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authorNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
committerNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
commite0c6872cf40896c7be36b11dcc744620f10adf1d (patch)
tree60335e10d2f4354b0674ec22d7b53f0f8abee672 /macros/latex/contrib/halloweenmath
Initial commit
Diffstat (limited to 'macros/latex/contrib/halloweenmath')
-rw-r--r--macros/latex/contrib/halloweenmath/00readme.txt252
-rw-r--r--macros/latex/contrib/halloweenmath/Makefile147
-rw-r--r--macros/latex/contrib/halloweenmath/README30
-rw-r--r--macros/latex/contrib/halloweenmath/halloweenmath-doc.pdfbin0 -> 335762 bytes
-rw-r--r--macros/latex/contrib/halloweenmath/halloweenmath-man.pdfbin0 -> 540738 bytes
-rw-r--r--macros/latex/contrib/halloweenmath/halloweenmath-man.tex1068
-rw-r--r--macros/latex/contrib/halloweenmath/halloweenmath.dtx4928
-rw-r--r--macros/latex/contrib/halloweenmath/halloweenmath.ins174
-rw-r--r--macros/latex/contrib/halloweenmath/manifest.txt100
9 files changed, 6699 insertions, 0 deletions
diff --git a/macros/latex/contrib/halloweenmath/00readme.txt b/macros/latex/contrib/halloweenmath/00readme.txt
new file mode 100644
index 0000000000..9062c54982
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/00readme.txt
@@ -0,0 +1,252 @@
+
+This is file `00readme.txt'.
+(Start your first tour of the halloweenmath package by reading this file.)
+
+This file is part of a work named "halloweenmath package".
+
+Copyright (C) 2017 by Gustavo MEZZETTI.
+
+The 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
+ 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.
+
+This file, after giving a brief description of the halloweenmath
+package, explains how to install it and how to generate its--alas, still
+incomplete!--documentation.
+
+April 25, 2017 (vers. 0.10a)
+
+
+
+CONTENTS
+========
+
+- A dozen lines description of the software
+- Installation in a snapshot
+- Checking the contents of the distribution
+- How to install the halloweenmath package
+- How to generate the documentation
+- The makefile
+
+
+
+A DOZEN LINES DESCRIPTION OF THE SOFTWARE
+=========================================
+
+The halloweenmath package originated from a question asked for enjoyment
+on TeX-LaTeX Stack Exchange <http://tex.stackexchange.com> by the user
+cfr (see <http://tex.stackexchange.com/q/336768/69818>); it defines a
+handful of commands for typesetting mathematical symbols of various
+kinds, ranging from "large" operators to 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 (AmS-)LaTeX.
+
+
+
+INSTALLATION IN A SNAPSHOT
+==========================
+
+The halloweenmath package is distributed in the usual .dtx + .ins
+format. The main file is `halloweenmath.dtx', with installation script
+`halloweenmath.ins'. Do the usual things to install it and to generate
+the documentation. If you don't know what the usual things are, read
+below. Note that in order to generate the documentation you should do
+the following:
+
+latex; latex; makeindex (.idx); makeindex (.glo); latex; latex.
+
+
+
+CHECKING THE CONTENTS OF THE DISTRIBUTION
+=========================================
+
+Before installing the halloweenmath package and generating its
+documentation, it is a good idea to read the file `manifest.txt', which
+lists all the files that make up the distribution, to check that you
+don't lack any of them (in particular, that you have the file
+`manifest.txt' itself!). If you do find that some files are missing,
+don't hesitate to complain to the distributor from whom you obtained the
+others: this person, company, or institution is infringing the copyright
+(actually, the copyleft) of the halloweenmath package. Please remember,
+however, that in order to comply with the copyright a distributor is
+only requested to supply the files listed in `manifest.txt' under the
+title "MEANING OF THE TERM `Work'", but not those listed under "MEANING
+OF THE TERM `Compiled Work'".
+
+
+
+HOW TO INSTALL THE HALLOWEENMATH PACKAGE
+========================================
+
+Note that in many pre-packaged TeX distributions, like MikTeX and TeX
+Live, the halloweenmath package could be already installed, in which
+case you can use it straight away.
+
+If you need to install the halloweenmath package yourself, follow these
+steps (but also see the section titled "The makefile", below):
+
+1) Make sure that the files `halloweenmath.dtx' and `halloweenmath.ins'
+are placed in the same directory; below, we shall indicate this
+directory as "the current directory".
+
+2) Run LaTeX (or plain TeX) once on the file `halloweenmath.ins'. This
+will generate, in the current directory, the following LaTeX input file:
+
+ halloweenmath.sty
+
+3) Move the file listed in 2) from the current directory to a LaTeX
+input directory--see b) and c) below.
+
+4) If you wish, delete the file `halloweenmath.log' to save disk space.
+
+Installation is now finished! The following comments may be useful:
+
+a) 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 `halloweenmath.ins'.
+
+b) 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 hold your private classes and
+packages.
+
+c) If you are not able to find the LaTeX input directories, or you are
+not allowed to modify them and cannot create your personal LaTeX input
+directories, do this: place all the files listed under 2) above in any
+directory of your choice (a newly created, empty directory would be the
+best choice, however); then put all the LaTeX source files that you want
+to typeset using the halloweenmath package in that same directory. Of
+course, this solution becomes impractical if the number of such source
+files exceeds a dozen or so; but for a few files you can do this way, at
+least until you decide to finally learn how to create your private LaTeX
+input directories! :-)
+
+d) You may also choose to install the halloweenmath package inside the
+main texmf tree of your TeX installation (as opposed to installing it
+inside a directory devoted to private classes and packages). In this
+case, note that the--now accepted--TDS-compliant location for the
+halloweenmath package, that is, the directory inside which you should
+put all the files listed in 2), is
+
+ $TEXMF/tex/latex/halloweenmath/
+
+The documentation, on the other hand, should be stored inside
+
+ $TEXMF/doc/latex/halloweenmath/
+
+Of course, in order to do so you must have appropriate access
+priviledges to the texmf tree of your site.
+
+
+
+HOW TO GENERATE THE DOCUMENTATION
+=================================
+
+A shortened form of the documentation, already typeset and packaged in
+PDF, is provided in the file `halloweenmath-doc.pdf' that you might have
+found on some sites (e.g., the CTAN sites). This file, however, is not
+part of the halloweenmath package and distributors are not requested to
+include it among the distributed files. Moreover, it does not contain
+any implementation notes (in which most users, though, are not at all
+interested).
+
+If the distributor from whom you obtained the halloweenmath package did
+not provide the file `halloweenmath-doc.pdf', or if you want the full
+documentation, complete with all the available implementation notes
+(but, alas, still unfinished for many respects), you can generate it
+following these steps (but also see the section titled "The makefile",
+below):
+
+1) Run LaTeX (_not_ plain TeX) _twice_ on the file `halloweenmath.dtx'.
+This, among other things, will generate the files `halloweenmath.idx'
+and `halloweenmath.glo' in the same directory as the file
+`halloweenmath.dtx'.
+
+2) Run MakeIndex on the file `halloweenmath.idx' obtained in 1), using
+the style file `gind.ist', which is part of the standard LaTeX
+distribution.
+
+3) Run MakeIndex on the file `halloweenmath.glo' obtained in 1), using
+the style file `gglo.ist', which is part of the standard LaTeX
+distribution, and specifying the file `halloweenmath.gls' as the output
+file.
+
+4) Run LaTeX _two_ more times on the file `halloweenmath.dtx'.
+
+5) If you wish, you can now delete the following files, to save disk
+space:
+
+ halloweenmath.aux
+ halloweenmath.glg
+ halloweenmath.glo
+ halloweenmath.gls
+ halloweenmath.hd
+ halloweenmath.idx
+ halloweenmath.ilg
+ halloweenmath.ind
+ halloweenmath.lof
+ halloweenmath.log
+ halloweenmath.out
+ halloweenmath.toc
+
+After step 4), you should get the documentation in DVI format in the
+file `halloweenmath.dvi', located in the same directory as
+`halloweenmath.dtx', with all indexes, table of contents, etc.
+correctly set.
+
+However, if you are neurotic (as I am) and have a fast computer, you
+could run LaTeX three or four times, instead of two, in step 1)... :-)
+
+Other LaTeX typesetting engines should work in the same way, perhaps
+producing the output in a different format; for example, you may use
+pdflatex in place of LaTeX to obtain the documentation in PDF.
+
+
+
+THE MAKEFILE
+============
+
+A (quite trivial!) makefile that "knows" how to produce the
+documentation is offered along with the halloweenmath package. Although
+it is not a required part of the distribution (as per LPPL), you may
+find that some distributors supply it all the same (I hope the CTAN
+sites will do so). With this makefile in the same directory as
+`halloweenmath.dtx', the shell command
+
+ make doc
+
+will take all the necessary actions to produce the full documentation
+(in PDF; the modifications you need to introduce into the makefile in
+order to obtain DVI output should be quite obvious, however).
+
+The same makefile can also be used to extract the "executable" package
+file: simply issue the command
+
+ make code
+
+at the shell prompt; whereas
+
+ make
+
+will _both_ extract the code _and_ typeset the documentation. Type
+
+ make help
+
+for more information.
+
+
+Have fun with the halloweenmath package!
+
diff --git a/macros/latex/contrib/halloweenmath/Makefile b/macros/latex/contrib/halloweenmath/Makefile
new file mode 100644
index 0000000000..14862e19a6
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/Makefile
@@ -0,0 +1,147 @@
+# makefile
+#
+# 2017 Apr 25
+#
+# Macro definitions
+#
+# - parameters:
+ROOT_NAME = halloweenmath
+# (the following need not be redefined, although it can be)
+BUNDLE_NAME = $(ROOT_NAME) package
+#
+# - all the rest:
+DTX_NAME = $(ROOT_NAME).dtx
+INS_NAME = $(ROOT_NAME).ins
+LOG_FILE = $(ROOT_NAME).log
+DOC_AUX_FIL = $(LOG_FILE) $(ROOT_NAME).aux \
+ $(ROOT_NAME).glo $(ROOT_NAME).gls \
+ $(ROOT_NAME).idx $(ROOT_NAME).ind \
+ $(ROOT_NAME).ilg $(ROOT_NAME).glg \
+ $(ROOT_NAME).toc $(ROOT_NAME).lof \
+ $(ROOT_NAME).hd $(ROOT_NAME).out
+DOCUM_FILE = $(ROOT_NAME).pdf
+CODE_FILES = $(ROOT_NAME).sty
+#
+LATEX = pdflatex
+MAKEINDEX = makeindex
+REMOVE = -rm
+
+#
+define GEN_FAKE_INDEX
+ @echo '\\begin{theindex}' > $(ROOT_NAME).ind
+ @echo '\\end{theindex}' >> $(ROOT_NAME).ind
+ @echo "Generating fake .ind file."
+endef
+#
+define GEN_FAKE_GLOSSARY
+ @echo '\\begin{theglossary}' > $(ROOT_NAME).gls
+ @echo '\\end{theglossary}' >> $(ROOT_NAME).gls
+ @echo "Generating fake .gls file."
+endef
+
+
+
+.PHONY: default
+.PHONY: code doc
+.PHONY: clean cleandoc cleanaux cleancode cleanlog cleanall
+.PHONY: help
+
+# Default target
+default: doc code
+
+# Generating the code
+################################################################
+# #
+# PLEASE NOTE THAT THE INSTALLER SCRIPT IS EXECUTED WITH #
+# openout_any=r #
+# #
+################################################################
+code:
+ openout_any=r tex $(INS_NAME)
+
+# Generating the documentation
+doc: $(DOCUM_FILE)
+
+$(DOCUM_FILE): $(DTX_NAME)
+# Hack for getting index and glossary in the toc since first run:
+ $(GEN_FAKE_INDEX)
+ $(GEN_FAKE_GLOSSARY)
+# We know how many runs are needed:
+ $(LATEX) $(DTX_NAME)
+ $(LATEX) $(DTX_NAME)
+ $(MAKEINDEX) -s gind.ist -t $(ROOT_NAME).ilg -o $(ROOT_NAME).ind \
+ $(ROOT_NAME).idx
+ $(MAKEINDEX) -s gglo.ist -t $(ROOT_NAME).glg -o $(ROOT_NAME).gls \
+ $(ROOT_NAME).glo
+ $(LATEX) $(DTX_NAME)
+ $(LATEX) $(DTX_NAME)
+# Hyperlinks in the indexes seem not to work properly without the
+# following additional run:
+ $(MAKEINDEX) -s gind.ist -t $(ROOT_NAME).ilg -o $(ROOT_NAME).ind \
+ $(ROOT_NAME).idx
+ $(MAKEINDEX) -s gglo.ist -t $(ROOT_NAME).glg -o $(ROOT_NAME).gls \
+ $(ROOT_NAME).glo
+ $(LATEX) $(DTX_NAME)
+
+# Cleaning up: command "make clean" defaults to "make cleanall"
+clean: cleanall
+
+# Cleaning the code files
+cleancode:
+ $(REMOVE) $(CODE_FILES)
+
+# Cleaning the documentation files
+cleandoc: cleanaux
+ $(REMOVE) $(DOCUM_FILE)
+
+# Cleaning just the auxiliary files used in producing the documentation
+cleanaux:
+ $(REMOVE) $(DOC_AUX_FIL)
+
+# Cleaning only the transcript file (e.g., after "make code")
+cleanlog:
+ $(REMOVE) $(LOG_FILE)
+
+# Cleaning up all the generated files
+cleanall: cleancode cleandoc
+
+# Giving help
+help:
+ @echo "Here is a list of the available commands:"
+ @echo
+ @echo " make"
+ @echo " Generate both the code and the documentation (see below)."
+ @echo
+ @echo " make code"
+ @echo " Generate all the LaTeX \"executables\" (e.g., \`.sty' files)"
+ @echo " of the $(BUNDLE_NAME);"
+ @echo " these files go into the LaTeX input directories."
+ @echo
+ @echo " make doc"
+ @echo " Generate the documentation (in PDF); the resulting PDF file"
+ @echo " goes into the LaTeX documentation directories (the auxiliary"
+ @echo " files may be discarded)."
+ @echo
+ @echo " make clean"
+ @echo " make cleanall"
+ @echo " These two commands are synonyms; they remove all of the"
+ @echo " generated files (both code and documentation)."
+ @echo
+ @echo " make cleancode"
+ @echo " Remove the LaTeX source files (the \"code files\")."
+ @echo
+ @echo " make cleandoc"
+ @echo " Remove the documentation, together with all the auxiliary"
+ @echo " files used to generate it."
+ @echo
+ @echo " make cleanaux"
+ @echo " Remove only the auxiliary files used to generate the"
+ @echo " documentation."
+ @echo
+ @echo " make cleanlog"
+ @echo " Remove just the transcript file (e.g., after \"make doc\")."
+ @echo
+ @echo " make help"
+ @echo " Print this help message."
+ @echo
+
diff --git a/macros/latex/contrib/halloweenmath/README b/macros/latex/contrib/halloweenmath/README
new file mode 100644
index 0000000000..f8ae0c7905
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/README
@@ -0,0 +1,30 @@
+(Version indicator: 2017 Apr 25)
+
+The halloweenmath package originated from a question asked for enjoyment
+on TeX-LaTeX Stack Exchange <http://tex.stackexchange.com> by the user
+cfr (see <http://tex.stackexchange.com/q/336768/69818>); it defines a
+handful of commands for typesetting mathematical symbols of various
+kinds, ranging from "large" operators to 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 (AmS-)LaTeX.
+
+The 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.
+
+For more information, read the following files:
+
+00readme.txt -- start by reading this file
+halloweenmath-doc.pdf -- overview of the halloweenmath package (PDF)
+halloweenmath-man.pdf -- user's manual for this same package (PDF)
+
+Other files that make up the distribution are:
+
+manifest.txt -- legal stuff
+halloweenmath.dtx -- main source file
+halloweenmath.ins -- installation script
+
+See the file `manifest.txt' for a more precise specification of what
+files constitutes a LPPL-compliant distribution.
diff --git a/macros/latex/contrib/halloweenmath/halloweenmath-doc.pdf b/macros/latex/contrib/halloweenmath/halloweenmath-doc.pdf
new file mode 100644
index 0000000000..94debdafad
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/halloweenmath-doc.pdf
Binary files differ
diff --git a/macros/latex/contrib/halloweenmath/halloweenmath-man.pdf b/macros/latex/contrib/halloweenmath/halloweenmath-man.pdf
new file mode 100644
index 0000000000..5b86c5fa77
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/halloweenmath-man.pdf
Binary files differ
diff --git a/macros/latex/contrib/halloweenmath/halloweenmath-man.tex b/macros/latex/contrib/halloweenmath/halloweenmath-man.tex
new file mode 100644
index 0000000000..7776ee16bd
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/halloweenmath-man.tex
@@ -0,0 +1,1068 @@
+\documentclass[a4paper]{article}
+\usepackage[T1]{fontenc}
+\usepackage{amsmath,amsfonts}
+\usepackage{halloweenmath}[2017/04/16]
+\usepackage{array}
+\usepackage[bookmarksnumbered]{hyperref}
+
+\title{User's manual\\for the \halloweenmath\ package}
+\author{G. Mezzetti}
+\date{April~25, 2017}
+
+\hypersetup{
+ pdftitle = {User's manual for the halloweenmath package},
+ pdfauthor = {G. Mezzetti},
+ pdfsubject = {The halloweenmath LaTeX package},
+ pdfkeywords = {TeX,LaTeX,Halloween,math,math symbold},
+ pdfcreationdate = {D:20170425120000},
+ pdfmoddate = {D:20170425120000}
+}
+
+\DeclareTextFontCommand{\packlass}{\normalfont\sffamily}
+\DeclareTextFontCommand{\opt} {\normalfont\ttfamily}
+\newcommand*{\meta}[1]{{\normalfont \(\langle\textit{#1}\rangle\)}}
+\newcommand*{\halloweenmath}{\packlass{halloweenmath}}
+\newcommand*{\amsmath} {\packlass{amsmath}}
+
+\newcommand*{\sumxn}{x_{1}+\dots+x_{n}}
+
+\makeatletter
+
+\newcolumntype{H}[3]{>{\hb@xt@ #3\bgroup#1}c<{#2\egroup}}
+\newcolumntype{U}[2]{H{\hss$#1}{$\hss}{#2}@{\hspace{.5em}}}
+\newcolumntype{V}[1]{H{\ttfamily}{\hss}{#1}}
+\newcolumntype{W}[1]{H{}{\hss}{#1}}
+\newcolumntype{O}{U{}{15\p@}}
+\newcolumntype{D}{U{\displaystyle}{30\p@}}
+\newcolumntype{L}{OD}
+\newcolumntype{A}{U{}{40\p@}}
+
+\newenvironment*{@symtable}[2]{\par
+ \centering
+ \addtolength\leftskip {-80\p@}%
+ \addtolength\rightskip{-80\p@}%
+ \setlength\arraycolsep{.5em}%
+ \tabular{@{}*{#2}{#1}@{}}%
+}{%
+ \endtabular
+ \par
+}
+\newenvironment{symtable}[1][\thr@@]{%
+ \@symtable{OV{90\p@}}{#1}%
+}{%
+ \end@symtable
+}
+\newenvironment{opsymtable}[1][\tw@]{%
+ \def\arraystretch{\tw@}%
+ \@symtable{LV{120\p@}}{#1}%
+}{%
+ \end@symtable
+}
+\newenvironment{xasymtable}[1][\tw@]{%
+ \def\arraystretch{\tw@}%
+ \@symtable{AW{200\p@}}{#1}%
+}{%
+ \end@symtable
+}
+\newcommand*\Sym[1] {#1&\string#1}
+\newcommand*\OpSym[1]{#1&#1&\string#1}
+
+\makeatother
+
+
+
+\begin{document}
+
+\maketitle
+
+\tableofcontents
+\listoftables
+
+
+
+\clearpage
+
+\section{Package loading}
+\label{S:Loading}
+
+Load the \halloweenmath\ package as any other \LaTeXe\ package, that is, via the
+usual \verb|\usepackage| declaration:
+\begin{verbatim}
+ \usepackage{halloweenmath}
+\end{verbatim}
+Note that the \halloweenmath\ package requires the \amsmath\ package, and loads
+it (without specifying any option) if it is not already loaded. If you want to
+pass options to \amsmath, load it before \halloweenmath.
+
+The \halloweenmath\ package defines no options by itself; nevertheless, it does
+honor the [\opt{no}]\opt{sumlimits} options from the \amsmath\ package.
+
+
+
+\section{Package usage}
+\label{S:Usage}
+
+The \halloweenmath\ package defines a handful of commands, all of which are
+intended for use \emph{in mathematical mode}, where they yield some kind of
+symbol that draws from the classic Halloween-related iconography (pumpkins,
+witches, ghosts, bats, and so on). Below, these symbols are grouped according
+to their mathematical ``r\^{o}le'' (ordinary symbols, binary operators,
+arrows\ldots).
+
+
+
+\subsection{Ordinary symbols}
+\label{sS:Ordinary}
+
+Table~\ref{tab:ordinary} lists the ordinary symbols provided by the
+\halloweenmath\ package.
+
+\begin{table}[t!p]
+ \centering
+ \begin{symtable}\relax
+ \Sym{\mathleftghost} & \Sym{\mathghost} & \Sym{\mathrightghost} \\
+ \Sym{\mathleftbat} & \Sym{\mathbat} & \Sym{\mathrightbat} \\
+ \end{symtable}
+ \caption{Ordinary symbols}
+ \label{tab:ordinary}
+\end{table}
+
+
+
+\subsection{Binary operators}
+\label{sS:Binary}
+
+Table~\ref{tab:binary} lists the binary operators available. Note that each
+binary operator has an associated ``large'' operator (see
+subsection~\ref{sS:Large}).
