblstyle@underarrow@ \@HwM@rightbroomfill@Wwac@}%
+}
+\newcommand*\underleftwitchonbroom{%
+  \@HwM@general@ou@w@cat
+    {\@HwM@dblstyle@underarrow@ \@HwM@leftbroomfill@Wwac@}%
+}
+\newcommand*\underrightswishingghost{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@underarrow@ \@HwM@rightghostfill@}%
+}
+\newcommand*\underleftswishingghost{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@underarrow@ \@HwM@leftghostfill@}%
+}
+%
+% The script version of standard over/under arrows.
+\newcommand*\overscriptrightarrow{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@overarrow@ \rightarrowfill@}%
+}
+\newcommand*\overscriptleftarrow{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@overarrow@ \leftarrowfill@}%
+}
+\newcommand*\overscriptleftrightarrow{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@overarrow@ \leftrightarrowfill@}%
+}
+\newcommand*\underscriptrightarrow{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@underarrow@ \rightarrowfill@}%
+}
+\newcommand*\underscriptleftarrow{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@underarrow@ \leftarrowfill@}%
+}
+\newcommand*\underscriptleftrightarrow{%
+  \@HwM@dblstyle@mathpalette
+    {\@HwM@dblstyle@underarrow@ \leftrightarrowfill@}%
+}
+%
+% Extensible "arrow-like" symbols.
+\newcommand*\@HwM@ext@arrow@w@cat[5]{%
+  \def\@HwM@tempa{\ext@arrow {#1}{#2}{#3}{#4}{#5}}%
+  \@HwM@ifstar@cat{\@HwM@ext@arrow@w@cat@x}%
+}
+\newcommand*\@HwM@ext@arrow@w@cat@x[2][]{%
+  \@HwM@tempa {#1}{#2}%
+}
+\newcommand*\xrightwitchonbroom{%
+  \@HwM@ext@arrow@w@cat 9395\@HwM@rightbroomfill@Wwac@%
+}
+\newcommand*\xleftwitchonbroom{%
+  \@HwM@ext@arrow@w@cat 3959\@HwM@leftbroomfill@Wwac@%
+}
+\newcommand*\xrightswishingghost[2][]{%
+  \ext@arrow 3{12}5{15}\@HwM@rightghostfill@{#1}{#2}%
+}
+\newcommand*\xleftswishingghost[2][]{%
+  \ext@arrow {12}3{15}5\@HwM@leftghostfill@{#1}{#2}%
+}
+%    \end{macrocode}
+%
+%    End of the module for the \packlass{\halloweenmath} package.
+%    \begin{macrocode}
+%</halloweenmath>
+%    \end{macrocode}
+%
+% \section{End of input}
+%
+%    The usual "\endinput" which prevents the \DS\ program from putting
+%    garbage into the generated files.
+%    \begin{macrocode}
+\endinput
+%    \end{macrocode}
+%
+% \Finale
+%