+
+\begin{table}[t!p]
+ \centering
+ \begin{symtable}[2]
+ \Sym{\pumpkin} & \Sym{\skull} \\
+ \end{symtable}
+ \caption{Binary operators}
+ \label{tab:binary}
+\end{table}
+
+
+
+\subsection{\textquotedblleft Large\textquotedblright\ operators}
+\label{sS:Large}
+
+Table~\ref{tab:large} lists the ``large'' operators. Each of them is depicted
+in two variants: the variant used for in-line math and the variant used for
+displayed formulas. In the table, besides the ``large'' operators called
+\verb|\bigpumpkin|\footnote{As a homage to Linus van Pelt,
+\texttt{\string\greatpumpkin} is defined as synonym of
+\texttt{\string\bigpumpkin}.} and \verb|\bigskull|, which are correlated to the
+binary operators \verb|\pumpkin| and \verb|\skull|, repectively, we find the
+commands \verb|\mathwitch| and \verb|\reversemathwitch|: note how these two last
+command have a \mbox{$*$-form} that adds a black cat on the broomstick.
+
+\begin{table}[t!p]
+ \centering
+ \begin{opsymtable}\relax
+ \OpSym{\mathwitch} & \OpSym{\reversemathwitch} \\
+ \OpSym{\mathwitch*} & \OpSym{\reversemathwitch*} \\
+ \OpSym{\bigpumpkin}\normalfont\footnotemark[\value{footnote}]
+ & \OpSym{\bigskull} \\
+ \end{opsymtable}
+ \caption{\textquotedblleft Large\textquotedblright\ operators}
+ \label{tab:large}
+\end{table}
+
+All the ``large'' operators listed in table~\ref{tab:large} honor the
+[\opt{no}]\opt{sumlimits} options from the \amsmath\ package.
+
+
+
+\subsection{\textquotedblleft Fraction-like\textquotedblright\ symbols}
+\label{sS:Inner}
+
+There are also two commands, listed on table~\ref{tab:inner}, that yield symbols
+that are somewhat similar to fractions, in that they grow in size when they are
+typeset in display style.\footnote{Another \TeX nical aspect of these commands
+is that they yield an atom of type Inner.} They are intended to denote
+an unspecified subformula that appears as a part of a larger one.
+
+\begin{table}[t!p]
+ \centering
+ \begin{opsymtable}\relax
+ \OpSym{\mathcloud} & \OpSym{\reversemathcloud} \\
+ \end{opsymtable}
+ \caption{\textquotedblleft Fraction-like\textquotedblright\ symbols}
+ \label{tab:inner}
+\end{table}
+
+
+
+\subsection{\textquotedblleft Arrow-like\textquotedblright\ symbols}
+\label{sS:Arrow}
+
+As we'll see in subsection~\ref{sS:XArrow}, the \halloweenmath\ package provides
+a series of commands whose usage parallels that of ``extensible arrows'' like
+\verb|\xrightarrow| or \verb|\xleftarrow|; but the symbols that those commands
+yield when used with an empty argument turn out to be too short, and it is for
+this reason that the \halloweenmath\ package also offers you the four commands
+you can see in table~\ref{tab:arrow}: they produce brooms, or pitchforks, having
+fixed length, which is approximately the same size of a
+\verb|\longrightarrow|~($\longrightarrow$). All of these symbols are treated as
+relations.
+
+\begin{table}[t!p]
+ \centering
+ \begin{symtable}[2]
+ \Sym{\leftbroom} & \Sym{\rightbroom} \\
+ \Sym{\hmleftpitchfork} & \Sym{\hmrightpitchfork} \\
+ \end{symtable}
+ \caption{\textquotedblleft Arrow-like\textquotedblright\ symbols}
+ \label{tab:arrow}
+\end{table}
+
+
+
+\subsection{Extensible \textquotedblleft arrow-like\textquotedblright\ symbols}
+\label{sS:XArrow}
+
+You are probably already familiar with the ``extensible arrows'' like
+$\xrightarrow{abc}$ and~$\xleftarrow{abc}$; for example, you probably know that
+the input
+\begin{verbatim}
+ \[
+ \bigoplus_{i=1}^{n} A_{i} \xrightarrow{f_{1}+\dots+f_{n}} B
+ \]
+\end{verbatim}
+produces this result:
+\[
+ \bigoplus_{i=1}^{n} A_{i} \xrightarrow{f_{1}+\dots+f_{n}} B
+\]
+The \halloweenmath\ package features a whole assortment of extensible symbols of
+this kind, which are listed in table~\ref{tab:xarrow}. For example, you could
+say
+\begin{verbatim}
+ \[
+ G \xrightswishingghost{h_{1}+\dots+h_{n}}
+ \bigpumpkin_{t=1}^{n} S_{t}
+ \]
+\end{verbatim}
+to get the following in print:
+\[
+ G \xrightswishingghost{h_{1}+\dots+h_{n}}
+ \bigpumpkin_{t=1}^{n} S_{t}
+\]
+
+\begin{table}[t!p]
+ \centering
+ \begin{xasymtable}\relax
+ \xleftwitchonbroom{abc\dots z}
+ & \verb|\xleftwitchonbroom{abc\dots z}| &
+ \xrightwitchonbroom{abc\dots z}
+ & \verb|\xrightwitchonbroom{abc\dots z}| \\
+ \xleftwitchonbroom*{abc\dots z}
+ & \verb|\xleftwitchonbroom*{abc\dots z}| &
+ \xrightwitchonbroom*{abc\dots z}
+ & \verb|\xrightwitchonbroom*{abc\dots z}| \\
+ \xleftwitchonpitchfork{abc\dots z}
+ & \verb|\xleftwitchonpitchfork{abc\dots z}| &
+ \xrightwitchonpitchfork{abc\dots z}
+ & \verb|\xrightwitchonpitchfork{abc\dots z}| \\
+ \xleftwitchonpitchfork*{abc\dots z}
+ & \verb|\xleftwitchonpitchfork*{abc\dots z}| &
+ \xrightwitchonpitchfork*{abc\dots z}
+ & \verb|\xrightwitchonpitchfork*{abc\dots z}| \\
+ \xleftbroom{abc\dots z}
+ & \verb|\xleftbroom{abc\dots z}| &
+ \xrightbroom{abc\dots z}
+ & \verb|\xrightbroom{abc\dots z}| \\
+ \xleftpitchfork{abc\dots z}
+ & \verb|\xleftpitchfork{abc\dots z}| &
+ \xrightpitchfork{abc\dots z}
+ & \verb|\xrightpitchfork{abc\dots z}| \\
+ \xleftswishingghost{abc\dots z}
+ & \verb|\xleftswishingghost{abc\dots z}| &
+ \xrightswishingghost{abc\dots z}
+ & \verb|\xrightswishingghost{abc\dots z}| \\
+ \xleftflutteringbat{abc\dots z}
+ & \verb|\xleftflutteringbat{abc\dots z}| &
+ \xrightflutteringbat{abc\dots z}
+ & \verb|\xrightflutteringbat{abc\dots z}| \\
+ \end{xasymtable}
+ \caption{Extensible \textquotedblleft arrow-like\textquotedblright\ symbols}
+ \label{tab:xarrow}
+\end{table}
+
+More generally, exactly as the commands \verb|\xleftarrow| and
+\verb|\xrightarrow|, on which they are modeled, all the commands listed in
+table~\ref{tab:xarrow} take one optional argument, in which you can specify a
+subscript, and one mandatory argument, where a---possibly empty---superscript
+must be indicated. For example,
+\begin{verbatim}
+ \[
+ A \xrightwitchonbroom*[abc\dots z]{f_{1}+\dots+f_{n}} B
+ \xrightwitchonbroom*{f_{1}+\dots+f_{n}} C
+ \xrightwitchonbroom*[abc\dots z]{} D
+ \]
+\end{verbatim}
+results in
+\[
+ A \xrightwitchonbroom*[abc\dots z]{f_{1}+\dots+f_{n}} B
+ \xrightwitchonbroom*{f_{1}+\dots+f_{n}} C
+ \xrightwitchonbroom*[abc\dots z]{} D
+\]
+
+Note that, also in this family of symbols, the commands that involve a witch all
+provide a \mbox{$*$-form} that adds a cat on the broom (or pitchfork).
+
+The commands listed above should not be confused with those presented in
+subsection~\ref{sS:OUArrow}.
+
+
+
+\subsection{Extensible \textquotedblleft over-\protect\slash
+ under-arrow-like\textquotedblright\ symbols}
+\label{sS:OUArrow}
+
+The commands dealt with in subsection~\ref{sS:XArrow} typeset an extensible
+``arrow-like'' symbol having some math above or below it. But the \amsmath\
+package also provides commands that act the other way around, that is, they put
+an arrow over, or under, some math, as in the case of
+\begin{verbatim}
+ \overrightarrow{x_{1}+\dots+x_{n}}
+\end{verbatim}
+that yields \( \overrightarrow{x_{1}+\dots+x_{n}} \). The \halloweenmath\
+package provides a whole bunch of commands like this, which are listed in
+table~\ref{tab:ouarrow}, and which all share the same syntax as the
+\verb|\overrightarrow| command.
+
+\begin{table}[t!p]
+ \centering
+ \begin{xasymtable}\relax
+ \overleftwitchonbroom{abc\dots z}
+ & \verb|\overleftwitchonbroom{abc\dots z}| &
+ \overrightwitchonbroom{abc\dots z}
+ & \verb|\overrightwitchonbroom{abc\dots z}| \\
+ \overleftwitchonbroom*{abc\dots z}
+ & \verb|\overleftwitchonbroom*{abc\dots z}| &
+ \overrightwitchonbroom*{abc\dots z}
+ & \verb|\overrightwitchonbroom*{abc\dots z}| \\
+ \overleftwitchonpitchfork{abc\dots z}
+ & \verb|\overleftwitchonpitchfork{abc\dots z}| &
+ \overrightwitchonpitchfork{abc\dots z}
+ & \verb|\overrightwitchonpitchfork{abc\dots z}| \\
+ \overleftwitchonpitchfork*{abc\dots z}
+ & \verb|\overleftwitchonpitchfork*{abc\dots z}| &
+ \overrightwitchonpitchfork*{abc\dots z}
+ & \verb|\overrightwitchonpitchfork*{abc\dots z}| \\
+ \overleftbroom{abc\dots z}
+ & \verb|\overleftbroom{abc\dots z}| &
+ \overrightbroom{abc\dots z}
+ & \verb|\overrightbroom{abc\dots z}| \\
+ \overscriptleftbroom{abc\dots z}
+ & \verb|\overscriptleftbroom{abc\dots z}| &
+ \overscriptrightbroom{abc\dots z}
+ & \verb|\overscriptrightbroom{abc\dots z}| \\
+ \overleftpitchfork{abc\dots z}
+ & \verb|\overleftpitchfork{abc\dots z}| &
+ \overrightpitchfork{abc\dots z}
+ & \verb|\overrightpitchfork{abc\dots z}| \\
+ \overscriptleftpitchfork{abc\dots z}
+ & \verb|\overscriptleftpitchfork{abc\dots z}| &
+ \overscriptrightpitchfork{abc\dots z}
+ & \verb|\overscriptrightpitchfork{abc\dots z}| \\
+ \overleftswishingghost{abc\dots z}
+ & \verb|\overleftswishingghost{abc\dots z}| &
+ \overrightswishingghost{abc\dots z}
+ & \verb|\overrightswishingghost{abc\dots z}| \\
+ \overleftflutteringbat{abc\dots z}
+ & \verb|\overleftflutteringbat{abc\dots z}| &
+ \overrightflutteringbat{abc\dots z}
+ & \verb|\overrightflutteringbat{abc\dots z}| \\
+ \underleftwitchonbroom{abc\dots z}
+ & \verb|\underleftwitchonbroom{abc\dots z}| &
+ \underrightwitchonbroom{abc\dots z}
+ & \verb|\underrightwitchonbroom{abc\dots z}| \\
+ \underleftwitchonbroom*{abc\dots z}
+ & \verb|\underleftwitchonbroom*{abc\dots z}| &
+ \underrightwitchonbroom*{abc\dots z}
+ & \verb|\underrightwitchonbroom*{abc\dots z}| \\
+ \underleftwitchonpitchfork{abc\dots z}
+ & \verb|\underleftwitchonpitchfork{abc\dots z}| &
+ \underrightwitchonpitchfork{abc\dots z}
+ & \verb|\underrightwitchonpitchfork{abc\dots z}| \\
+ \underleftwitchonpitchfork*{abc\dots z}
+ & \verb|\underleftwitchonpitchfork*{abc\dots z}| &
+ \underrightwitchonpitchfork*{abc\dots z}
+ & \verb|\underrightwitchonpitchfork*{abc\dots z}| \\
+ \underleftbroom{abc\dots z}
+ & \verb|\underleftbroom{abc\dots z}| &
+ \underrightbroom{abc\dots z}
+ & \verb|\underrightbroom{abc\dots z}| \\
+ \underscriptleftbroom{abc\dots z}
+ & \verb|\underscriptleftbroom{abc\dots z}| &
+ \underscriptrightbroom{abc\dots z}
+ & \verb|\underscriptrightbroom{abc\dots z}| \\
+ \underleftpitchfork{abc\dots z}
+ & \verb|\underleftpitchfork{abc\dots z}| &
+ \underrightpitchfork{abc\dots z}
+ & \verb|\underrightpitchfork{abc\dots z}| \\
+ \underscriptleftpitchfork{abc\dots z}
+ & \verb|\underscriptleftpitchfork{abc\dots z}| &
+ \underscriptrightpitchfork{abc\dots z}
+ & \verb|\underscriptrightpitchfork{abc\dots z}| \\
+ \underleftswishingghost{abc\dots z}
+ & \verb|\underleftswishingghost{abc\dots z}| &
+ \underrightswishingghost{abc\dots z}
+ & \verb|\underrightswishingghost{abc\dots z}| \\
+ \underleftflutteringbat{abc\dots z}
+ & \verb|\underleftflutteringbat{abc\dots z}| &
+ \underrightflutteringbat{abc\dots z}
+ & \verb|\underrightflutteringbat{abc\dots z}| \\
+ \end{xasymtable}
+ \caption{Extensible \textquotedblleft over-\protect\slash
+ under-arrow-like\textquotedblright\ symbols}
+ \label{tab:ouarrow}
+\end{table}
+
+Although they are not extensible, and are thus more similar to math accents, we
+have chosen to include in this subsection also the commands listed in
+table~\ref{tab:oubat}. They typeset a subformula either surmounted by the bat
+produced by \verb|\mathbat|, or with that symbol underneath. Their normal
+(\emph{i.e.}, unstarred) form pretends that the bat has zero width (but some
+height), whereas the starred variant takes the actual width of the bat be into
+account; for example, given the input
+\begin{verbatim}
+ \begin{align*}
+ &x+y+z && x+y+z \\
+ &x+\overbat{y}+z && x+\overbat*{y}+z
+ \end{align*}
+\end{verbatim}
+compare the spacing you get in the two columns of the output:
+\begin{align*}
+ &x+y+z && x+y+z \\
+ &x+\overbat{y}+z && x+\overbat*{y}+z
+\end{align*}
+
+\begin{table}[t!p]
+ \centering
+ \begin{xasymtable}\relax
+ \overbat{xyz} & \verb|\overbat{xyz}| &
+ \underbat{xyz} & \verb|\underbat{xyz}| \\
+ \end{xasymtable}
+ \caption{Over\protect\slash under bats}
+ \label{tab:oubat}
+\end{table}
+
+
+
+\subsection{Script-style versions of
+ \texorpdfstring{\amsmath}{amsmath}\textquoteright s
+ over\protect\slash under arrows}
+\label{sS:ScriptArrow}
+
+The commands listed in table~\ref{tab:scriptarrow} all produce an output similar
+to that of the corresponding \amsmath's command having the same name, but
+stripped of the \texttt{script} substring, with the only difference that the
+size of the arrow is smaller. More precisely, they use for the arrow the
+relative script size of the current size (that is, of the size in which their
+argument is typeset). For example, whilst \verb|\overrightarrow{x+y+z}| yields
+$\overrightarrow{x+y+z}$, \verb|\overscriptrightarrow{x+y+z}| results in
+$\overscriptrightarrow{x+y+z}$ (do you see the difference?), which, in the
+author's humble opinion, looks \emph{much} better.
+
+\begin{table}[t!p]
+ \centering
+ \begin{xasymtable}\relax
+ \overscriptleftarrow{abc\dots z}
+ & \verb|\overscriptleftarrow{abc\dots z}| &
+ \underscriptleftarrow{abc\dots z}
+ & \verb|\underscriptleftarrow{abc\dots z}| \\
+ \overscriptrightarrow{abc\dots z}
+ & \verb|\overscriptrightarrow{abc\dots z}| &
+ \underscriptrightarrow{abc\dots z}
+ & \verb|\underscriptrightarrow{abc\dots z}| \\
+ \overscriptleftrightarrow{abc\dots z}
+ & \verb|\overscriptleftrightarrow{abc\dots z}| &
+ \underscriptleftrightarrow{abc\dots z}
+ & \verb|\underscriptleftrightarrow{abc\dots z}| \\
+ \end{xasymtable}
+ \caption{Extensible over\protect\slash under arrows with reduced size}
+ \label{tab:scriptarrow}
+\end{table}
+
+
+
+\clearpage
+
+\section{Examples of use}
+\label{S:Example}
+
+This section illustrates the use of the commands provided by the \halloweenmath\
+package: by reading the source code for this document, you can see how the
+output presented below can be obtained.
+
+
+
+\subsection{Applying black magic}
+
+The $\mathwitch$~symbol was invented with the intent to provide a notation for
+the operation of applying black magic to a formula. Its applications range from
+simple reductions sometimes made by certain undergraduate freshmen, as in
+\[
+ \mathwitch 2\sin\frac{x}{2} = \sin x
+\]
+to key steps that permit to simplify greatly the proof of an otherwise totally
+impenetrable theorem, for example
+\[
+ \mathwitch\Bigl(
+ \sup\,\{\,p\in\mathbb{N}\mid \text{$p$ and $p+2$ are both prime}\,\}
+ \Bigr) = \infty
+\]
+Another way of denoting the same operation is to place the broom and the witch
+\emph{over} the relevant subformula:
+\[
+ \overrightwitchonbroom{
+ \sup\,\{\,p\in\mathbb{N}\mid \text{$p$ and $p+2$ are both prime}\,\}
+ } = \infty
+\]
+
+Different types of magic, that you might want to apply to a given formula, can
+be distinguished by adding a black cat on the broom: for example, a student
+could claim that
+\begin{align*}
+ \mathwitch 2x\sin x &= 2\sin x^{2}\\
+ \intertext{whereas, for another student,}
+ \mathwitch*2x\sin x &= \sin 3x
+\end{align*}
+
+
+
+\subsection{Monoids}
+
+Let $X$ be a non-empty set, and suppose there exists a map
+\begin{equation}
+ X\times X\longrightarrow X,\qquad
+ (x,y)\longmapsto P(x,y)=x\pumpkin y
+ \label{eq:Pdef}
+\end{equation}
+Suppose furthermore that this map satisfies the \textbf{associative property}
+\begin{equation}
+ \forall x\in X,\;\forall y\in X,\;\forall z\in X\qquad
+ x\pumpkin(y\pumpkin z) = (x\pumpkin y)\pumpkin z
+ \label{eq:Passoc}
+\end{equation}
+Then, the pair $(X,\pumpkin)$ is called a \textbf{semigroup}, and $\pumpkin$
+denotes its \textbf{operation}. If, in addition, there exists in~$X$ an
+element~$\mathghost$ with the property that
+\begin{equation}
+ \forall x\in X\qquad
+ \mathghost\pumpkin x = x = x\pumpkin\mathghost
+ \label{eq:Punit}
+\end{equation}
+the triple $(X,\pumpkin,\mathghost)$ is called a \textbf{monoid}, and the
+element~$\mathghost$ is called its \textbf{unit}. It is immediate to prove that
+the unit of a monoid is unique: indeed, if $\mathghost'$ is another element
+of~$X$ having the property~\eqref{eq:Punit}, then
+\[
+ \mathghost' = \mathghost'\pumpkin\mathghost = \mathghost
+\]
+(the first equality holds because \( \mathghost'\in X \) and
+$\mathghost$~satisfies~\eqref{eq:Punit}, and the second because \( \mathghost\in
+X \) and $\mathghost'$~satisfies~\eqref{eq:Punit}).
+
+Let $(X,\pumpkin,\mathghost)$ be a monoid. Since its operation~$\pumpkin$ is
+associative, we may set, for \( x,y,z\in X \),
+\[
+ x\pumpkin y\pumpkin z =_{\mathrm{def}}
+ (x\pumpkin y)\pumpkin z = x\pumpkin (y\pumpkin z)
+\]
+More generally, since the order in which the operations are performed doesn't
+matter, given $n$~elements \( x_{1},\dots,x_{n} \in X \), with \( n \in
+\mathbb{N} \), the result of
+\[
+ \bigpumpkin_{i=1}^{n} x_{i} = x_{1}\pumpkin\dots\pumpkin x_{n}
+\]
+is unambiguously defined (it being~$\mathghost$ if \( n=0 \)).
+
+A monoid $(X,\pumpkin,\mathghost)$ is said to be \textbf{commutative} if
+\begin{equation}
+ \forall x\in X,\;\forall y\in X\qquad
+ x\pumpkin y = y\pumpkin x
+ \label{eq:Pcomm}
+\end{equation}
+In this case, even the order of the \emph{operands} becomes irrelevant, so that,
+for any finite (possibly empty) set~$F$, the notation \( \bigpumpkin_{i\in F}
+x_{i} \) also acquires a meaning.
+
+
+
+\subsection{Applications induced on power sets}
+
+If $X$ is a set, we'll denote by~$\wp(X)$ the set of all subsets of~$X$, that is
+\[
+ \wp(X) = \{\,S:S\subseteq X\,\}
+\]
+
+Let \( f\colon A\longrightarrow B \) a function. Starting from~$f$, we can
+define two other functions \( f^{\mathrightbat} \colon \wp(A) \longrightarrow
+\wp(B) \) and \( f^{\mathleftbat} \colon \wp(B) \longrightarrow \wp(A) \) in the
+following way:
+\begin{alignat}{2}
+ &\text{for $X\subseteq A$,}\quad
+ &f^{\mathrightbat}(X) &= \{\,f(x):x\in X\,\} \\
+ &\text{for $Y\subseteq B$,}\quad
+ &f^{\mathleftbat}(Y) &= \{\,x\in A:f(x)\in Y\,\}
+\end{alignat}
+In the case of functions with long names, or with long descriptions, we'll also
+use a notation like \( \overrightflutteringbat{f_{1}+\dots+f_{n}} \) to mean the
+same thing as \( (f_{1}+\dots+f_{n})^{\mathrightbat} \).
+
+For example,
+\begin{align*}
+ \mathop{\overrightflutteringbat{\sin}}(\mathbb{R}) &= [-1,1] \\
+ \mathop{\overrightflutteringbat{\sin}}\bigl([0,\pi]\bigr) &= [0,1] \\
+ \mathop{\overleftflutteringbat{\arcsin}}
+ \Bigl(\bigl[0,\tfrac{\pi}{2}\bigr]\Bigr) &= [0,1] \\
+ \mathop{\overrightflutteringbat{\sin+\cos}}(\mathbb{R})
+ &= \bigl[-\sqrt{2},\sqrt{2}\,\bigr] \\
+ \mathop{\overleftflutteringbat{\log}}\bigl(\mathopen]-\infty,0]\bigr)
+ &= \mathopen]0,1]
+\end{align*}
+
+
+
+\subsection{A comprehensive test}
+
+A comparison between the ``standard'' and the ``script'' extensible over\slash
+under arrows:
+\begin{align*}
+ \overrightarrow{f_{1}+\dots+f_{n}}
+ &\neq\overscriptrightarrow{f_{1}+\dots+f_{n}} \\
+ \overleftarrow{f_{1}+\dots+f_{n}}
+ &\neq\overscriptleftarrow{f_{1}+\dots+f_{n}} \\
+ \overleftrightarrow{f_{1}+\dots+f_{n}}
+ &\neq\overscriptleftrightarrow{f_{1}+\dots+f_{n}} \\
+ \underrightarrow{f_{1}+\dots+f_{n}}
+ &\neq\underscriptrightarrow{f_{1}+\dots+f_{n}} \\
+ \underleftarrow{f_{1}+\dots+f_{n}}
+ &\neq\underscriptleftarrow{f_{1}+\dots+f_{n}} \\
+ \underleftrightarrow{f_{1}+\dots+f_{n}}
+ &\neq\underscriptleftrightarrow{f_{1}+\dots+f_{n}}
+\end{align*}
+
+\bigbreak
+
+A reduction my students are likely to make:
+\[\mathwitch \frac{\sin x}{s} = x\,\mathrm{in}\]
+The same reduction as an in-line formula:
+\(\mathwitch \frac{\sin x}{s} = x\,\mathrm{in}\).
+
+Now with limits:
+\[
+ \mathwitch_{i=1}^{n} \frac
+ {\text{$i$-th magic term}}
+ {\text{$2^{i}$-th wizardry}}
+\]
+And repeated in-line: \( \mathwitch_{i=1}^{n} x_{i}y_{i} \).
+
+The \texttt{bold} math version is honored:\mathversion{bold}
+\[
+ \mathwitch*
+ \genfrac{<}{>}{0pt}{}
+ {\textbf{something terribly}}{\textbf{complicated}}
+ = 0
+\]
+Compare it with \texttt{normal} math\mathversion{normal}:
+\[
+ \mathwitch*
+ \genfrac{<}{>}{0pt}{}
+ {\text{something terribly}}{\text{complicated}}
+ = 0
+\]
+In-line math comparison:
+{\boldmath $\mathwitch* f(x)$} versus $\mathwitch* f(x)$.
+
+There is also a left-facing witch:
+\[\reversemathwitch \frac{\sin x}{s} = x\,\mathrm{in}\]
+And here is the in-line version:
+\(\reversemathwitch \frac{\sin x}{s} = x\,\mathrm{in}\).
+
+Test for \verb|\dots|:
+\[
+ \mathwitch_{i_{1}=1}^{n_{1}} \dots \mathwitch_{i_{p}=1}^{n_{p}}
+ \frac
+ {\text{$i_{1}$-th magic factor}}
+ {\text{$2^{i_{1}}$-th wizardry}}
+ \pumpkin\dots\pumpkin
+ \frac
+ {\text{$i_{p}$-th magic factor}}
+ {\text{$2^{i_{p}}$-th wizardry}}
+\]
+And repeated in-line: \( \mathwitch\dots\mathwitch_{i=1}^{n} x_{i}y_{i} \).
+
+\bigbreak
+
+Now the pumpkins. First the \texttt{bold} math version:\mathversion{bold}:
+\[ \bigoplus_{h=1}^{m}\bigpumpkin_{k=1}^{n} P_{h,k} \]
+Then the \texttt{normal} one\mathversion{normal}:
+\[ \bigoplus_{h=1}^{m}\bigpumpkin_{k=1}^{n} P_{h,k} \]
+In-line math comparison:
+{\boldmath \( \bigpumpkin_{i=1}^{n} P_{i} \neq \bigoplus_{i=1}^{n} P_{i} \)}
+versus \( \bigpumpkin_{i=1}^{n} P_{i} \neq \bigoplus_{i=1}^{n} P_{i} \).
+
+Close test: {\boldmath $\bigoplus$}$\bigoplus$.
+And against the pumpkins:
+{\boldmath $\bigpumpkin$}$\bigpumpkin\bigoplus${\boldmath $\bigoplus$}.
+
+In-line, but with \verb|\limits|:
+\( \bigoplus\limits_{h=1}^{m}\bigpumpkin\limits_{k=1}^{n} P_{h,k} \).
+
+Binary: \( x\pumpkin y \neq x\oplus y \). And in display:
+\[ a\pumpkin\frac{x\pumpkin y}{x\oplus y}\otimes b \]
+Close test: {\boldmath $\oplus$}$\oplus$.
+And with the pumpkins too:
+{\boldmath $\pumpkin$}$\pumpkin\oplus${\boldmath $\oplus$}.
+
+In general,
+\[ \bigpumpkin_{i=1}^{n} P_{i} = P_{1}\pumpkin\dots\pumpkin P_{n} \]
+
+\begingroup
+
+\bfseries\boldmath
+
+The same in bold:
+\[ \bigpumpkin_{i=1}^{n} P_{i} = P_{1}\pumpkin\dots\pumpkin P_{n} \]
+
+\endgroup
+
+Other styles: \( \frac{x\pumpkin y}{2} \), exponent~$Z^{\pumpkin}$,
+subscript~$W_{\!x\pumpkin y}$, double script \( 2^{t_{x\pumpkin y}} \).
+
+\bigbreak
+
+Clouds. A hypothetical identity:
+\( \frac{\sin^{2}x + \cos^{2}x}{\cos^{2}x} = \mathcloud \).
+Now the same identity set in display:
+\[ \frac{\sin^{2}x + \cos^{2}x}{\cos^{2}x} = \mathcloud \]
+Now in smaller size: \( \frac{\sin x+\cos x}{\mathcloud} = 1 \).
+
+Specular clouds, \texttt{bold}\ldots\mathversion{bold}
+\[ \reversemathcloud \longleftrightarrow \mathcloud \]
+\ldots and in \texttt{normal} math.\mathversion{normal}
+\[ \reversemathcloud \longleftrightarrow \mathcloud \]
+In-line math comparison:
+{\boldmath \( \reversemathcloud \leftrightarrow \mathcloud \)}
+versus \( \reversemathcloud \leftrightarrow \mathcloud \).
+Abutting: {\boldmath $\mathcloud$}$\mathcloud$.
+
+\bigbreak
+
+Ghosts: \( \mathleftghost \mathghost \mathrightghost \mathghost \mathleftghost
+\mathghost \mathrightghost \). Now with letters: \( H \mathghost H \mathghost h
+\mathghost ab \mathghost f \mathghost wxy \mathghost \), and also \(
+2\mathghost^{3} + 5\mathleftghost^{\!2}-3\mathrightghost_{i} =
+12\mathrightghost_{j}^{4} \). Then, what about~$x^{2\mathghost}$ and \(
+z_{\!\mathrightghost+1} = z_{\!\mathrightghost}^{2} + z_{\mathghost} \)?
+
+In subscripts:
+\begin{align*}
+ F_{\mathghost+2} &= F_{\mathghost+1} + F_{\mathghost} \\
+ F_{\!\mathrightghost+2} &= F_{\!\mathrightghost+1} + F_{\!\mathrightghost}
+\end{align*}
+Another test: \( \mathghost | \mathrightghost | \mathghost | \mathleftghost |
+\mathghost | \mathrightghost | \mathghost | \mathleftghost | \mathghost \). We
+should also try this: \( \mathrightghost \mathleftghost \mathrightghost
+\mathleftghost \).
+
+Let us now compare ghosts set in normal math
+\( \mathrightghost \mathleftghost \mathghost \mathrightghost \mathleftghost \)
+with (a few words to push the bold ghosts to the right)
+{\bfseries\boldmath ghosts like these
+\( \mathrightghost \mathleftghost \mathghost \mathrightghost \mathleftghost \),
+which are set in bold math.}
+
+\bigbreak
+
+Extensible arrows:
+\begin{gather*}
+ A \xrightwitchonbroom[a]{\sumxn} B \xrightwitchonbroom{x+z}
+ C \xrightwitchonbroom{} D \\
+ A \xrightwitchonbroom*[a]{\sumxn} B \xrightwitchonbroom*{x+z}
+ C \xrightwitchonbroom*{} D \\
+ A \xleftwitchonbroom*[a]{\sumxn} B \xleftwitchonbroom*{x+z}
+ C \xleftwitchonbroom*{} D \\
+ A \xleftwitchonbroom[a]{\sumxn} B \xleftwitchonbroom{x+z}
+ C \xleftwitchonbroom{} D
+\end{gather*}
+And \( \overrightwitchonbroom*{\sumxn}=0 \) versus \(
+\overrightwitchonbroom{\sumxn}=0 \); or \( \overleftwitchonbroom*{\sumxn}=0 \)
+versus \( \overleftwitchonbroom{\sumxn}=0 \).
+
+\begingroup
+
+\bfseries \mathversion{bold}
+
+Now repeat in bold:
+\begin{gather*}
+ A \xrightwitchonbroom[a]{\sumxn} B \xrightwitchonbroom{x+z}
+ C \xrightwitchonbroom{} D \\
+ A \xrightwitchonbroom*[a]{\sumxn} B \xrightwitchonbroom*{x+z}
+ C \xrightwitchonbroom*{} D \\
+ A \xleftwitchonbroom*[a]{\sumxn} B \xleftwitchonbroom*{x+z}
+ C \xleftwitchonbroom*{} D \\
+ A \xleftwitchonbroom[a]{\sumxn} B \xleftwitchonbroom{x+z}
+ C \xleftwitchonbroom{} D
+\end{gather*}
+And \( \overrightwitchonbroom*{\sumxn}=0 \) versus \(
+\overrightwitchonbroom{\sumxn}=0 \); or \( \overleftwitchonbroom*{\sumxn}=0 \)
+versus \( \overleftwitchonbroom{\sumxn}=0 \).
+
+\endgroup
+
+Hovering ghosts: \( \overrightswishingghost{\sumxn}=0 \). I~wonder whether
+there is enough space left for the swishing ghost; let's try again:
+\( \overrightswishingghost{(\sumxn)y}=0 \)! Yes, it looks like there is enough
+room, although, of course, we cannot help the line spacing going awry. Also try
+\( \overrightswishingghost{\mathstrut} \).
+\begin{gather*}
+ A \xrightswishingghost[a]{\sumxn} B \xrightswishingghost{x+z} C
+ \xrightswishingghost{} D \\
+ A \xleftswishingghost[a]{\sumxn} B \xleftswishingghost{x+z} C
+ \xleftswishingghost{} D
+\end{gather*}
+Another hovering ghost: \( \overleftswishingghost{\sumxn}=0 \).
+Lorem ipsum dolor sit amet consectetur adipisci elit. Ulla rutrum, vel sivi sit
+anismus oret, rubi sitiunt silvae. Let's see how it looks like when the ghost
+hovers on a taller formula, as in \(
+\overrightswishingghost{H_{1}\oplus\dots\oplus H_{k}} \). Mmm, it's suboptimal,
+to say the least.\footnote{We'd better try \(
+\underleftswishingghost{y_{1}+\dots+y_{n}} \), too; well, this one looks good!}
+
+Under ``arrow-like'' symbols: \( \underleftswishingghost{\sumxn}=0 \) and \(
+\underrightswishingghost{x+y+z} \). There are \(
+\underleftwitchonbroom*{\sumxn}=0 \) and \( \underrightwitchonbroom*{x+y+z} \)
+as well.
+
+Compare \( A\xrightswishingghost{\sumxn} B \) with (add a few words to push it
+to the next line) {\bfseries\boldmath its bold version \(
+A\xrightswishingghost{\sumxn} B \).}
+
+\bigbreak
+
+Bats: $\mathbat${\boldmath $\mathbat$}. We are interested in seeing whether a
+bat affixed to a letter as an exponent causes the lines of a paragraph to be
+further apart than usual. Therefore, we now try~$f^{\mathbat}$, also
+{\bfseries\boldmath in bold~$f^{\mathbat}$,} then we type a few more words (just
+enough to obtain another typeset line or two) in order to see what happens. We
+need to look at the transcript file, to check the outcome of the following
+tracing commands.
+
+% \begingroup
+% \showboxbreadth = 1000
+% \showboxdepth = 0 % show just the lines, not their contents
+% \showlists
+% \endgroup
+
+Asymmetric bats: $\mathleftbat${\boldmath $\mathleftbat$}, and also
+$\mathrightbat${\boldmath $\mathrightbat$}. Exponents: this is \texttt{normal}
+math \( x^{\mathleftbat} \pumpkin y^{\mathrightbat} \), while
+{\bfseries\boldmath this is \texttt{bold} math \( x^{\mathleftbat} \pumpkin
+y^{\mathrightbat} \).} Do you note the difference? Let's try subscripts, too:
+\( f_{\mathleftbat} \pumpkin g_{\mathrightbat} \) versus {\bfseries\boldmath
+bold \( f_{\mathleftbat} \pumpkin g_{\mathrightbat} \).}
+Now, keep on repeating some silly text, just in order to fill up the paragraph
+with a sufficient number of lines. Now, keep on repeating some silly text, just
+in order to fill up the paragraph with a sufficient number of lines. Now, keep
+on repeating some silly text, just in order to fill up the paragraph with a
+sufficient number of lines. That's enough!
+
+Hovering bats: \( \overrightflutteringbat{\sumxn}=0 \). I~wonder whether there
+is enough space left for the swishing bat; let's try again:
+\( \overrightflutteringbat{(\sumxn)y}=0 \)! Yes, it looks like there is enough
+room (with the usual remark abut line spacing). Also try
+\( \overrightflutteringbat{\mathstrut} \).
+\begin{gather*}
+ A \xrightflutteringbat[a]{\sumxn} B \xrightflutteringbat{x+z}
+ C \xrightflutteringbat{} D \\
+ A \xleftflutteringbat[a]{\sumxn} B \xleftflutteringbat{x+z} C
+ \xleftflutteringbat{} D
+\end{gather*}
+Another hovering bat: \( \overleftflutteringbat{\sumxn}=0 \).
+
+Under ``arrow-like'' bats: \( \underleftflutteringbat{\sumxn}=0 \) and \(
+\underrightflutteringbat{x+y+z} \).
+
+Compare \( A\xrightflutteringbat{\sumxn} B \) with (add a few words to push it
+to the next line) {\bfseries\boldmath its bold version \(
+A\xrightflutteringbat{\sumxn} B \).}
+
+Test for checking the placement of the formulas that go over or under the
+fluttering bat:
+\begin{gather*}
+ A \xrightflutteringbat[\text{a long subscript}]{\text{a long superscript}} B
+ \xrightflutteringbat[\text{a long subscript}]{|} C
+ \xrightflutteringbat{|} D \xrightflutteringbat{} E \\
+ A \xleftflutteringbat[\text{a long subscript}]{\text{a long superscript}} B
+ \xleftflutteringbat[\text{a long subscript}]{|} C
+ \xleftflutteringbat{|} D \xleftflutteringbat{} E
+\end{gather*}
+I'd say it's now OK\@\ldots
+
+\bigbreak
+
+Extensible arrows with pitchfork:
+\begin{gather*}
+ A \xrightwitchonpitchfork[a]{\sumxn} B \xrightwitchonpitchfork{x+z} C
+ \xrightwitchonpitchfork{} D \\
+ A \xrightwitchonpitchfork*[a]{\sumxn} B \xrightwitchonpitchfork*{x+z} C
+ \xrightwitchonpitchfork*{} D \\
+ A \xleftwitchonpitchfork*[a]{\sumxn} B \xleftwitchonpitchfork*{x+z} C
+ \xleftwitchonpitchfork*{} D \\
+ A \xleftwitchonpitchfork[a]{\sumxn} B \xleftwitchonpitchfork{x+z} C
+ \xleftwitchonpitchfork{} D
+\end{gather*}
+And \( \overrightwitchonpitchfork*{\sumxn}=0 \) versus \(
+\overrightwitchonpitchfork{\sumxn}=0 \); or \(
+\overleftwitchonpitchfork*{\sumxn}=0 \) versus \(
+\overleftwitchonpitchfork{\sumxn}=0 \). There are \(
+\underleftwitchonpitchfork*{\sumxn}=0 \) and \(
+\underrightwitchonpitchfork*{x+y+z} \) as well.
+
+\begingroup
+
+\bfseries \mathversion{bold}
+
+Now again, but all in boldface:
+\begin{gather*}
+ A \xrightwitchonpitchfork[a]{\sumxn} B \xrightwitchonpitchfork{x+z} C
+ \xrightwitchonpitchfork{} D \\
+ A \xrightwitchonpitchfork*[a]{\sumxn} B \xrightwitchonpitchfork*{x+z} C
+ \xrightwitchonpitchfork*{} D \\
+ A \xleftwitchonpitchfork*[a]{\sumxn} B \xleftwitchonpitchfork*{x+z} C
+ \xleftwitchonpitchfork*{} D \\
+ A \xleftwitchonpitchfork[a]{\sumxn} B \xleftwitchonpitchfork{x+z} C
+ \xleftwitchonpitchfork{} D
+\end{gather*}
+And \( \overrightwitchonpitchfork*{\sumxn}=0 \) versus \(
+\overrightwitchonpitchfork{\sumxn}=0 \); or \(
+\overleftwitchonpitchfork*{\sumxn}=0 \) versus \(
+\overleftwitchonpitchfork{\sumxn}=0 \). There are \(
+\underleftwitchonpitchfork*{\sumxn}=0 \) and \(
+\underrightwitchonpitchfork*{x+y+z} \) as well.
+
+\endgroup
+
+The big table of the rest:
+\begin{align*}
+ A &\xrightbroom{\sumxn} B &
+ \overrightbroom {\sumxn} = 0 &&
+ \underrightbroom{\sumxn} = 0 \\
+ &&
+ \overscriptrightbroom {\sumxn} = 0 &&
+ \underscriptrightbroom{\sumxn} = 0 \\
+ A &\xleftbroom{\sumxn} B &
+ \overleftbroom {\sumxn} = 0 &&
+ \underleftbroom{\sumxn} = 0 \\
+ &&
+ \overscriptleftbroom {\sumxn} = 0 &&
+ \underscriptleftbroom{\sumxn} = 0 \\
+ A &\xrightpitchfork{\sumxn} B &
+ \overrightpitchfork {\sumxn} = 0 &&
+ \underrightpitchfork{\sumxn} = 0 \\
+ &&
+ \overscriptrightpitchfork {\sumxn} = 0 &&
+ \underscriptrightpitchfork{\sumxn} = 0 \\
+ A &\xleftpitchfork{\sumxn} B &
+ \overleftpitchfork {\sumxn} = 0 &&
+ \underleftpitchfork{\sumxn} = 0 \\
+ &&
+ \overscriptleftpitchfork {\sumxn} = 0 &&
+ \underscriptleftpitchfork{\sumxn} = 0 \\
+\end{align*}
+
+Now in bold\ldots\space No, please, seriously, just the examples for the minimal
+size: in \texttt{normal} math we show \( A \xrightbroom{} B \) and \( C
+\xleftpitchfork{} D \) and \( \overscriptrightbroom{} \) and \(
+\overscriptleftpitchfork{} \), which we now repeat {\bfseries\boldmath in
+\texttt{bold} math \( A \xrightbroom{} B \) and \( C \xleftpitchfork{} D \) and
+\( \overscriptrightbroom{} \) and \( \overscriptleftpitchfork{} \).} Mmmh, the
+minimal size seems way too narrow: is it the same for the standard arrows?
+Let's see:
+\begin{align*}
+ A &\xrightarrow{} B & \overrightarrow{} && \overscriptrightarrow{} \\
+ A &\xleftarrow {} B & \overleftarrow {} && \overscriptleftarrow {} \\
+ A &\xrightbroom{} B & \overrightbroom{} && \overscriptrightbroom{} \\
+ A &\xleftbroom {} B & \overleftbroom {} && \overscriptleftbroom {}
+\end{align*}
+Well, almost so, but the arrow tip is much more ``discrete''\ldots
+
+To cope with this problem, \verb|\rightbroom| and siblings have been introduced:
+for example, \( X\rightbroom Y \).
+
+A comparative table follows:
+\begin{align*}
+ A &\rightbroom B & C &\hmrightpitchfork D \\
+ A &\leftbroom B & C &\hmleftpitchfork D \\
+ A &\longrightarrow B & C &\Longrightarrow D \\
+ A &\longleftarrow B & C &\Longleftarrow D \\
+ A &\xrightwitchonbroom{} B & C &\xrightwitchonpitchfork{} D \\
+ A &\xleftwitchonbroom{} B & C &\xleftwitchonpitchfork{} D \\
+\end{align*}
+
+Finally, \( \overbat{y} + \underbat{x} + z = 0 \) versus \( \overbat*{y} +
+\underbat*{x} + z = 0 \), and also note that \( {\overbat{x}}_{2} \ne
+{\overbat*{x}}_{2} \). Oh, wait, we have to check {\bfseries\boldmath the bold
+version \( {\overbat{x}}_{2} \ne {\overbat*{x}}_{2} \)} too!
+
+\bigbreak
+
+We've now gotten to skulls.
+\[ A \xrightswishingghost{\mspace{100mu}} B \skull C \]
+
+Skulls are similar to pumpkins, and thus to \verb|\oplus|:
+\begin{gather*}
+ H_{1} \skull \dots \skull H_{n} \\
+ H_{1} \oplus \dots \oplus H_{n} \\
+ H_{1} \pumpkin \dots \pumpkin H_{n}
+\end{gather*}
+As you can see, though, the dimensions differ slightly:
+\( {\skull}{\oplus}{\pumpkin} \).
+Subscript: \( A_{x\skull y} \).
+Now the ``large'' operator version:
+\begin{align*}
+ \bigskull _{i=1}^{n} H_{i} &= H_{1} \skull \dots \skull H_{n} \\
+ \bigoplus _{i=1}^{n} H_{i} &= H_{1} \oplus \dots \oplus H_{n} \\
+ \bigpumpkin_{i=1}^{n} H_{i} &= H_{1} \pumpkin \dots \pumpkin H_{n}
+\end{align*}
+In-line: \( \bigskull_{i=1}^{n} H_{i} = H_{1}\skull\dots\skull H_{n} \).
+Example of close comparison: \( \bigoplus\bigskull\bigpumpkin X \).
+{\bfseries\boldmath Now repeat in bold: \( \bigskull_{i=1}^{n} H_{i} =
+H_{1}\skull\dots\skull H_{n} \).}
+
+Skulls look much gloomier than pumpkins: compare \( P\pumpkin U\pumpkin M = P \)
+with \( S\skull K\skull U = L\odot L \). Why did~I ever outline such a grim and
+dreary picture? The ``large operator'' variant, then, is truly dreadful! How
+could anybody write a formula like \( \bigskull_{i}\bigskull_{j} A_{i}\otimes
+B_{j} \)? How much cheerer is \( \bigpumpkin_{i}\bigpumpkin_{j} A_{i}\otimes
+B_{j} \)? And look at the displayed version:
+\[
+ \bigskull_{i=1}^{m}\bigskull_{j=1}^{n} A_{i}\otimes B_{j} \neq
+ \bigpumpkin_{i=1}^{m}\bigpumpkin_{j=1}^{n} A_{i}\otimes B_{j}
+\]
+
+Comparison between math versions: $x\skull y$ is normal math,
+{\bfseries\boldmath whereas $x\skull y$ is bold.} Similarly, \(
+\bigskull_{i-1}^{n} K_{i} = L \) is normal, {\bfseries\boldmath but \(
+\bigskull_{i-1}^{n} K_{i} = L \) is bold.} And now the displays: normal
+\[
+ \bigskull_{i=1}^{m}\bigskull_{j=1}^{n} A_{i}\otimes B_{j} \neq
+ \bigpumpkin_{i=1}^{m}\bigpumpkin_{j=1}^{n} A_{i}\otimes B_{j}
+\]
+versus {\bfseries\boldmath bold
+\[
+ \bigskull_{i=1}^{m}\bigskull_{j=1}^{n} A_{i}\otimes B_{j} \neq
+ \bigpumpkin_{i=1}^{m}\bigpumpkin_{j=1}^{n} A_{i}\otimes B_{j}
+\]
+math.} Back to the normal font.
+
+\end{document}
diff --git a/macros/latex/contrib/halloweenmath/halloweenmath.dtx b/macros/latex/contrib/halloweenmath/halloweenmath.dtx
new file mode 100644
index 0000000000..83e0f21fb0
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/halloweenmath.dtx
@@ -0,0 +1,4928 @@
+% \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{0.10a}
+% \def\filedate{2017/04/25}
+% \def\docdate {2017/04/25}
+% \def\doclongdate{April~25, 2017}
+%
+% \CheckSum{2259}
+%
+% \changes{0.01}{2017 Jan 06}{First writing of the code}
+% \changes{0.10}{2017 Apr 16}{Changed the look of the broom in the extensible
+% ``arrow-like'' symbols, but retained the old one in newly added pitchforks}
+% \changes{0.10}{2017 Apr 16}{Added bats (ordinary symbols and extensible
+% ``arrow-like'' series)}
+% \changes{0.10}{2017 Apr 16}{Added skulls (binary operators and ``large''
+% operators)}
+% \changes{0.10}{2017 Apr 16}{Added ``unwitched'' extensible brooms and
+% pitchforks}
+% \changes{0.10}{2017 Apr 16}{Added ``Boo'' options}
+%
+%% \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{\",\.,\@}
+% \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}}
+% \newcounter{paramlist}
+% \renewcommand*{\theparamlist}{^^A
+% \ifnum \value{paramlist}>\z@
+% \ifnum \value{paramlist}<10
+% \arabic{paramlist}^^A
+% \else
+% \@ctrerr
+% \fi
+% \fi
+% }
+% \newenvironment*{paramlist}{^^A
+% \setcounter{paramlist}\z@
+% \@beginparpenalty \@M \relax
+% \setlength\topsep{\z@}^^A
+% \tabbing
+% \(\mbox{\#0}\leftarrow {\,}\)\=\kill
+% }{^^A
+% \endtabbing
+% }
+% \newcommand*{\param}{^^A
+% \stepcounter{paramlist}^^A
+% \(\mbox{\#\theparamlist}\leftarrow{}\)\>^^A
+% }
+% \newenvironment*{tightitemize}{^^A
+% \itemize
+% \setlength\topsep{\p@ \@plus\p@}^^A
+% \setlength\partopsep{\z@}^^A
+% \setlength\itemsep{\p@}^^A
+% \setlength\parsep{\z@ \@plus\p@}^^A
+% \setlength\parskip{\parsep}^^A
+% \setlength\@topsepadd{\topsep}^^A
+% \setlength\@topsep{\@topsepadd}^^A
+% }{\enditemize}
+% \newcommand{\@no@imp@StopEventually}[1]{#1\endinput}
+% \newcommand*{\IfImplementation}{%
+% \ifx \StopEventually \@no@imp@StopEventually
+% \expandafter\@secondoftwo
+% \else
+% \expandafter\@firstoftwo
+% \fi
+% }
+% \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}}
+% ^^A REMEMBER: "\DeclareTextFontCommand" can be used only in preamble!
+% \DeclareRobustCommand*{\packlass}[1]{{\normalfont\sffamily #1}}
+% \DeclareRobustCommand*{\filedir} [1]{{\normalfont\ttfamily #1}}
+% \DeclareRobustCommand*{\env}[1]{{\normalfont\ttfamily #1}}
+% ^^A \DeclareRobustCommand*{\ctr}[]{{\normalfont\ttfamily #1}}
+% \DeclareRobustCommand*{\opt}[1]{{\normalfont\ttfamily #1}}
+% \newcommand*{\sopt}[1]{\mbox{\opt{#1}}\optuseindex{#1}}
+% \newcommand*{\binvert}{\mathbin{|}}
+% \DeclareRobustCommand*{\TeXSXFullName}{^^A
+% \TeX \kern .13333em --\,\LaTeX\ Stack Exchange^^A
+% }
+% \DeclareRobustCommand*{\TeXSXAbbrev}{\TeX.SX\@}
+% \DeclareRobustCommand*{\TeXSXuser}[1]{{\normalfont\sffamily #1}}
+% \DeclareRobustCommand*{\TeXtok}[1]{\mbox{$\langle$#1\/$\rangle$}}
+% \newcommand*{\cfr}{\TeXSXuser{cfr}}
+% \newcommand*{\eg}{\emph{e.g.}, } ^^A note the space at the end
+%
+% \providecommand*{\href}[3][]{#3}
+% \providecommand*{\pdfbookmark}[3][]{}
+% \providecommand*{\nolinkurl}[1]{\url{#1}} ^^A if hyperref isn't loades,
+% ^^A hand over to url package
+% \providecommand*{\hypersetup}{}
+%
+% \addtolength{\marginparwidth}{2pt}
+%
+% \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
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+% \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:20170425120000},
+% pdfmoddate = {D:20170425120000},
+% 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{https://tex.stackexchange.com/}{\emph{\TeXSXFullName}}
+% (see~\cite{bib:cfr}) by the user
+% \href{https://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}
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+% \put(-4.1,-.8){\magicstar{.8}}
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+% \Line(.2,2.8)(.6,3)
+% \polygon*(-1,2)(-2,0)(-2,-1)(-1.5,-2)(1,-2)
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+% (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)
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+% \Line(1.7,1.6)(1.9,1.4)
+% \Line(1.7,1.6)(1.7,1.3)
+% ^^A
+% ^^A The cat:
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+% \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}
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+% \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
+% \IfImplementation{\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{https://tex.stackexchange.com/users/39222/cfr}{\cfr} asked a
+% question~\cite{bib:cfr} on the
+% \href{https://tex.stackexchange.com/}{\emph{\TeXSXFullName} 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. Well, 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
+% fluttering bats, skulls, and 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{https://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{https://tex.stackexchange.com/users/81905/guilherme-zanotelli}{\TeXSXuser{Guilherme
+% Zanotelli}} then
+% \href{https://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\footnote{Indeed, the first version of this package was
+% released on January~6, 2017.}
+%
+% \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.
+%
+% In this release too, alas, I~have to ask to be excused for not having
+% completed the comments in the \emph{Implementation} part. Some~35\% of the
+% code is still uncommented, and, as I~had already said in the
+% \emph{Introduction} to version~0.01, at present I~cannot yet make any
+% reliable guess as to when (or even if!\@) I'll be able to finish the work.
+% It is precisely for this reason that I~decided to release it in this
+% incomplete form, to avoid deferring indefinitely the availability of the
+% new, horrifying features that this version introduces.
+%
+%
+%
+% \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}.
+%
+% \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}
+% \label{ssS: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}
+% \label{ssS:Witches}
+%
+% 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, \eg "\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{\xrightwitchonpitchfork}
+% \DescribeMacro{\xleftwitchonpitchfork}
+% In version~0.01 of this package, the "\x"$\,*\,$"witchonbroom" commands
+% drew under the witch a ``broom'' that, actually, looked more like a
+% pitchfork (\TeXSXuser{cfr} had already complained about this in
+% \href{https://tex.stackexchange.com/questions/336768/seasonal-challenge-contributions-from-texing-dead-welcome#comment829686_337719}{one
+% of her comments} to my original answer on \TeXSXAbbrev); in the present
+% version this has been corrected, but the output produced by the first
+% version (which I~liked) can still be obtained by means of these two
+% commands, whose name is, indeed, more appropriate to the look of the
+% symbols they yield. Obviously, their syntax remains identical, \eg
+% \begin{flushleft}
+% \cmd{\xleftwitchonpitchfork}\oarg{under text}\marg{over text}
+% \end{flushleft}
+%
+% \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, \eg "\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}.}
+% \DescribeMacro{\overrightwitchonpitchfork}
+% \DescribeMacro{\overleftwitchonpitchfork}
+% \DescribeMacro{\underrightwitchonpitchfork}
+% \DescribeMacro{\underleftwitchonpitchfork}
+% Also in this case, the look of the symbols they draw has changed since
+% version~0.01 of this package, but the old shapes have been kept available
+% under different, and more appropriate, names: just use
+% \begin{flushleft}
+% "\overrightwitchonpitchfork "\marg{subformula} \\
+% "\overleftwitchonpitchfork "\marg{subformula} \\
+% "\underrightwitchonpitchfork"\marg{subformula} \\
+% "\underleftwitchonpitchfork "\marg{subformula}
+% \end{flushleft}
+% instead of the above.
+%
+% \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 Halloween, 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, \eg "\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{Bats}
+%
+% For some people, bats are even more horrifying than ghosts. The
+% \packlass{\halloweenmath} package provides a collection of commands for
+% drawing bat-like symbols that are closely analogous to the ghost-related
+% ones.
+%
+% \DescribeMacro{\mathbat}
+% \DescribeMacro{\mathrightbat}
+% \DescribeMacro{\mathleftbat}
+% You can get an ordinary symbol resembling a bat flying, respectively,
+% toward you, toward the right, and toward the left with the three
+% argumentless commands "\mathbat", "\mathrightbat", and "\mathleftbat". The
+% height of these symbols has intentionally been made pretty small, to
+% facilitate their use in superscripts.
+%
+% \DescribeMacro{\xrightflutteringbat}
+% \DescribeMacro{\xleftflutteringbat}
+% You can get extensible ``arrow-like'' relation symbols that depict a
+% fluttering bat by means of the following constructs:
+% \begin{flushleft}
+% "\xrightflutteringbat"\oarg{under text}\marg{over text} \\
+% "\xleftflutteringbat "\oarg{under text}\marg{over text}
+% \end{flushleft}
+% \DescribeMacro{\overrightflutteringbat}
+% \DescribeMacro{\overleftflutteringbat}
+% \DescribeMacro{\underrightflutteringbat}
+% \DescribeMacro{\underleftflutteringbat}
+% And these are the associated ``over\mbox{-}\slash under-arrow-like''
+% commands:
+% \begin{flushleft}
+% "\overrightflutteringbat "\marg{subformula} \\
+% "\overleftflutteringbat "\marg{subformula} \\
+% "\underrightflutteringbat"\marg{subformula} \\
+% "\underleftflutteringbat "\marg{subformula}
+% \end{flushleft}
+%
+% \DescribeMacro{\overbat}
+% \DescribeMacro{\underbat}
+% There are, finally, two more commands that have no parallel in the
+% collection of ghostly symbols (because ghost are to tall!): they are
+% \begin{flushleft}
+% "\overbat "$*$\marg{subformula} \\
+% "\underbat"$*$\marg{subformula}
+% \end{flushleft}
+% where $*$ indicates an optional "*" denoting, as usual, their
+% \mbox{$*$-form}. These constructs typeset \meta{subformula} respectively
+% surmounted by the bat produced by "\mathbat", or with that symbol
+% underneath. The normal (\emph{i.e.}, unstarred) form pretends that the bat
+% has zero width (but some height), so that, say, "$x+\overbat{y}+z$" has the
+% same horizontal spacing as "$x+y+z$"; if you prefer that the actual width
+% of the bat be taken into account instead, then use the starred variants.
+%
+% \subsubsection{Skulls}
+%
+% \DescribeMacro{\skull}
+% \DescribeMacro{\bigskull}
+% For skulls, I~imagined a r\^{o}le very similar to that of
+% \hyperref[ssS:Pumpkins]{pumpkins}. Indeed, anything that is shaped like a
+% human head reminds me of symbols like "\oplus"~($\oplus$) and
+% "\otimes"~($\otimes$), so that my fantasy immediately goes to a binary
+% operator and its associated ``large'' operator. In this case, we have:
+% \begin{itemize}
+% \item
+% "\skull", which is the binary operator (similar to "\oplus");
+% \item
+% "\bigskull", which is the ``large'' operator (similar to "\bigoplus") and
+% which, like all symbols of this kind, becomes significantly larger in
+% displayed math.
+% \end{itemize}
+% As for all ``large'' operators defined by this package, the
+% [\opt{no}]\opt{sumlimits} options from the \packlass{\amsmath} package
+% affect the "\bigskull" command too.
+%
+% \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{More \textquotedblleft arrow-like\textquotedblright\ symbols
+% (these don\textquoteright t scare!)}
+%
+% If designing the first symbol, the "\mathwitch", could be relatively
+% entertaining, the implementation of the other operators and ordinary
+% symbols like "\pumpkin", "\mathghost", "\mathcloud", or "\bigskull" soon
+% became a rather dull and repetitive task, that essentialy consisted of
+% nothing more than placing lots of dots on a grid. The part related to the
+% extensible ``arrow-like'' commands was a bit more amusing, since it
+% involved dealing with at least a few typical \TeX nical aspects. Probably,
+% it was for this reason that this field grew so much in passing from the
+% first release of the package to the second.
+%
+% \subsubsection{Script-style version of standard over\protect\slash under
+% arrows}
+% \label{ssS:StandardArrows}
+%
+% 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}
+%
+% \subsubsection{\textquotedblleft Unwitched\textquotedblright\ brooms
+% and pitchforks}
+%
+% In the last years, the use of unmanned aircrafts has become increasingly
+% important, and it has in parallel become more and more common to see flying
+% devices of this kind even across the skies of our cities (just think of
+% drones and of how they tend to be employed ubiquitously for the most
+% heterogeneous kinds of jobs and services). Needless to say, it was
+% inevitable that this aeronautical revolution propagated even to an
+% inherently conservative world like that of sorcery, and it should come as
+% no great surprise to learn that the \packlass{\halloweenmath} package now
+% features ``unwitched'' versions of all the ``arrow-like'' extensible
+% symbols too, both of those that depict brooms and of those which stick to
+% the original pitchfork-like shape. The useful side of these is that the
+% absence of the witch allows for a reduction of the vertical space they take
+% up.
+%
+% \DescribeMacro{\xrightbroom}
+% \DescribeMacro{\xleftbroom}
+% To begin with, we have the extensible ``arrow-like'' relations, those
+% modeled after "\xrightarrow": they are
+% \begin{flushleft}
+% "\xrightbroom"\oarg{under text}\marg{over text} \\
+% "\xleftbroom "\oarg{under text}\marg{over text} \\
+% \end{flushleft}
+% and produce extensible brooms \emph{without} a witch sitting on them.
+% \DescribeMacro{\xrightpitchfork}
+% \DescribeMacro{\xleftpitchfork}
+% The commands
+% \begin{flushleft}
+% "\xrightpitchfork"\oarg{under text}\marg{over text} \\
+% "\xleftpitchfork "\oarg{under text}\marg{over text}
+% \end{flushleft}
+% are almost identical, only they yield pitchforks instead of brooms---or, if
+% you prefer, brooms with the shape that was used in version~0.01 of this
+% package.
+%
+% \DescribeMacro{\rightbroom}
+% \DescribeMacro{\leftbroom}
+% When both the \meta{under text} and the \meta{over text} are void, the
+% "\xrightbroom"\,\ldots\linebreak[0]"\xleftpitchfork" commands yield a
+% symbol that is, on purpose, more or less as large as what "\xrightarrow{}"
+% yields (\emph{i.e.},~$\xrightarrow{}$); but it turns out that such a short
+% broom (or pitchfork) completely lacks the broomstick. For this reason, the
+% two (argumentless) commands "\rightbroom" and "\leftbroom" has been
+% provided too: they typeset a broom the same length of a
+% "\longrightarrow"\slash "\longleftarrow" ($\longrightarrow$\slash
+% $\longleftarrow$).
+% \DescribeMacro{\hmrightpitchfork}
+% \DescribeMacro{\hmleftpitchfork}
+% It would now seem logical to infer that the two companion commands that
+% typeset pitchforks should be named "\rightpitchfork" and "\leftpitchfork";
+% unfortunately, these names already denote two different (albeit vaguely
+% similar) symbols supplied by the \packlass{MnSymbol} package. Because of
+% this potential name clash, we have chosen instead to call them
+% "\hmrightpitchfork" and "\hmleftpitchfork", respectively (the
+% \texttt{hm}~prefix, of course, stands for ``Halloween math'').
+%
+% Before getting to the group of the ``over\mbox{-}\slash under-arrow-like''
+% extensible brooms, a preliminary statement needs to be made. For the
+% ``witched'' version of all these, we had chosen to typeset them in the
+% relative script style associated to the style of the affected subformula.
+% For example, in a construct like
+% \begin{verbatim}$W_{\overrightwitchonbroom{x_{1}+\dots+x_{n}}}$\end{verbatim}
+% the subformula "x_{1}+\dots+x_{n}", argument of the
+% "\overrightwitchonbroom" command, is set in script style, therefore the
+% style applied to the covering broom (and witch) will be the scriptscript
+% style. We already remarked in Subsection~\ref{ssS:StandardArrows} that
+% this is not what the standard ``over\mbox{-}\slash under-arrow'' commands
+% do: instead, they use for the arrow the same style as that in which the
+% argument gets typeset. The reason for this different behavior was that,
+% with the same style of the affected subformula, the witch would have looked
+% too large; but when the witch isn't there, both solutions are viable, and
+% we do provide both.
+%
+% ^^A \paragraph{Brooms\slash pitchforks in the same relative style.}
+% We have, in the first place, a set of commands for placing brooms or
+% pitchforks (a.k.a.\ version-0.01-styled brooms) over or under a subformula,
+% setting them in the same style as the subformula itself.
+% \DescribeMacro{\overrightbroom}
+% \DescribeMacro{\overleftbroom}
+% \DescribeMacro{\underrightbroom}
+% \DescribeMacro{\underleftbroom}
+% There are four ``over\mbox{-}\slash under-arrow-like'' extensible
+% brooms\ldots
+% \begin{flushleft}
+% "\overrightbroom "\marg{subformula} \\
+% "\overleftbroom "\marg{subformula} \\
+% "\underrightbroom"\marg{subformula} \\
+% "\underleftbroom "\marg{subformula}
+% \end{flushleft}
+% \DescribeMacro{\overrightpitchfork}
+% \DescribeMacro{\overleftpitchfork}
+% \DescribeMacro{\underrightpitchfork}
+% \DescribeMacro{\underleftpitchfork}
+% \ldots and four corresponding ``over\mbox{-}\slash under-arrow-like''
+% extensible pitchforks:
+% \begin{flushleft}
+% "\overrightpitchfork "\marg{subformula} \\
+% "\overleftpitchfork "\marg{subformula} \\
+% "\underrightpitchfork"\marg{subformula} \\
+% "\underleftpitchfork "\marg{subformula}
+% \end{flushleft}
+%
+% ^^A \paragraph{Brooms\slash pitchforks in relative script style.}
+% Then, for each of the commands just listed, a corresponding variant is
+% provided that sets the broom, or the pitchfork, in the relative script
+% style of the style applied to \meta{subformula}, and which is named
+% following the same convention we already used for the commands of
+% Subsection~\ref{ssS:StandardArrows}, that is, inserting the "script"
+% substring.
+% \DescribeMacro{\overscriptrightbroom}
+% \DescribeMacro{\overscriptleftbroom}
+% \DescribeMacro{\underscriptrightbroom}
+% \DescribeMacro{\underscriptleftbroom}
+% Thus, again, we find four ``over\mbox{-}\slash under-arrow-like''
+% extensible brooms\ldots
+% \begin{flushleft}
+% "\overscriptrightbroom "\marg{subformula} \\
+% "\overscriptleftbroom "\marg{subformula} \\
+% "\underscriptrightbroom"\marg{subformula} \\
+% "\underscriptleftbroom "\marg{subformula}
+% \end{flushleft}
+% \DescribeMacro{\overscriptrightpitchfork}
+% \DescribeMacro{\overscriptleftpitchfork}
+% \DescribeMacro{\underscriptrightpitchfork}
+% \DescribeMacro{\underscriptleftpitchfork}
+% \ldots and four matching ``over\mbox{-}\slash under-arrow-like'' extensible
+% pitchforks:
+% \begin{flushleft}
+% "\overscriptrightpitchfork "\marg{subformula} \\
+% "\overscriptleftpitchfork "\marg{subformula} \\
+% "\underscriptrightpitchfork"\marg{subformula} \\
+% "\underscriptleftpitchfork "\marg{subformula}
+% \end{flushleft}
+%
+% \paragraph*{Please note:}
+% Since all of the commands listed in this subsection omit the witch, none
+% of them has got a \mbox{$*$-form} for adding a cat (the cat can only go
+% with the witch: no witch, no cat).
+%
+% \subsubsection{Summary of the naming scheme}
+%
+% It is worth noting that the commands for the extensible brooms\slash
+% pitchforks follow a consistent naming scheme: the name is of the form
+% \begin{center}
+% \texttt{\bslash}\meta{x-over-under}\meta{opt-script}^^A
+% \meta{left-right}\meta{opt-witch}\meta{broom-pitchf}
+% \end{center}
+% where
+% \begin{flalign*}
+% \meta{x-over-under} &\longrightarrow
+% \texttt{x}\binvert\texttt{over}\binvert\texttt{under} &
+% \meta{opt-script} &\longrightarrow
+% \meta{empty}\binvert\texttt{script} \\
+% \meta{left-right} &\longrightarrow
+% \texttt{left}\binvert\texttt{right} &
+% \meta{opt-witch} &\longrightarrow
+% \meta{empty}\binvert\texttt{witchon} \\
+% \meta{broom-pitchf} &\longrightarrow
+% \texttt{broom}\binvert\texttt{pitchfork}
+% \end{flalign*}
+% with the constraint that \meta{opt-script} must be \meta{empty} if either \( \meta{x-over-under} =
+% \texttt{x} \) or \( \meta{opt-witch} \neq \meta{empty} \).
+%
+% \section
+% [Installing the pacakge code and documentation]
+% {Installing the package code and documentation\footnote{^^A
+% Recall that you need to read this section only in the unusual case that you
+% have to carry out a manual installation from the sources; normally, you'll
+% be using a prepackaged \TeX\ distribution like
+% \href{https://www.tug.org/texlive/}{\TeX~Live} or
+% \href{https://miktex.org/}{MiK\TeX}, which can automatically manage
+% installation as well as updates.^^A
+% }}
+%
+% 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 personal packages.
+% The accepted TDS-compliant directory where the above file should be put is
+% \begin{quote}
+% \filedir{\$TEXMF/tex/latex/halloweenmath/}
+% \end{quote}
+%
+% Please note: 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 it.
+%
+% \subsection{Documentation}
+%
+% To produce this documentation, run \LaTeX\ three times (for the ToC to get
+% right) on the file \filedir{\halloweenmath.dtx}. This won't give you the
+% index and the change history, though: for those, you should run
+% \emph{MakeIndex} on the files \filedir{\halloweenmath.idx} and
+% \filedir{\halloweenmath.glo}, obtained during the last of the aforesaid
+% three \LaTeX\ runs, with styles \filedir{gind.ist} and \filedir{gglo.ist},
+% respectively (which 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{The makefile}
+% \label{sS:Makefile}
+%
+% A (quite trivial!\@) makefile, named \filedir{Makefile}, that ``knows'' how
+% to carry out the installation, is offered along with the package. Although
+% it is not a required part of the distribution (as per LPPL\@), you may find
+% that some distributors supply it all the same (I~hope the CTAN\@ sites will
+% do so). With this makefile in the same directory as the two source files
+% \filedir{\filename} and \filedir{\halloweenmath.ins}, the simple shell
+% command, given inside that same directory,
+% \begin{quote}
+% \ttfamily
+% make
+% \end{quote}
+% will \emph{both} extract the code file \emph{and} typeset the full
+% documentation (in~PDF\@). Type
+% \begin{quote}
+% \ttfamily
+% make help
+% \end{quote}
+% for more information.
+%
+% \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{https://tex.stackexchange.com/q/336768/69818}
+%
+% \bibitem{bib:manual}
+% \emph{User's manual for the \packlass{\halloweenmath} package}, included
+% in the documentation of the \packlass{\halloweenmath} package,\\
+% \href{file:halloweenmath-man.pdf}
+% {\nolinkurl{$TEXMF/doc/latex/halloweenmath/halloweenmath-man.pdf}}
+%
+% \IfImplementation{
+% \bibitem{bib:diffs-m}
+% File \filedir{diffs-m.txt}, which is part of the standard
+% \hologo{AmSLaTeX} distribution,\\
+% \nolinkurl{$TEXMF/doc/latex/amsmath/diffs-m.txt}
+%
+% \bibitem{bib:std}
+% \emph{Why does the \packlass{\amsmath} package define
+% \textnormal{\cs{std@minus}} and \textnormal{\cs{std@equal}}?},\\
+% \url{https://tex.stackexchange.com/q/352043}
+% }{}
+%
+% \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{amsmath,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}
+ [2017/04/25 v0.10a (development)]
+% \end{macrocode}
+%
+% \subsection{Initial code}
+%
+% \begin{macro}{\@HwM@say@BOO}
+% Of course, to make this anything even vaguely resembling an ``Easter egg'',
+% I~should at least pretend to try to obfuscate the code; but too much time
+% has already been wasted on this huge and ridicolous heap of foolishness.
+% \begin{macrocode}
+\newcommand*\@HwM@say@BOO{%
+ \begingroup
+ \escapechar \m@ne
+ \def~{\string\\}%
+ \def\-{\space\space}%
+ \def\+{\space\space\space\space}%
+ \def\={\+\+\+\+}%
+ \def\*{****}%
+ \typeout{}%
+ \typeout{\+ _-==-_ \+ /~/~/~}%
+ \typeout{\+|\-\-\-|\+< BOO! >\+\+\+\today...}%
+ \typeout{\+|(.)(.)|\+/~/~/~/}%
+ \typeout{\++--/~--+\- /\=\*\*\*\*\*\*\*}%
+ \typeout{\+ [::::] __/ \= ... This is HALLOWEENMATH!}%
+ \typeout{\+\-----\-\+\=\*\*\*\*\*\*\*}%
+ \typeout{}%
+ \endgroup
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@opt@say@BOO}
+% Well, at least do not add comments to what is already crystal clear by
+% itself\ldots
+% \begin{macrocode}
+\newcommand*\@HwM@opt@say@BOO{}
+% \end{macrocode}
+% \end{macro}
+%
+% \subsection{Declaration of options}
+%
+% Hidden options. Note that they are later processed in the order in which
+% they are declared here.
+% \begin{macrocode}
+\DeclareOption{silent}{%
+ \let \@HwM@opt@say@BOO \@empty
+}
+\DeclareOption{boo}{%
+ \let \@HwM@opt@say@BOO \@HwM@say@BOO
+}
+\DeclareOption{boo-10-31}{%
+ \ifnum\month=10
+ \ifnum\day=31
+ \let \@HwM@opt@say@BOO \@HwM@say@BOO
+ \else
+ \let \@HwM@opt@say@BOO \@empty
+ \fi
+ \else
+ \let \@HwM@opt@say@BOO \@empty
+ \fi
+}
+% \end{macrocode}
+%
+% \subsection{Option processing}
+%
+% Note that, at the end, at least we release the memory taken up by this
+% piece of buffoonery.
+% \begin{macrocode}
+\ExecuteOptions{boo-10-31}
+\ProcessOptions\relax
+\@HwM@opt@say@BOO
+\let \@HwM@say@BOO = \@undefined
+\let \@HwM@opt@say@BOO = \@undefined
+% \end{macrocode}
+%
+% \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 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 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
+% bounding box height, in coordinate units;\\
+% \param
+% $y$-coordinate of lower left corner of bounding box;\\
+% \param
+% additional code to be executed during initialization;\\
+% \param
+% font selector (\eg "\textfont");\\
+% \param
+% bounding box width, in coordinate units;\\
+% \param
+% $x$-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}
+% \changes{0.10}{2017 Apr 16}{Corrected bug: the size of the strut used to
+% be that of \cs{bigoplus}}
+% Vertical phantom the size of "\oplus". Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@oplus@strut[1]{%
+ \@HwM@short@circuited@vphant #1\oplus
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@bigoplus@strut}
+% \changes{0.10}{2017 Apr 16}{Added this macro}
+% Vertical phantom the size of "\bigoplus". Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\displaystyle").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@bigoplus@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@bigop@picture}
+% \begin{macro}{\end@HwM@bigop@picture}
+% This is actually a definition of an environment. The environment beign
+% defined, namely \env{@HwM@bigop@picture}, is simply syntactic sugar for a
+% typical invocation of the \env{@HwM@math@picture} environment, for a
+% picture having the vertical size of a "\bigoplus", 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, immediately
+% after the single argument to this environment, which is
+% \begin{paramlist}
+% \param
+% style selector (\eg "\displaystyle").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@bigop@picture[1]{%
+ \@HwM@math@picture{0}{-1}{\@HwM@bigoplus@strut #1}%
+}
+\let\end@HwM@bigop@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, immediately
+% after the single argument to this environment, which is
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle").
+% \end{paramlist}
+% \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}
+%
+% \paragraph*{Comment added in version~0.10:}
+% After all, I~think I'd better recap what the full argument lists for the
+% ``specialized'' math picture environments are.
+%
+% \medskip
+% Full argument list for \env{@HwM@large@picture}:
+% \begin{paramlist}
+% \param
+% bounding box width, in coordinate units;\\
+% \param
+% $x$-coordinate of lower left corner of bounding box.
+% \end{paramlist}
+%
+% \medskip
+% Full argument list for \env{@HwM@small@picture}:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont");\\
+% \param
+% bounding box width, in coordinate units;\\
+% \param
+% $x$-coordinate of lower left corner of bounding box.
+% \end{paramlist}
+%
+% \medskip
+% Full argument list for both \env{@HwM@bigop@picture} and
+% \env{@HwM@oplus@picture}:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont");\\
+% \param
+% bounding box width, in coordinate units;\\
+% \param
+% $x$-coordinate of lower left corner of bounding box.
+% \end{paramlist}
+%
+% \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}
+%
+% \begin{macro}{\@HwM@bold@version@name}
+% In version~0.01 of this package, the definition of the "\@HwM@if@bold@math"
+% macro (see below) used to be
+% \begin{verbatim}\newcommand*\@HwM@if@bold@math{%
+% \def\@tempa{bold}%
+% \ifx\math@version\@tempa
+% \expandafter\@firstoftwo
+% \else
+% \expandafter\@secondoftwo
+% \fi
+%}\end{verbatim}
+% We have now decided to set the comparison string (\texttt{bold}) here, once
+% and for all: this allows the following macro to be purely expandable, a
+% feature we'll now need.
+% \begin{macrocode}
+\newcommand*\@HwM@bold@version@name{bold}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@if@bold@math}
+% \changes{0.10}{2017 Apr 16}{Made purely expandable}
+% \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. Now made purely expandable (see above).
+% \begin{macrocode}
+\newcommand*\@HwM@if@bold@math{%
+ \ifx\math@version\@HwM@bold@version@name
+ \expandafter\@firstoftwo
+ \else
+ \expandafter\@secondoftwo
+ \fi
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@choose@thicknesses}
+% Shuffles arguments according to the current math version. Now purely
+% expandable.
+% \begin{macrocode}
+\newcommand*\@HwM@choose@thicknesses[3]{%
+ \@HwM@if@bold@math{#1#3}{#1#2}
+}
+% \end{macrocode}
+% The typical use of this macro is as follows: suppose you have a macro
+% \cmd{\CS} with, say, five arguments, and suppose you want to invoke it
+% passing different values for some of the arguments, depending on the
+% current math version; more precisely, let's say that you want the following
+% call to be made
+% \begin{flushleft}
+% \small
+% "\CS{"\meta{fixed-value1}"}{"\meta{fixed-value2}"}{"^^A
+% \meta{bold-value3}"}{"\meta{bold-value4}"}{"^^A
+% \meta{bold-value5}"}"
+% \end{flushleft}
+% if the current math version is \texttt{bold}, but that you want, instead,
+% to call
+% \begin{flushleft}
+% \small
+% "\CS{"\meta{fixed-value1}"}{"\meta{fixed-value2}"}{"^^A
+% \meta{nrml-value3}"}{"\meta{nrml-value4}"}{"^^A
+% \meta{nrml-value5}"}"
+% \end{flushleft}
+% if it is not; then you would say
+% \begin{flushleft}
+% \small
+% "\@HwM@choose@thicknesses{\CS{"\meta{fixed-value1}"}{"^^A
+% \meta{fixed-value2}"}}"\\
+% " {{"\meta{normal-value3}"}{"\meta{normal-value4}"}{"^^A
+% \meta{normal-value5}"}}"\\
+% " {{"\meta{bold-value3}"}{"\meta{bold-value4}"}{"^^A
+% \meta{bold-value5}"}}"
+% \end{flushleft}
+% Note the inner pairs of braces; as usual, they can be omitted if they
+% surround a single token, \eg
+% \begin{verbatim}\@HwM@choose@thicknesses{\CS{FFF1}\textfont}
+% {\thr@@{4.0}{5.0}}
+% {{BBB3}{BBB4}\@empty}\end{verbatim}
+% \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 version. 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 version 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
+% "l"~for a right-facing witch, "r"~for a left-facing one;\\
+% \param
+% "r"~for a right-facing witch, "l"~for a left-facing one;\\
+% \param
+% main drawing thickn., in units of the default-rule-thickness
+% "\fontdimen";\\
+% \param
+% thickness of the broomstick and of the cat's tail, in the same units;\\
+% \param
+% thickness of hair (beard, whiskers), in points~(\texttt{pt}).
+% \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
+% "l"~for a right-facing witch, "r"~for a left-facing one;\\
+% \param
+% "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
+% font selector (\eg "\textfont");\\
+% \param
+% 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
+% font selector (\eg "\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}
+% Draws the part of the cat that is shared also by the extensible brooms;
+% ``private'' variant, parameters are as follows:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont");\\
+% \param
+% 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
+% font selector (\eg "\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
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont").
+% \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}
+%
+% \begin{macro}{\@HwM@Small@Witch@Wo@Broom}
+% Draws the small witch w/o the broom. This one exists only in the
+% ``public'' variant, with the following argument:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\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}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Small@Cat@On@Hori@Broom}
+% Draws a small cat on a horizontal broomstick. This one exists only in the
+% ``public'' variant, with the following argument:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\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}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Drawing the pumpkins}
+%
+% Here we group the macros that take care of drawing the pumpkins.
+% Figure~\ref{fig:pumpkins} shows a sketch of the relevant drawings.
+%
+% \begin{figure}[tp]
+% \newcommand*{\PumpkinSmallMouth}[7]{^^A
+% \polygon*^^A
+% (-#1)(-#2)(-#3)(0,#4)(#3)(#2)(#1)^^A
+% (#5)(#6)(0,#7)(-#6)(-#5)^^A
+% }
+% \newcommand*{\PumpkinLargeMouth}[9]{^^A
+% \polygon*^^A
+% (-#1)(-#2)(-#3)(-#4)(0,#5)(#4)(#3)(#2)(#1)^^A
+% (#6)(#7)(#8)(0,#9)(-#8)(-#7)(-#6)^^A
+% }
+%
+% \centering
+%
+% The binary operator variant:\\*[\medskipamount]
+% \begin{picture}(3.2,4)(-1.6,-2)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-2,-2)(1,0){5}{\line(0,1){4}}
+% \multiput(-2,-2)(0,1){5}{\line(1,0){4}}
+% \color{black}
+% \roundcap
+% \linethickness{1.3pt}
+% \Line(-.1,1)(-.15,1.4)(.15,1.4)(.1,1)
+% \Line(-.1,-1)(.1,-1)
+% \newcommand*{\PumpkinProfile}[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}}%
+% }
+% \PumpkinProfile-
+% \PumpkinProfile+
+% \PumpkinSmallMouth{1,-.1}{.7,-.5}{.4,-.4}
+% {-.7}
+% {.6,-.3}{.3,-.2}
+% {-.4}
+% \end{picture}
+%
+% \bigskip\bigskip
+%
+% The small variant:\\*[\medskipamount]
+% \begin{picture}(4.5,4)(-2.25,-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}
+% \roundcap
+% \linethickness{2pt}
+% \Line(-.1,1.5)(-.15,2)(.15,2)(.1,1.5)
+% \Line(-.1,-1.8)(.1,-1.8)
+% \newcommand*{\PumpkinProfile}[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}}%
+% }
+% \PumpkinProfile-
+% \PumpkinProfile+
+% \polygon*(0,.2)(-.2,-.2)(.2,-.2)
+% \PumpkinSmallMouth{1.3,-.3}{.8,-.8}{.5,-.7}
+% {-1}
+% {.7,-.6}{.4,-.5}
+% {-.7}
+% \end{picture}
+%
+% \bigskip\bigskip
+%
+% The large variant:\\*[\medskipamount]
+% \begin{picture}(9,8)(-4.5,-4)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-5,-4)(1,0){11}{\line(0,1) {8}}
+% \multiput(-5,-4)(0,1) {9}{\line(1,0){10}}
+% \color{black}
+% \roundcap
+% \linethickness{3pt}
+% \Line(-.15,2.25)(-.3,3)(.3,3)(.15,2.25)
+% \Line(-.15,-2.7)(.15,-2.7)
+% \newcommand*{\PumpkinProfile}[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}}%
+% }
+% \PumpkinProfile-
+% \PumpkinProfile+
+% \polygon*(0,.35)(-.35,-.35)(.35,-.35)
+% \PumpkinLargeMouth{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{picture}
+%
+% \caption{Sketches of the pumpkins}
+% \label{fig:pumpkins}
+% \end{figure}
+%
+% As you can see in figure~\ref{fig:pumpkins}, pumpkins come in three
+% variants: a binary operator and the two versions (both for display and
+% nondisplay math) of a ``large'' operator. Below, the macros for each
+% version are preceded by one or two useful ``subroutines'', that draw some
+% patterns that appear more than once in the picture.
+%
+% \begin{macro}{\@HwM@large@pumpkin@profile}
+% Subroutine that draws the outline of the pumpkin and one eye, for a
+% ``large'' operator in display style. Argument~\#1 is either \texttt{-}
+% or~\texttt{+}, depending on which half of the pumpkin you want to draw.
+% \begin{macrocode}
+\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}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@large@pumpkin@mouth}
+% This subroutine draws the variant of the mouth that is used by the display
+% version of the ``large'' operator. The parameters are suitable point
+% coordinates.
+% \begin{macrocode}
+\newcommand*\@HwM@large@pumpkin@mouth[9]{%
+ \polygon*%
+% \end{macrocode}
+% Lower lip:
+% \begin{macrocode}
+ (-#1)(-#2)(-#3)(-#4)(0,#5)(#4)(#3)(#2)(#1)%
+% \end{macrocode}
+% Upper lip:
+% \begin{macrocode}
+ (#6)(#7)(#8)(0,#9)(-#8)(-#7)(-#6)%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@large@pumpkin}
+% Private version of the macro that draws the pumpkin correspondng to a
+% ``large'' operator used in display math mode. Argument:
+% \begin{paramlist}
+% \param
+% drawing thickness, in units of the default-rule-thickness "\fontdimen".
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@large@pumpkin[1]{%
+ \begin{@HwM@bigop@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@bigop@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Large@Pumpkin}
+% Public version of the above; requires no parameters.
+% \begin{macrocode}
+\newcommand*\@HwM@Large@Pumpkin{%
+ \@HwM@choose@thicknesses \@HwM@large@pumpkin
+ {{1.8}}%
+ {{2.2}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@pumpkin@profile}
+% Subroutine that draws the outline of the pumpkin and one eye, for a
+% ``large'' operator \emph{not} in display style. Argument~\#1 is either
+% \texttt{-} or~\texttt{+}, depending on which half of the pumpkin you want
+% to draw.
+% \begin{macrocode}
+\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}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@pumpkin@mouth}
+% This subroutine draws the variant of the mouth that is shared between the
+% binary operator and the nondisplay version of the ``large'' operator. The
+% parameters are suitable point coordinates.
+% \begin{macrocode}
+\newcommand*\@HwM@small@pumpkin@mouth[7]{%
+ \polygon*%
+% \end{macrocode}
+% Lower lip:
+% \begin{macrocode}
+ (-#1)(-#2)(-#3)(0,#4)(#3)(#2)(#1)%
+% \end{macrocode}
+% Upper lip:
+% \begin{macrocode}
+ (#5)(#6)(0,#7)(-#6)(-#5)%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@pumpkin}
+% Private version of the macro that draws the pumpkin correspondng to a
+% ``large'' operator used in nondisplay math mode. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont");\\
+% \param
+% drawing thickness, in units of the default-rule-thickness "\fontdimen".
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@small@pumpkin[3]{%
+ \begin{@HwM@bigop@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@bigop@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Small@Pumpkin}
+% Public version of the above, with the following arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@Small@Pumpkin[2]{%
+ \@HwM@choose@thicknesses{\@HwM@small@pumpkin #1#2}%
+ {{}}%
+ {{1.5}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@binop@pumpkin@profile}
+% Subroutine that draws the outline of the pumpkin and one eye, for a binary
+% operator (in whatever style). Argument~\#1 is either \texttt{-}
+% or~\texttt{+}, depending on which half of the pumpkin you want to draw.
+% \begin{macrocode}
+\newcommand*\@HwM@binop@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}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@binop@pumpkin}
+% Private version of the macro that draws the pumpkin correspondng to a
+% binary operator. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% font selector (\eg "\textfont");\\
+% \param
+% drawing thickness, in units of the default-rule-thickness "\fontdimen".
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@binop@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@binop@pumpkin@profile-%
+ \@HwM@binop@pumpkin@profile+%
+ \@HwM@small@pumpkin@mouth{1,-.1}{.7,-.5}{.4,-.4}%
+ {-.7}%
+ {.6,-.3}{.3,-.2}%
+ {-.4}%
+ \end{@HwM@oplus@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Binop@Pumpkin}
+% Public version of the above, with the following arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@Binop@Pumpkin[2]{%
+ \@HwM@choose@thicknesses{\@HwM@binop@pumpkin #1#2}%
+ {{.6}}%
+ {{1.2}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Drawing the skulls}
+%
+% Now it's the turn of the macros that take care of drawing the skulls.
+% Figure~\ref{fig:skulls} shows a sketch of the relevant drawings.
+%
+% \begin{figure}[tp]
+% \newcommand*{\binaryskullnose}[8]{^^A
+% \moveto(0,-.#1)^^A
+% \curveto(-.#2,-.#1)(-.#3,-.#4)(-.#5,-.#6)^^A
+% \curveto(-.#7,-.#8)(.#7,-.#8)(.#5,-.#6)^^A
+% \curveto(.#3,-.#4)(.#2,-.#1)(0,-.#1)^^A
+% \fillpath
+% }
+% \newcommand*{\semibinaryskullcontour}[1]{^^A
+% \moveto(#1.15,0)^^A
+% \curveto(#1.15,.1)(#1.15,.21)(#1.4,.2)^^A
+% \curveto(#1.6,.19)(#1.69,.1)(#1.7,0)^^A
+% \curveto(#1.71,-.1)(#1.6,-.3)(#1.5,-.3)^^A
+% \curveto(#1.4,-.3)(#1.15,-.2)(#1.15,0)^^A
+% \fillpath
+% \cbezier(0,1.333336)(#11,1.333336)(#11.2,0.5)(#11,0)^^A
+% \cbezier(#11,0)(#11.05,-.9)(#1.5,-.3)(#1.5,-.65)^^A
+% }
+% \newcommand*{\semibinaryskullteeth}[2]{^^A
+% \moveto(#1.5,-.7)^^A
+% \curveto(#1.45,-.6)(#1.4,-.6)(#1.35,-.7)^^A
+% \curveto(#1.4,-1.2)(#1.5,-1.2)(#1.5,-.7)^^A
+% \strokepath
+% \moveto(#1.33,-.7)^^A
+% \curveto(#1.3,-.6)(#1.22,-.6)(#1.19,-.75)^^A
+% \curveto(#1.15,-.9)(#1.38,-.9)(#1.33,-.7)^^A
+% \strokepath
+% \moveto(#1.17,-.75)^^A
+% \curveto(#1.13,-.65)(#1.05,-.62)(#1.02,-.75)^^A
+% \curveto(#2.03,-.95)(#1.22,-.95)(#1.17,-.75)^^A
+% \strokepath
+% }
+%
+% \newcommand*{\semismallskullcontour}[1]{^^A
+% \moveto(#1.225,0)^^A
+% \curveto(#1.225,.15)(#1.225,.315)(#1.6,.3)^^A
+% \curveto(#1.9,.285)(#11.035,.15)(#11.05,0)^^A
+% \curveto(#11.065,-.15)(#1.9,-.45)(#1.75,-.45)^^A
+% \curveto(#1.6,-.45)(#1.225,-.3)(#1.225,0)^^A
+% \fillpath
+% \cbezier(0,2)(#11.5,2)(#11.8,0.75)(#11.5,0)^^A
+% \cbezier(#11.5,0)(#11.575,-1.35)(#1.75,-.45)(#1.75,-1)^^A
+% }
+% \newcommand*{\semismallskulljaw}[1]{^^A
+% \moveto(#11.25,-.9)^^A
+% \curveto(#11.24,-1.2)(#11.2,-1)(#11.1,-1.3)^^A
+% \curveto(#11,-1.6)(#11,-1.8)(#1.75,-1.9)^^A
+% \curveto(0,-2.1)(#1.3,-2)(0,-2)^^A
+% \strokepath
+% }
+% \newcommand*{\semismallskullinnerjaw}[1]{^^A
+% \moveto(#11,-.9)^^A
+% \curveto(#1.9,-1)(#11,-1.5)(#1.75,-1.5)^^A
+% \strokepath
+% }
+% \newcommand*{\semismallskullteeth}[2]{^^A
+% \moveto(#1.75,-1)^^A
+% \curveto(#1.65,-.9)(#1.6,-.9)(#1.5,-1)^^A
+% \curveto(#1.6,-2)(#1.7,-2)(#1.75,-1)^^A
+% \strokepath
+% \moveto(#1.45,-1)^^A
+% \curveto(#1.4,-.9)(#1.3,-.9)(#1.285,-1.05)^^A
+% \curveto(#1.2,-1.35)(#1.6,-1.35)(#1.45,-1)^^A
+% \strokepath
+% \moveto(#1.25,-1.05)^^A
+% \curveto(#1.2,-.9)(#1.04,-.9)(#1.03,-1.05)^^A
+% \curveto(#2.08,-1.4)(#1.35,-1.4)(#1.25,-1.05)^^A
+% \strokepath
+% \moveto(#1.5,-1.5)^^A
+% \curveto(#1.47,-1.65)(#1.35,-1.6)(#1.3,-1.55)^^A
+% \curveto(#1.15,-1.25)(#1.65,-1.25)(#1.5,-1.5)^^A
+% \strokepath
+% \moveto(#1.25,-1.55)^^A
+% \curveto(#1.2,-1.7)(#1.04,-1.7)(#1.03,-1.55)^^A
+% \curveto(#2.1,-1.3)(#1.35,-1.3)(#1.25,-1.55)^^A
+% \strokepath
+% }
+%
+% \newcommand*{\largeskullnose}[9]{^^A
+% \moveto(0,-#1)^^A
+% \curveto(-#2,-#1)(-#3,-#1)(-#4,-#5)^^A
+% \curveto(-#6,-#7)(-#8,-#9)(0,-#9)^^A
+% \curveto(#8,-#9)(#6,-#7)(#4,-#5)^^A
+% \curveto(#3,-#1)(#2,-#1)(0,-#1)^^A
+% \fillpath
+% }
+% \newcommand*{\semilargeskullcontour}[1]{^^A
+% \moveto(#1.3375,0)^^A
+% \curveto(#1.3375,.225)(#1.3375,.4725)(#1.9,.45)^^A
+% \curveto(#11.35,.4275)(#11.5525,.225)(#11.575,0)^^A
+% \curveto(#11.5975,-.225)(#11.35,-.675)(#11.125,-.675)^^A
+% \curveto(#1.9,-.675)(#1.3375,-.45)(#1.3375,0)^^A
+% \fillpath
+% \cbezier(#12,2)(#12.1,1.8)(#12.7,1.125)(#12.25,0)^^A
+% \moveto(#12.24,.1)^^A
+% \curveto(#12.3,-1)(#12,-1.2)(#11.5,-1.2)^^A
+% \curveto(#11.3,-1.2)(#11.125,-1.3)(#11.125,-1.5)^^A
+% \strokepath
+% ^^A Jaw
+% \moveto(#11.875,-1.35)^^A
+% \curveto(#11.86,-1.8)(#11.8,-1.5)(#11.65,-1.95)^^A
+% \curveto(#11.5,-2.4)(#11.5,-2.75)(#11.2,-2.9)^^A
+% \curveto(#1.9,-3.05)(#11,-3.2)(#1.3,-3.1)^^A
+% \strokepath
+% }
+% \newcommand*{\semilargeskullinnerjaw}[1]{^^A
+% \moveto(#11.5,-1.35)^^A
+% \curveto(#11.35,-1.5)(#11.5,-2.25)(#11.125,-2.25)^^A
+% \strokepath
+% }
+% \newcommand*{\semilargeskullteeth}[2]{^^A
+% \moveto(#1.75,-2.25)^^A
+% \curveto(#1.65,-2.5)(#1.55,-2.5)(#1.45,-2.3)^^A
+% \curveto(#1.35,-2.05)(#1.4,-2)(#1.6,-2)^^A
+% \curveto(#1.8,-2)(#1.8,-2.05)(#1.75,-2.25)^^A
+% \strokepath
+% \moveto(#1.35,-2.3)^^A
+% \curveto(#1.25,-2.6)(#1.1,-2.65)(#1.05,-2.3)^^A
+% \curveto(#1.05,-2.05)(0,-2.05)(#1.2,-2.05)^^A
+% \curveto(#1.4,-2.05)(#1.42,-2)(#1.35,-2.3)^^A
+% \strokepath
+% \moveto(#11.12,-1.6)^^A
+% \curveto(#11,-1.3)(#1.9,-1.3)(#1.75,-1.6)^^A
+% \curveto(#11,-3)(#11,-3)(#11.12,-1.5)^^A
+% \strokepath
+% \moveto(#1.7,-1.6)^^A
+% \curveto(#1.6,-1.4)(#1.5,-1.4)(#1.45,-1.65)^^A
+% \curveto(#1.45,-1.85)(#1.4,-1.95)(#1.55,-1.95)^^A
+% \curveto(#1.85,-1.95)(#1.75,-1.75)(#1.7,-1.6)^^A
+% \strokepath
+% \moveto(#1.4,-1.65)^^A
+% \curveto(#1.3,-1.4)(#1.1,-1.4)(#1.05,-1.7)^^A
+% \curveto(#1.05,-1.9)(#2.05,-2)(#1.225,-2)^^A
+% \curveto(#1.5,-2)(#1.45,-1.9)(#1.4,-1.65)
+% \strokepath
+% }
+% \newcommand*{\semilargeskullthinlines}[1]{^^A
+% \moveto(#1.8,.7)^^A
+% \curveto(#1.4,.7)(#1.4,.9)(#1.2,.7)^^A
+% \curveto(#1.1,.6)(#1.2,.4)(#1.2,.3)^^A
+% \strokepath
+% \cbezier(#11.3,.7)(#11.5,.7)(#11.5,.75)(#11.75,.5)^^A
+% }
+%
+% \centering
+%
+% The binary operator variant:\\*[\medskipamount]
+% \begin{picture}(3.2,4)(-1.6,-2)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-2,-2)(1,0){5}{\line(0,1){4}}
+% \multiput(-2,-2)(0,1){5}{\line(1,0){4}}
+% \color{black}
+% \roundcap
+% \linethickness{.7pt}
+% \semibinaryskullteeth-+
+% \semibinaryskullteeth+-
+% \linethickness{1.3pt}
+% \binaryskullnose{5}{1}{2}{5}{15}{4}{1}{1}
+% \semibinaryskullcontour-
+% \semibinaryskullcontour+
+% \end{picture}
+%
+% \bigskip\bigskip
+%
+% The small variant:\\*[\medskipamount]
+% \begin{picture}(4,4)(-2,-2)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-2,-2)(1,0){5}{\line(0,1){4}}
+% \multiput(-2,-2)(0,1){5}{\line(1,0){4}}
+% \color{black}
+% \roundcap
+% \linethickness{.8pt}
+% \semismallskullteeth-+
+% \semismallskullteeth+-
+% \linethickness{2pt}
+% \binaryskullnose{75}{15}{3}{75}{225}{6}{15}{15}
+% \semismallskullcontour-
+% \semismallskullcontour+
+% \semismallskulljaw-
+% \semismallskulljaw+
+% \linethickness{1.2pt}
+% \semismallskullinnerjaw-
+% \semismallskullinnerjaw+
+% \end{picture}
+%
+% \bigskip\bigskip
+%
+% The large variant:\\*[\medskipamount]
+% \begin{picture}(9,8)(-4.5,-4)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-4,-4)(1,0){9}{\line(0,1){8}}
+% \multiput(-4,-4)(0,1){9}{\line(1,0){8}}
+% \color{black}
+% \roundcap
+% \linethickness{1pt}
+% \semilargeskullteeth-+
+% \semilargeskullteeth+-
+% \linethickness{3pt}
+% \largeskullnose
+% {1.125}{.1}{.5}{.3375}{.9}{.147}{.7}{.2}{.4}
+% \cbezier(-2,2)(-1.25,3.5)(1.25,3.5)(2,2)
+% \semilargeskullcontour-
+% \semilargeskullcontour+
+% \cbezier(-.3,-3.1)(0,-3)(0,-3)(.3,-3.1)
+% \linethickness{1.8pt}
+% \semilargeskullinnerjaw-
+% \semilargeskullinnerjaw+
+% \linethickness{.5pt}
+% \semilargeskullthinlines-
+% \semilargeskullthinlines+
+% \end{picture}
+%
+% \caption{Sketches of the skulls}
+% \label{fig:skulls}
+% \end{figure}
+%
+% As you can see in figure~\ref{fig:pumpkins}, skulls too come in three
+% variants: a binary operator and the two versions (both for display and
+% nondisplay math) of a ``large'' operator. Below, the macros for each
+% version are preceded by one or two useful ``subroutines'', that draw some
+% patterns that appear more than once in the picture.
+%
+% \begin{macro}{\@HwM@large@skull@nose}
+% Subroutine that draws the (hole corresponding to the) nose in the variant
+% of the skull that is used for a ``large'' operator typeset in display
+% style. Parameters are suitable points coordinates.
+% \begin{macrocode}
+\newcommand*\@HwM@large@skull@nose[9]{%
+ \moveto(0,-#1)%
+ \curveto(-#2,-#1)(-#3,-#1)(-#4,-#5)%
+ \curveto(-#6,-#7)(-#8,-#9)(0,-#9)%
+ \curveto(#8,-#9)(#6,-#7)(#4,-#5)%
+ \curveto(#3,-#1)(#2,-#1)(0,-#1)%
+ \fillpath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@large@skull@profile}
+% Subroutine that draws the outline and the outer part of the jaw in the
+% variant of the skull that is used for a ``large'' operator typeset in
+% display style. Argument~\#1 is either \texttt{-} or~\texttt{+}, depending
+% on which half of the skull you want to draw.
+% \begin{macrocode}
+\newcommand*\@HwM@large@skull@profile[1]{%
+ \moveto(#1.3375,0)%
+ \curveto(#1.3375,.225)(#1.3375,.4725)(#1.9,.45)%
+ \curveto(#11.35,.4275)(#11.5525,.225)(#11.575,0)%
+ \curveto(#11.5975,-.225)(#11.35,-.675)(#11.125,-.675)%
+ \curveto(#1.9,-.675)(#1.3375,-.45)(#1.3375,0)%
+ \fillpath
+ \cbezier(#12,2)(#12.1,1.8)(#12.7,1.125)(#12.25,0)%
+ \moveto(#12.24,.1)%
+ \curveto(#12.3,-1)(#12,-1.2)(#11.5,-1.2)%
+ \curveto(#11.3,-1.2)(#11.125,-1.3)(#11.125,-1.5)%
+ \strokepath
+% \end{macrocode}
+% The outer contour of the jaw:
+% \begin{macrocode}
+ \moveto(#11.875,-1.35)%
+ \curveto(#11.86,-1.8)(#11.8,-1.5)(#11.65,-1.95)%
+ \curveto(#11.5,-2.4)(#11.5,-2.75)(#11.2,-2.9)%
+ \curveto(#1.9,-3.05)(#11,-3.2)(#1.3,-3.1)%
+ \strokepath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@large@skull@innerjaw}
+% Subroutine that draws the inner part of the jaw in the variant of the skull
+% that is used for a ``large'' operator typeset in display style.
+% Argument~\#1 is either \texttt{-} or~\texttt{+}, depending on which half of
+% the skull you want to draw.
+% \begin{macrocode}
+\newcommand*\@HwM@large@skull@innerjaw[1]{%
+ \moveto(#11.5,-1.35)%
+ \curveto(#11.35,-1.5)(#11.5,-2.25)(#11.125,-2.25)%
+ \strokepath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@large@skull@teeth}
+% Subroutine for drawing the teeth in the variant of the skull that is used
+% for a ``large'' operator typeset in display style. Argument~\#1 is either
+% \texttt{-} or~\texttt{+}, depending on which half of the skull you want to
+% draw; then, argument~\#2 must always be the opposite sign (that is, either
+% \texttt{+} or~\texttt{-}, respectively).
+% \begin{macrocode}
+\newcommand*\@HwM@large@skull@teeth[2]{%
+ \moveto(#1.75,-2.25)%
+ \curveto(#1.65,-2.5)(#1.55,-2.5)(#1.45,-2.3)%
+ \curveto(#1.35,-2.05)(#1.4,-2)(#1.6,-2)%
+ \curveto(#1.8,-2)(#1.8,-2.05)(#1.75,-2.25)%
+ \strokepath
+ \moveto(#1.35,-2.3)%
+ \curveto(#1.25,-2.6)(#1.1,-2.65)(#1.05,-2.3)%
+ \curveto(#1.05,-2.05)(0,-2.05)(#1.2,-2.05)%
+ \curveto(#1.4,-2.05)(#1.42,-2)(#1.35,-2.3)%
+ \strokepath
+ \moveto(#1.7,-1.6)%
+ \curveto(#1.6,-1.4)(#1.5,-1.4)(#1.45,-1.65)%
+ \curveto(#1.45,-1.85)(#1.4,-1.95)(#1.55,-1.95)%
+ \curveto(#1.85,-1.95)(#1.75,-1.75)(#1.7,-1.6)%
+ \strokepath
+ \moveto(#11.12,-1.6)%
+ \curveto(#11,-1.3)(#1.9,-1.3)(#1.75,-1.6)%
+ \curveto(#11,-3)(#11,-3)(#11.12,-1.5)%
+ \strokepath
+ \moveto(#1.4,-1.65)%
+ \curveto(#1.3,-1.4)(#1.1,-1.4)(#1.05,-1.7)%
+ \curveto(#1.05,-1.9)(#2.05,-2)(#1.225,-2)%
+ \curveto(#1.5,-2)(#1.45,-1.9)(#1.4,-1.65)
+ \strokepath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@large@skull@brows}
+% Subroutine for drawing the brows in the variant of the skull that is used
+% for a ``large'' operator typeset in display style. Argument~\#1 is either
+% \texttt{-} or~\texttt{+}, depending on which half of the skull you want to
+% draw.
+% \begin{macrocode}
+\newcommand*\@HwM@large@skull@brows[1]{%
+ \moveto(#1.8,.7)%
+ \curveto(#1.4,.7)(#1.4,.9)(#1.2,.7)%
+ \curveto(#1.1,.6)(#1.2,.4)(#1.2,.3)%
+ \strokepath
+ \cbezier(#11.3,.7)(#11.5,.7)(#11.5,.75)(#11.75,.5)%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% Admittedly, not all these subroutines were actually needed; but I~wrote the
+% code this way when I~dashed off the skethces, and I~was too lazy to
+% streamline it afterwards, when copying it to this package!
+%
+% \begin{macro}{\@HwM@large@skull}
+% Private version of the macro that draws the skull correspondng to a
+% ``large'' operator used in display math mode. Arguments:
+% \begin{paramlist}
+% \param
+% main drawing thickn., in units of the default-rule-thickness
+% "\fontdimen";\\
+% \param
+% line thickness for drawing the inner of the jaw, in the same units;\\
+% \param
+% line thickness for drawing the teeth, in the same units;\\
+% \param
+% line thickness for drawing the brows, in points~(\texttt{pt}).
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@large@skull[4]{%
+ \begin{@HwM@bigop@picture}\displaystyle \textfont {6}{-3}%
+ \roundcap
+ \linethickness{#3\@HwM@thickness@units@for \textfont}%
+ \@HwM@large@skull@teeth-+%
+ \@HwM@large@skull@teeth+-%
+ \linethickness{#1\@HwM@thickness@units@for \textfont}%
+ \@HwM@large@skull@nose
+ {1.125}{.1}{.5}{.3375}{.9}{.147}{.7}{.2}{.4}%
+ \cbezier(-2,2)(-1.25,3.5)(1.25,3.5)(2,2)%
+ \@HwM@large@skull@profile-%
+ \@HwM@large@skull@profile+%
+ \cbezier(-.3,-3.1)(0,-3)(0,-3)(.3,-3.1)%
+ \linethickness{#2\@HwM@thickness@units@for \textfont}%
+ \@HwM@large@skull@innerjaw-%
+ \@HwM@large@skull@innerjaw+%
+ \linethickness{#4\p@}%
+ \@HwM@large@skull@brows-%
+ \@HwM@large@skull@brows+%
+ \end{@HwM@bigop@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Large@Skull}
+% Public version of the above; requires no parameters.
+% \begin{macrocode}
+\newcommand*\@HwM@Large@Skull{%
+ \@HwM@choose@thicknesses \@HwM@large@skull
+ {{1.5}{.9}{.3}{.075}}%
+ {{2}{1.2}{.4}{.1}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@skull@nose}
+% Subroutine that draws the (hole corresponding to the) variant of the nose
+% that is shared between the binary operator and the nondisplay version of
+% the ``large'' operator. The parameters are suitable point coordinates.
+% \begin{macrocode}
+\newcommand*\@HwM@small@skull@nose[8]{%
+ \moveto(0,-.#1)%
+ \curveto(-.#2,-.#1)(-.#3,-.#4)(-.#5,-.#6)%
+ \curveto(-.#7,-.#8)(.#7,-.#8)(.#5,-.#6)%
+ \curveto(.#3,-.#4)(.#2,-.#1)(0,-.#1)%
+ \fillpath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@skull@profile}
+% Subroutine that draws the outline and the outer part of the jaw in the
+% variant of the skull that is used for a ``large'' operator typeset in
+% \emph{non}-display style. Argument~\#1 is either \texttt{-} or~\texttt{+},
+% depending on which half of the skull you want to draw.
+% \begin{macrocode}
+\newcommand*\@HwM@small@skull@profile[1]{%
+ \moveto(#1.225,0)%
+ \curveto(#1.225,.15)(#1.225,.315)(#1.6,.3)%
+ \curveto(#1.9,.285)(#11.035,.15)(#11.05,0)%
+ \curveto(#11.065,-.15)(#1.9,-.45)(#1.75,-.45)%
+ \curveto(#1.6,-.45)(#1.225,-.3)(#1.225,0)%
+ \fillpath
+ \cbezier(0,2)(#11.5,2)(#11.8,0.75)(#11.5,0)%
+ \cbezier(#11.5,0)(#11.575,-1.35)(#1.75,-.45)(#1.75,-1)%
+% \end{macrocode}
+% The outer contour of the jaw:
+% \begin{macrocode}
+ \moveto(#11.25,-.9)%
+ \curveto(#11.24,-1.2)(#11.2,-1)(#11.1,-1.3)%
+ \curveto(#11,-1.6)(#11,-1.8)(#1.75,-1.9)%
+ \curveto(0,-2.1)(#1.3,-2)(0,-2)%
+ \strokepath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@skull@innerjaw}
+% Subroutine that draws the inner part of the jaw in the variant of the skull
+% that is used for a ``large'' operator typeset in display style.
+% Argument~\#1 is either \texttt{-} or~\texttt{+}, depending on which half of
+% the skull you want to draw.
+% \begin{macrocode}
+\newcommand*\@HwM@small@skull@innerjaw[1]{%
+ \moveto(#11,-.9)%
+ \curveto(#1.9,-1)(#11,-1.5)(#1.75,-1.5)%
+ \strokepath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@skull@teeth}
+% Subroutine for drawing the teeth in the variant of the skull that is used
+% for a ``large'' operator which gets typeset in \emph{non}-display style.
+% Argument~\#1 is either \texttt{-} or~\texttt{+}, depending on which half of
+% the skull you want to draw; then, argument~\#2 must always be the opposite
+% sign (that is, either \texttt{+} or~\texttt{-}, respectively).
+% \begin{macrocode}
+\newcommand*\@HwM@small@skull@teeth[2]{%
+ \moveto(#1.5,-1.5)%
+ \curveto(#1.47,-1.65)(#1.35,-1.6)(#1.3,-1.55)%
+ \curveto(#1.15,-1.25)(#1.65,-1.25)(#1.5,-1.5)%
+ \strokepath
+ \moveto(#1.25,-1.55)%
+ \curveto(#1.2,-1.7)(#1.04,-1.7)(#1.03,-1.55)%
+ \curveto(#2.1,-1.3)(#1.35,-1.3)(#1.25,-1.55)%
+ \strokepath
+ \moveto(#1.45,-1)%
+ \curveto(#1.4,-.9)(#1.3,-.9)(#1.285,-1.05)%
+ \curveto(#1.2,-1.35)(#1.6,-1.35)(#1.45,-1)%
+ \strokepath
+ \moveto(#1.75,-1)%
+ \curveto(#1.65,-.9)(#1.6,-.9)(#1.5,-1)%
+ \curveto(#1.6,-2)(#1.7,-2)(#1.75,-1)%
+ \strokepath
+ \moveto(#1.25,-1.05)%
+ \curveto(#1.2,-.9)(#1.04,-.9)(#1.03,-1.05)%
+ \curveto(#2.08,-1.4)(#1.35,-1.4)(#1.25,-1.05)%
+ \strokepath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% The same remark, as the one we made above, about the redundancy of these
+% subroutines (and about my laziness!\@) applies here.
+%
+% \begin{macro}{\@HwM@small@skull}
+% Private version of the macro that draws the skull correspondng to a
+% ``large'' operator used in \emph{non}-display math mode. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont");\\
+% \param
+% main drawing thickn., in units of the default-rule-thickness
+% "\fontdimen";\\
+% \param
+% line thickness for drawing the inner of the jaw, in the same units;\\
+% \param
+% line thickness for drawing the teeth, in the same units.
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@small@skull[5]{%
+ \begin{@HwM@bigop@picture}#1#2{3.48}{-1.74}%
+ \roundcap
+ \linethickness{#5\@HwM@thickness@units@for #2}%
+ \@HwM@small@skull@teeth-+%
+ \@HwM@small@skull@teeth+-%
+ \linethickness{#3\@HwM@thickness@units@for #2}%
+ \@HwM@small@skull@nose{75}{15}{3}{75}{225}{6}{15}{15}%
+ \@HwM@small@skull@profile-%
+ \@HwM@small@skull@profile+%
+ \linethickness{#4\@HwM@thickness@units@for #2}%
+ \@HwM@small@skull@innerjaw-%
+ \@HwM@small@skull@innerjaw+%
+ \end{@HwM@bigop@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Small@Skull}
+% Public version of the above, with the following arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@Small@Skull[2]{%
+ \@HwM@choose@thicknesses{\@HwM@small@skull #1#2}%
+ {{}{.6}{.25}}%
+ {{1.333333}{.7}{.3}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@binop@skull@profile}
+% Subroutine that draws the outline of the variant of the skull that is used
+% for a binary operator (in whatever style). Argument~\#1 is either
+% \texttt{-} or~\texttt{+}, depending on which half of the skull you want to
+% draw.
+% \begin{macrocode}
+\newcommand*\@HwM@binop@skull@profile[1]{%
+ \moveto(#1.15,0)%
+ \curveto(#1.15,.1)(#1.15,.21)(#1.4,.2)%
+ \curveto(#1.6,.19)(#1.69,.1)(#1.7,0)%
+ \curveto(#1.71,-.1)(#1.6,-.3)(#1.5,-.3)%
+ \curveto(#1.4,-.3)(#1.15,-.2)(#1.15,0)%
+ \fillpath
+ \cbezier(0,1.333336)(#11,1.333336)(#11.2,0.5)(#11,0)%
+ \cbezier(#11,0)(#11.05,-.9)(#1.5,-.3)(#1.5,-.65)%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@binop@skull@teeth}
+% Subroutine for drawing the teeth in the variant of the skull that is used
+% for a binary operator. Argument~\#1 is either \texttt{-} or~\texttt{+},
+% depending on which half of the skull you want to draw; then, argument~\#2
+% must always be the opposite sign (that is, either \texttt{+} or~\texttt{-},
+% respectively).
+% \begin{macrocode}
+\newcommand*\@HwM@binop@skull@teeth[2]{%
+ \moveto(#1.33,-.7)%
+ \curveto(#1.3,-.6)(#1.22,-.6)(#1.19,-.75)%
+ \curveto(#1.15,-.9)(#1.38,-.9)(#1.33,-.7)%
+ \strokepath
+ \moveto(#1.5,-.7)%
+ \curveto(#1.45,-.6)(#1.4,-.6)(#1.35,-.7)%
+ \curveto(#1.4,-1.2)(#1.5,-1.2)(#1.5,-.7)%
+ \strokepath
+ \moveto(#1.17,-.75)%
+ \curveto(#1.13,-.65)(#1.05,-.62)(#1.02,-.75)%
+ \curveto(#2.03,-.95)(#1.22,-.95)(#1.17,-.75)%
+ \strokepath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@binop@skull}
+% Private version of the macro that draws the skull for a binary operator.
+% Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% font selector (\eg "\textfont");\\
+% \param
+% main drawing thickn., in units of the default-rule-thickness
+% "\fontdimen";\\
+% \param
+% line thickness for drawing the teeth, in the same units.
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@binop@skull[4]{%
+ \begin{@HwM@oplus@picture}#1#2{2.48}{-1.24}%
+ \roundcap
+ \linethickness{#4\@HwM@thickness@units@for #2}%
+ \@HwM@binop@skull@teeth-+%
+ \@HwM@binop@skull@teeth+-%
+ \linethickness{#3\@HwM@thickness@units@for #2}%
+ \@HwM@small@skull@nose{5}{1}{2}{5}{15}{4}{1}{1}%
+ \@HwM@binop@skull@profile-%
+ \@HwM@binop@skull@profile+%
+ \end{@HwM@oplus@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Binop@Skull}
+% Public version of the above, with the following arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@Binop@Skull[2]{%
+ \@HwM@choose@thicknesses{\@HwM@binop@skull #1#2}%
+ {{.6}{.2}}%
+ {{.9}{.266667}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Drawing the clouds}
+%
+% Clouds are relatively simple to deal with: they are treated similarly to
+% fractions, in that they are typeset in a larger version, used only for
+% "\displaystyle" math, and in a smaller one, used in all the other cases.
+% Figure~\ref{fig:cloud} sketches both variants.
+%
+% \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{1.5pt}
+% \roundcap
+% \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{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{2pt}
+% \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{picture}
+%
+% \caption{Sketches of the cloud}
+% \label{fig:cloud}
+% \end{figure}
+%
+% By good fortune, clouds do not require any subroutine\ldots
+%
+% \begin{macro}{\@HwM@large@cloud}
+% This is the private version of the macro that draws the larger cloud.
+% Argument:
+% \begin{paramlist}
+% \param
+% drawing thickness, in units of the default-rule-thickness "\fontdimen".
+% \end{paramlist}
+% \begin{macrocode}
+\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}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Large@Cloud}
+% Public version of the above; requires no parameters.
+% \begin{macrocode}
+\newcommand*\@HwM@Large@Cloud{%
+ \@HwM@choose@thicknesses \@HwM@large@cloud
+ {{.8}}%
+ {{1.6}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@small@cloud}
+% Private version of the macro that draws the smaller cloud (which has a
+% little fewer details than the larger one). Arguments:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\scriptfont");\\
+% \param
+% drawing thickness, in units of the default-rule-thickness "\fontdimen".
+% \end{paramlist}
+% \begin{macrocode}
+\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}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Small@Cloud}
+% Public version of the above. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\scriptstyle");\\
+% \param
+% font selector (\eg "\scriptfont").
+% \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@Cloud[2]{%
+ \@HwM@choose@thicknesses{\@HwM@small@cloud #2}%
+ {{.5}}%
+ {{1.2}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% That's all: as we promised, this has been a quick one!
+%
+% \subsubsection{Drawing the ghosts}
+%
+% For ghosts, I~imagined a r\^{o}le as ordinary symbols, and nothing else;
+% therefore, they exist in only one size, but, in return, they can be seen
+% from three different views (left, front, and right), as
+% figure~\ref{fig:ghosts} depicts. From the implementation viewpoint, only
+% two variants need to be defined: a ``symmetric ghost'', that corresponds to
+% the front view, and an ``asymmetric ghost'', which yields the left and the
+% right views through the same mechanism that toggles, for example, between
+% the straight and the reverse witch.
+%
+% \begin{figure}[tp]
+% \newcommand*{\SymmetricGhostContour}[8]{^^A
+% \cbezier(-#1,#2)(-#3,#4)(-#3,#5)(-#3,#6)^^A
+% \Line(-#3,#6)(-#3,#7)^^A
+% \cbezier(#1,#2)(#3,#4)(#3,#5)(#3,#6)^^A
+% \Line(#3,#6)(#3,#7)^^A
+% \cbezier(-#3,#7)(-#3,#8)(#3,#8)(#3,#7)^^A
+% }
+% \newcommand*{\SymmetricGhostBorder}[8]{^^A
+% \cbezier(-#1,#2)(-#3,#4)(-#5,#6)(-#7,#2)^^A
+% \qbezier(-#7,#2)(0,#8)(#7,#2)^^A
+% \cbezier(#1,#2)(#3,#4)(#5,#6)(#7,#2)^^A
+% }
+% \newcommand*{\SymmetricGhostEyes}[3]{^^A
+% \put(-#1,#2){\circle*{#3}}^^A
+% \put(#1,#2){\circle*{#3}}^^A
+% }
+% \newcommand*{\AsymmetricGhost}[2]{^^A
+% \roundcap
+% \linethickness{1.5pt}^^A
+% \cbezier(#11.75,-1.5)(#11,-1)(#1.7,-.5)(#1.5,0)^^A
+% \cbezier(#1.5,0)(#1.3,.5)(0,1.6)(#21,1.6)^^A
+% \cbezier(#21,1.6)(#21.8,1.6)(#21.8,.9)(#21.8,.6)^^A
+% \cbezier(#21.8,.6)(#21.8,-.3)(#2.9,-.7)(#21.25,-1.5)^^A
+% \linethickness{1pt}^^A
+% \cbezier(#11.75,-1.5)(#11.4,-1.2)(#11.1,-1.8)(#1.75,-1.5)^^A
+% \cbezier(#1.75,-1.5)(#1.4,-1.2)(#1.1,-1.8)(#2.25,-1.5)^^A
+% \cbezier(#2.25,-1.5)(#2.6,-1.2)(#2.9,-1.8)(#21.25,-1.5)^^A
+% \put(#21.2,.7){\circle*{.4}}^^A
+% }
+%
+% \centering
+% \addtolength\leftskip {-2cm}
+% \addtolength\rightskip{-2cm}
+%
+% Only the small variant is defined:\\*[\bigskipamount]
+% \begin{picture}(4,4)(-2,-2)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-2,-2)(1,0){5}{\line(0,1){4}}
+% \multiput(-2,-2)(0,1){5}{\line(1,0){4}}
+% \color{black}
+% \AsymmetricGhost+-
+% \end{picture}\qquad
+% \begin{picture}(4,4)(-2,-2)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-2,-2)(1,0){5}{\line(0,1){4}}
+% \multiput(-2,-2)(0,1){5}{\line(1,0){4}}
+% \color{black}
+% \roundcap
+% \linethickness{1.5pt}
+% \SymmetricGhostContour{1.5}{-1.5}{1}{-1}{-.5}{0}{.5}{2}
+% \linethickness{1pt}
+% \SymmetricGhostBorder{1.5}{-1.5}{1.1}{-1.1}{.7}{-1.9}{.3}{-1.2}
+% \SymmetricGhostEyes{.4}{.7}{.4}
+% \end{picture}\qquad
+% \begin{picture}(4,4)(-2,-2)
+% \linethickness{.1pt}
+% \color{guidelines}
+% \multiput(-2,-2)(1,0){5}{\line(0,1){4}}
+% \multiput(-2,-2)(0,1){5}{\line(1,0){4}}
+% \color{black}
+% \AsymmetricGhost-+
+% \end{picture}\par
+%
+% \caption{Sketches of the ghosts}
+% \label{fig:ghosts}
+% \end{figure}
+%
+% For ghosts, again, we do have some subroutines; and, again, some of these
+% could actually be inserted inline.
+%
+% \begin{macro}{\@HwM@symm@ghost@contour}
+% Subroutine that draws the thicker part of a symmetric ghost's contour.
+% Parameters are suitable point coordinates.
+% \begin{macrocode}
+\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)%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@symm@ghost@border}
+% Subroutine that draws the lower border of a symmetric ghost's sheet (the
+% thinner part of its contour). Parameters are suitable point coordinates.
+% \begin{macrocode}
+\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)%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@symm@ghost@eyes}
+% Subroutine that draws the eyes of a symmetric ghost. The parameters are
+% self-explanatory.
+% \begin{macrocode}
+\newcommand*\@HwM@symm@ghost@eyes[3]{%
+ \put(-#1,#2){\circle*{#3}}%
+ \put(#1,#2){\circle*{#3}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@symmetric@ghost}
+% Private version of the macro that draws the symmetric ghost. Arguments:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont");\\
+% \param
+% contour thickness, in units of the default-rule-thickness
+% "\fontdimen";\\
+% \param
+% lower border thickness, in the same units.
+% \end{paramlist}
+% \begin{macrocode}
+\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}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Symmetric@Ghost}
+% Public version of the above. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% font selector (\eg "\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@Symmetric@Ghost[2]{%
+ \@HwM@choose@thicknesses{\@HwM@symmetric@ghost #2}%
+ {{.9}{.6}}%
+ {{1.8}{1.2}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@asymmetric@ghost}
+% Private version of the macro that draws the asymmetric ghost. Arguments:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont");\\
+% \param
+% contour thickness, in units of the default-rule-thickness
+% "\fontdimen";\\
+% \param
+% lower border thickness, in the same units.
+% \end{paramlist}
+% \begin{macrocode}
+\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}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Asymmetric@Ghost}
+% Public version of the above. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% font selector (\eg "\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@Asymmetric@Ghost[2]{%
+ \@HwM@choose@thicknesses{\@HwM@asymmetric@ghost #2}%
+ {{.9}{.6}}%
+ {{1.8}{1.2}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Drawing the bats}
+%
+% We've finally got to the last of our characters (at least for this
+% version): the bat. Bats are rendered as filled, as opposed to stroked,
+% black shapes, and therefore it is impossible to differentiate the normal
+% and the bold version by changing the thickness of the strokes (because
+% there aren't any): the shape itself needs to be made slightly larger.
+% Besides this, as in the case of ghosts we have designed a ``symmetric'' bat
+% and an ``asymmetric'' one, where the latter can be drawn in two opposite
+% orientations: this makes a total of six possible variants, which are
+% portrayed in figures \ref{fig:s-bats} and~\ref{fig:a-bats}. The reference
+% lines help you spot the differences between the bold and the normal
+% versions.
+%
+% \begin{figure}[tp]
+% \newcommand*{\BatWing}[1]{^^A
+% \moveto(#1.7,0)^^A
+% \curveto(#11.5,.1)(#12.2,.5)(#12,1)^^A
+% \curveto(#12.5,.5)(#12.9,0)(#12.9,-.5)^^A
+% \curveto(#12.8,0)(#12,-.5)(#12.25,-1)^^A
+% \curveto(#12,-.5)(#11.7,-.3)(#11.5,-.7)^^A
+% \curveto(#11.4,-.5)(#11.2,-.3)(#11,-.5)^^A
+% \curveto(#1.9,-.4)(#1.7,-.4)(#1.5,-.5)^^A
+% \closepath
+% \fillpath
+% }
+% \newcommand*{\BoldBatWing}[1]{^^A
+% \moveto(#1.7,.1)^^A
+% \curveto(#11.5,.2)(#12.25,.6)(#12,1.1)^^A
+% \curveto(#12.6,.5)(#13,0)(#13,-.6)^^A
+% \curveto(#12.8,0)(#12,-.6)(#12.25,-1.1)^^A
+% \curveto(#12,-.6)(#11.7,-.4)(#11.5,-.8)^^A
+% \curveto(#11.4,-.6)(#11.2,-.4)(#11,-.6)^^A
+% \curveto(#1.9,-.5)(#1.7,-.5)(#1.5,-.5)^^A
+% \closepath
+% \fillpath
+% }
+%
+% \newcommand*{\Bat}{^^A
+% \moveto(-.5,-.5)^^A
+% \curveto(-.4,-.6)(-.2,-.7)(-.2,-1)^^A
+% \curveto(-.1,-.7)(.1,-.7)(.2,-1)^^A
+% \curveto(.2,-.7)(.4,-.6)(.5,-.5)^^A
+% \closepath
+% \fillpath
+% \BatWing-^^A
+% \BatWing+^^A
+% \moveto(.5,0)^^A
+% \circlearc{.35}{0}{.15}{0}{180}^^A
+% \lineto(-.2,0)^^A
+% \circlearc{-.35}{0}{.15}{0}{180}^^A
+% \lineto(-.75,0)^^A
+% \curveto(-.75,.45)(-.7,.5)(-.5,1)^^A
+% \circlearc{0}{1}{.5}{180}{360}^^A
+% \curveto(.7,.5)(.75,.45)(.75,0)^^A
+% \closepath
+% \fillpath
+% \moveto(-.75,0)^^A
+% \circlearc{0}{0}{.75}{180}{360}^^A
+% \lineto(.5,0)^^A
+% \circlearc{.35}{0}{.15}{360}{180}^^A
+% \lineto(-.2,0)^^A
+% \circlearc{-.35}{0}{.15}{360}{180}^^A
+% \closepath
+% \fillpath
+% }
+% \newcommand*{\BoldBat}{^^A
+% \moveto(-.6,-.5)^^A
+% \curveto(-.5,-.6)(-.3,-.7)(-.3,-1.1)^^A
+% \curveto(-.1,-.7)(.1,-.7)(.3,-1.1)^^A
+% \curveto(.3,-.7)(.5,-.6)(.6,-.5)^^A
+% \closepath
+% \fillpath
+% \BoldBatWing-^^A
+% \BoldBatWing+^^A
+% \moveto(.5,0)^^A
+% \circlearc{.35}{0}{.15}{0}{180}^^A
+% \lineto(-.2,0)^^A
+% \circlearc{-.35}{0}{.15}{0}{180}^^A
+% \lineto(-.8,0)^^A
+% \curveto(-.8,.5)(-.7,.5)(-.55,1.1)^^A
+% \circlearc{0}{1.1}{.55}{180}{360}^^A
+% \curveto(.7,.5)(.8,.5)(.8,0)^^A
+% \closepath
+% \fillpath
+% \moveto(-.8,0)^^A
+% \circlearc{0}{0}{.8}{180}{360}^^A
+% \lineto(.5,0)^^A
+% \circlearc{.35}{0}{.15}{360}{180}^^A
+% \lineto(-.2,0)^^A
+% \circlearc{-.35}{0}{.15}{360}{180}^^A
+% \closepath
+% \fillpath
+% }
+%
+% \centering
+%
+% The symmetric bat,
+% in the \texttt{normal}\ldots\\*[\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}
+% \Bat
+% \end{picture}
+%
+% \bigskip\bigskip\bigskip
+%
+% \ldots and in the \texttt{bold} math version.\\*[\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}
+% \BoldBat
+% \end{picture}
+%
+% \caption{Sketches of the symmetric bats}
+% \label{fig:s-bats}
+% \end{figure}
+%
+% \begin{figure}[tp]
+% \newcommand*{\AsymmBat}{^^A
+% \moveto(\-.5,.2)^^A
+% \curveto(\-1.5,.3)(\-2.2,.5)(\-1.8,1)^^A
+% \curveto(\-2.5,.5)(\-2.9,0)(\-2.9,-.5)^^A
+% \curveto(\-2.7,0)(\-2,-.25)(\-2,-.8)^^A
+% \curveto(\-2,-.5)(\-1.6,-.25)(\-1.4,-.5)^^A
+% \curveto(\-1.4,-.2)(\-1.2,-.1)(\-1,-.3)^^A
+% \curveto(\-1,-.1)(\-.7,-.1)(\-.6,-.1)^^A
+% \closepath
+% \fillpath
+% \moveto(\+.9,0)^^A
+% \curveto(\+2,-.1)(\+2.2,.5)(\+2,.7)^^A
+% \curveto(\+2.5,.6)(\+3.2,0)(\+2.9,-.7)^^A
+% \curveto(\+2.6,-.2)(\+2,-.5)(\+2,-1)^^A
+% \curveto(\+2,-.5)(\+1.7,-.4)(\+1.5,-.7)^^A
+% \curveto(\+1.6,-.4)(\+1.3,-.2)(\+1.1,-.5)^^A
+% \curveto(\+1.1,-.3)(\+1,-.3)(\+.8,-.3)^^A
+% \closepath
+% \fillpath
+% \moveto(\+.8,-.1)^^A
+% \curveto(\+.85,.08)(\+.65,.13)(\+.6,-.05)^^A
+% \lineto(\+.3,0)^^A
+% \curveto(\+.35,.2)(\+.05,.3)(0,.1)^^A
+% \lineto(\-.8,0)^^A
+% \curveto(\-.7,.3)(\-.4,.7)(\+.25,1)^^A
+% \curveto(\+.2,.4)(\+.8,.3)(\+1,.9)^^A
+% \curveto(\+1.1,.7)(\+1.1,.2)(\+1,0)^^A
+% \closepath
+% \fillpath
+% \moveto(\+.8,-.1)^^A
+% \curveto(\+.75,-.28)(\+.55,-.23)(\+.6,-.05)^^A
+% \lineto(\+.3,0)^^A
+% \curveto(\+.25,-.18)(\-.05,-.08)(0,.1)^^A
+% \lineto(\-.8,0)^^A
+% \curveto(\-.9,-.3)(\-.8,-.6)(\-1,-.9)^^A
+% \curveto(\-.8,-.6)(\-.4,-.7)(\-.6,-1)^^A
+% \curveto(\-.2,-.8)(\+.2,-.82)(\+.3,-.8)^^A
+% \curveto(\+.85,-.69)(\+.99,-.02)(\+1,0)^^A
+% \closepath
+% \fillpath
+% }
+% \newcommand*{\BoldAsymmBat}{^^A
+% \moveto(\-.5,.3)^^A
+% \curveto(\-1.5,.4)(\-2.2,.6)(\-1.9,1.1)^^A
+% \curveto(\-2.6,.6)(\-3,0)(\-3,-.6)^^A
+% \curveto(\-2.6,-.1)(\-2,-.4)(\-2,-.9)^^A
+% \curveto(\-2,-.6)(\-1.6,-.35)(\-1.4,-.6)^^A
+% \curveto(\-1.4,-.3)(\-1.2,-.2)(\-1,-.4)^^A
+% \curveto(\-1,-.2)(\-.7,-.2)(\-.6,-.2)^^A
+% \closepath
+% \fillpath
+% \moveto(\+.9,.1)^^A
+% \curveto(\+1.8,0)(\+2.3,.3)(\+2.1,.8)^^A
+% \curveto(\+2.6,.7)(\+3.3,-.1)(\+3,-.8)^^A
+% \curveto(\+2.7,-.3)(\+2,-.6)(\+2,-1.1)^^A
+% \curveto(\+2,-.6)(\+1.7,-.5)(\+1.5,-.8)^^A
+% \curveto(\+1.6,-.5)(\+1.3,-.3)(\+1.1,-.6)^^A
+% \curveto(\+1.1,-.4)(\+1,-.4)(\+.8,-.4)^^A
+% \closepath
+% \fillpath
+% \moveto(\+.8,-.1)^^A
+% \curveto(\+.85,.08)(\+.65,.13)(\+.6,-.05)^^A
+% \lineto(\+.3,0)^^A
+% \curveto(\+.35,.2)(\+.05,.3)(0,.1)^^A
+% \lineto(\-.85,0)^^A
+% \curveto(\-.75,.3)(\-.4,.7)(\+.25,1.1)^^A
+% \curveto(\+.2,.55)(\+.8,.45)(\+1,1)^^A
+% \curveto(\+1.1,.8)(\+1.2,.2)(\+1.05,0)^^A
+% \closepath
+% \fillpath
+% \moveto(\+.8,-.1)^^A
+% \curveto(\+.75,-.28)(\+.55,-.23)(\+.6,-.05)^^A
+% \lineto(\+.3,0)^^A
+% \curveto(\+.25,-.18)(\-.05,-.08)(0,.1)^^A
+% \lineto(\-.85,0)^^A
+% \curveto(\-.95,-.3)(\-.8,-.6)(\-1,-1)^^A
+% \curveto(\-.75,-.7)(\-.4,-.8)(\-.5,-1.1)^^A
+% \curveto(\-.2,-.8)(\+.2,-.82)(\+.3,-.8)^^A
+% \curveto(\+.85,-.69)(\+1.04,-.0133333)(\+1.05,0)^^A
+% \closepath
+% \fillpath
+% }
+%
+% \centering
+% \addtolength\leftskip {-2cm}
+% \addtolength\rightskip{-2cm}
+%
+% The asymmetric bat,
+% in the \texttt{normal}\ldots\\*[\bigskipamount]
+% \begin{picture}(6,4)(-3,-2)
+% \def\+{-}
+% \def\-{+}
+% \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}
+% \AsymmBat
+% \end{picture}\qquad
+% \begin{picture}(6,4)(-3,-2)
+% \def\+{+}
+% \def\-{-}
+% \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}
+% \AsymmBat
+% \end{picture}
+%
+% \bigskip\bigskip\bigskip
+%
+% \ldots and in the \texttt{bold} math version.\\*[\bigskipamount]
+% \begin{picture}(6,4)(-3,-2)
+% \def\+{-}
+% \def\-{+}
+% \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}
+% \BoldAsymmBat
+% \end{picture}\qquad
+% \begin{picture}(6,4)(-3,-2)
+% \def\+{+}
+% \def\-{-}
+% \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}
+% \BoldAsymmBat
+% \end{picture}
+%
+% \caption{Sketches of the asymmetric bats}
+% \label{fig:a-bats}
+% \end{figure}
+%
+% \begin{macro}{\@HwM@symmetric@bat@wing}
+% Subroutine that draws the wing of a symmetric, normal (that is, not bold)
+% bat. Argument~\#1 is either \texttt{-} or~\texttt{+}, depending on which
+% wing you want to draw.
+% \begin{macrocode}
+\newcommand*\@HwM@symmetric@bat@wing[1]{%
+ \moveto(#1.7,0)%
+ \curveto(#11.5,.1)(#12.2,.5)(#12,1)%
+ \curveto(#12.5,.5)(#12.9,0)(#12.9,-.5)%
+ \curveto(#12.8,0)(#12,-.5)(#12.25,-1)%
+ \curveto(#12,-.5)(#11.7,-.3)(#11.5,-.7)%
+ \curveto(#11.4,-.5)(#11.2,-.3)(#11,-.5)%
+ \curveto(#1.9,-.4)(#1.7,-.4)(#1.5,-.5)%
+ \closepath
+ \fillpath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@symmetric@bbat@wing}
+% Subroutine that draws the wing of a symmetric, bold bat (note the
+% additional~\texttt{b}). Argument~\#1 is either \texttt{-} or~\texttt{+},
+% depending on which wing you want to draw.
+% \begin{macrocode}
+\newcommand*\@HwM@symmetric@bbat@wing[1]{%
+ \moveto(#1.7,.1)%
+ \curveto(#11.5,.2)(#12.25,.6)(#12,1.1)%
+ \curveto(#12.6,.5)(#13,0)(#13,-.6)%
+ \curveto(#12.8,0)(#12,-.6)(#12.25,-1.1)%
+ \curveto(#12,-.6)(#11.7,-.4)(#11.5,-.8)%
+ \curveto(#11.4,-.6)(#11.2,-.4)(#11,-.6)%
+ \curveto(#1.9,-.5)(#1.7,-.5)(#1.5,-.5)%
+ \closepath
+ \fillpath
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@symmetric@bat}
+% Macro that draws the symmetric, normal (that is, not bold) bat. Argument:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@symmetric@bat[1]{%
+ \begin{@HwM@math@picture}{2}{-1}{}#1{6}{-3}%
+ \moveto(-.5,-.5)%
+ \curveto(-.4,-.6)(-.2,-.7)(-.2,-1)%
+ \curveto(-.1,-.7)(.1,-.7)(.2,-1)%
+ \curveto(.2,-.7)(.4,-.6)(.5,-.5)%
+ \closepath
+ \fillpath
+ \@HwM@symmetric@bat@wing-%
+ \@HwM@symmetric@bat@wing+%
+ \moveto(.5,0)%
+ \circlearc{.35}{0}{.15}{0}{180}%
+ \lineto(-.2,0)%
+ \circlearc{-.35}{0}{.15}{0}{180}%
+ \lineto(-.75,0)%
+ \curveto(-.75,.45)(-.7,.5)(-.5,1)%
+ \circlearc{0}{1}{.5}{180}{360}%
+ \curveto(.7,.5)(.75,.45)(.75,0)%
+ \closepath
+ \fillpath
+ \moveto(-.75,0)%
+ \circlearc{0}{0}{.75}{180}{360}%
+ \lineto(.5,0)%
+ \circlearc{.35}{0}{.15}{360}{180}%
+ \lineto(-.2,0)%
+ \circlearc{-.35}{0}{.15}{360}{180}%
+ \closepath
+ \fillpath
+ \end{@HwM@math@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@symmetric@bold@bat}
+% Macro that draws the symmetric, bold bat. Argument:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@symmetric@bold@bat[1]{%
+ \begin{@HwM@math@picture}{2}{-1}{}#1{6}{-3}%
+ \moveto(-.6,-.5)%
+ \curveto(-.5,-.6)(-.3,-.7)(-.3,-1.1)%
+ \curveto(-.1,-.7)(.1,-.7)(.3,-1.1)%
+ \curveto(.3,-.7)(.5,-.6)(.6,-.5)%
+ \closepath
+ \fillpath
+ \@HwM@symmetric@bbat@wing-%
+ \@HwM@symmetric@bbat@wing+%
+ \moveto(.5,0)%
+ \circlearc{.35}{0}{.15}{0}{180}%
+ \lineto(-.2,0)%
+ \circlearc{-.35}{0}{.15}{0}{180}%
+ \lineto(-.8,0)%
+ \curveto(-.8,.5)(-.7,.5)(-.55,1.1)%
+ \circlearc{0}{1.1}{.55}{180}{360}%
+ \curveto(.7,.5)(.8,.5)(.8,0)%
+ \closepath
+ \fillpath
+ \moveto(-.8,0)%
+ \circlearc{0}{0}{.8}{180}{360}%
+ \lineto(.5,0)%
+ \circlearc{.35}{0}{.15}{360}{180}%
+ \lineto(-.2,0)%
+ \circlearc{-.35}{0}{.15}{360}{180}%
+ \closepath
+ \fillpath
+ \end{@HwM@math@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Symmetric@Bat}
+% Macro that draws the symmetric bat, automatically choosing between the
+% normal and the bold version; because of this, it is directly a ``public''
+% macro. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% The first parameter is imposed by the interface toward other parts of the
+% code, even if is not used here (as it happened in several other similar
+% macros).
+% \begin{macrocode}
+\newcommand*\@HwM@Symmetric@Bat[2]{%
+ \@HwM@if@bold@math{%
+ \@HwM@symmetric@bold@bat #2%
+ }{%
+ \@HwM@symmetric@bat #2%
+ }%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@asymmetric@bat}
+% Macro that draws the asymmetric, normal (that is, not bold) bat. Argument:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@asymmetric@bat[1]{%
+ \begin{@HwM@math@picture}{2}{-1}{}#1{6}{-3}%
+ \moveto(\-.5,.2)%
+ \curveto(\-1.5,.3)(\-2.2,.5)(\-1.8,1)%
+ \curveto(\-2.5,.5)(\-2.9,0)(\-2.9,-.5)%
+ \curveto(\-2.7,0)(\-2,-.25)(\-2,-.8)%
+ \curveto(\-2,-.5)(\-1.6,-.25)(\-1.4,-.5)%
+ \curveto(\-1.4,-.2)(\-1.2,-.1)(\-1,-.3)%
+ \curveto(\-1,-.1)(\-.7,-.1)(\-.6,-.1)%
+ \closepath
+ \fillpath
+ \moveto(\+.9,0)
+ \curveto(\+2,-.1)(\+2.2,.5)(\+2,.7)
+ \curveto(\+2.5,.6)(\+3.2,0)(\+2.9,-.7)%
+ \curveto(\+2.6,-.2)(\+2,-.5)(\+2,-1)%
+ \curveto(\+2,-.5)(\+1.7,-.4)(\+1.5,-.7)%
+ \curveto(\+1.6,-.4)(\+1.3,-.2)(\+1.1,-.5)%
+ \curveto(\+1.1,-.3)(\+1,-.3)(\+.8,-.3)%
+ \closepath
+ \fillpath
+ \moveto(\+.8,-.1)%
+ \curveto(\+.85,.08)(\+.65,.13)(\+.6,-.05)%
+ \lineto(\+.3,0)%
+ \curveto(\+.35,.2)(\+.05,.3)(0,.1)%
+ \lineto(\-.8,0)%
+ \curveto(\-.7,.3)(\-.4,.7)(\+.25,1)%
+ \curveto(\+.2,.4)(\+.8,.3)(\+1,.9)%
+ \curveto(\+1.1,.7)(\+1.1,.2)(\+1,0)%
+ \closepath
+ \fillpath
+ \moveto(\+.8,-.1)%
+ \curveto(\+.75,-.28)(\+.55,-.23)(\+.6,-.05)%
+ \lineto(\+.3,0)%
+ \curveto(\+.25,-.18)(\-.05,-.08)(0,.1)%
+ \lineto(\-.8,0)%
+ \curveto(\-.9,-.3)(\-.8,-.6)(\-1,-.9)%
+ \curveto(\-.8,-.6)(\-.4,-.7)(\-.6,-1)%
+ \curveto(\-.2,-.8)(\+.2,-.82)(\+.3,-.8)%
+ \curveto(\+.85,-.69)(\+.99,-.02)(\+1,0)%
+ \closepath
+ \fillpath
+ \end{@HwM@math@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@asymmetric@bold@bat}
+% Macro that draws the asymmetric, bold bat. Argument:
+% \begin{paramlist}
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@asymmetric@bold@bat[1]{%
+ \begin{@HwM@math@picture}{2}{-1}{}#1{6}{-3}%
+ \moveto(\-.5,.3)%
+ \curveto(\-1.5,.4)(\-2.2,.6)(\-1.9,1.1)%
+ \curveto(\-2.6,.6)(\-3,0)(\-3,-.6)%
+ \curveto(\-2.6,-.1)(\-2,-.4)(\-2,-.9)%
+ \curveto(\-2,-.6)(\-1.6,-.35)(\-1.4,-.6)%
+ \curveto(\-1.4,-.3)(\-1.2,-.2)(\-1,-.4)%
+ \curveto(\-1,-.2)(\-.7,-.2)(\-.6,-.2)%
+ \closepath
+ \fillpath
+ \moveto(\+.9,.1)
+ \curveto(\+1.8,0)(\+2.3,.3)(\+2.1,.8)%
+ \curveto(\+2.6,.7)(\+3.3,-.1)(\+3,-.8)%
+ \curveto(\+2.7,-.3)(\+2,-.6)(\+2,-1.1)%
+ \curveto(\+2,-.6)(\+1.7,-.5)(\+1.5,-.8)%
+ \curveto(\+1.6,-.5)(\+1.3,-.3)(\+1.1,-.6)%
+ \curveto(\+1.1,-.4)(\+1,-.4)(\+.8,-.4)%
+ \closepath
+ \fillpath
+ \moveto(\+.8,-.1)%
+ \curveto(\+.85,.08)(\+.65,.13)(\+.6,-.05)%
+ \lineto(\+.3,0)%
+ \curveto(\+.35,.2)(\+.05,.3)(0,.1)%
+ \lineto(\-.85,0)%
+ \curveto(\-.75,.3)(\-.4,.7)(\+.25,1.1)%
+ \curveto(\+.2,.55)(\+.8,.45)(\+1,1)%
+ \curveto(\+1.1,.8)(\+1.2,.2)(\+1.05,0)%
+ \closepath
+ \fillpath
+ \moveto(\+.8,-.1)%
+ \curveto(\+.75,-.28)(\+.55,-.23)(\+.6,-.05)%
+ \lineto(\+.3,0)%
+ \curveto(\+.25,-.18)(\-.05,-.08)(0,.1)%
+ \lineto(\-.85,0)%
+ \curveto(\-.95,-.3)(\-.8,-.6)(\-1,-1)%
+ \curveto(\-.75,-.7)(\-.4,-.8)(\-.5,-1.1)%
+ \curveto(\-.2,-.8)(\+.2,-.82)(\+.3,-.8)%
+ \curveto(\+.85,-.69)(\+1.04,-.0133333)(\+1.05,0)%
+ \closepath
+ \fillpath
+ \end{@HwM@math@picture}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@Asymmetric@Bat}
+% Macro that draws the asymmetric bat, automatically choosing between the
+% normal and the bold version; because of this, it is directly a ``public''
+% macro. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% This should be the last time we have to repeat the usual remark about the
+% first parameter: although it is not used in this macro, it is imposed by
+% the interface toward other parts of the code, which is shared also by a few
+% macros that, instead, require the information it conveys.
+% \begin{macrocode}
+\newcommand*\@HwM@Asymmetric@Bat[2]{%
+ \@HwM@if@bold@math{%
+ \@HwM@asymmetric@bold@bat #2%
+ }{%
+ \@HwM@asymmetric@bat #2%
+ }%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{New brooms, old pitchforks}
+%
+% As we have already remarked in the first part, more precisely in
+% Subsection~\ref{ssS:Witches}, the look of brooms, as they were implemented
+% by the first release of this package, had already been
+% \href{https://tex.stackexchange.com/questions/336768/seasonal-challenge-contributions-from-texing-dead-welcome#comment829686_337719}{politely
+% questioned}: the problem was that, in certain commands, the brush was
+% rendered as an "\in" or~"\ni" character ($\in$/$\ni$), making the supposed
+% broom look more like a pitchfork. The same commands now represent the
+% brush with a composite character obtained by overprinting a $<$ or~$>$
+% character to a~$-$; however, the old representation is retained too, using
+% different command names. The following macros define both the old-style
+% pitchforks and the new ``composite'' brushes.
+%
+% \begin{macro}{\@HwM@oooalign}
+% This macro overprints two or more characters, taking math style into due
+% account. It is my personal version of "\ooalign". Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\textstyle");\\
+% \param
+% the symbols to be printed over oneanother, separated by "\cr".
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@oooalign[2]{%
+ \leavevmode
+ \vbox{%
+ \baselineskip\z@skip
+% \end{macrocode}
+% The following line is just for elegance, since "\lineskip" will never be
+% used\ldots
+% \begin{macrocode}
+ \lineskip\z@skip
+% \end{macrocode}
+% \ldots given the setting of "\lineskiplimit".
+% \begin{macrocode}
+ \lineskiplimit -\maxdimen
+ \m@th
+ \ialign{\hfil$#1##$\hfil\crcr #2\crcr}%
+ }%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@overprint@rel}
+% This macro builds a composite relation symbol out of the two characters
+% specified in the arguments.
+% \begin{macrocode}
+\newcommand*\@HwM@overprint@rel[2]{%
+ \mathrel{\mathpalette \@HwM@oooalign {#1\cr#2}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% The \packlass{\amsmath} package secures away, under the name "\std@minus",
+% the original "\mathcode" of the \texttt{-}~character; it does so because
+% this "\mathcode" is redefined when typesetting operator names
+% (see~\cite{bib:diffs-m}, near the end of the ``Changes in amsmath~2.0
+% [November 1999]''), and this would cause an extensible arrow, that happened
+% to be used inside an operator name, as in
+% \begin{verbatim}\DeclareMathOperator{\test}{\underleftrightarrow{test}}\end{verbatim}
+% to come out wrong. The saved "\mathcode" is used later in the "\relbar"
+% macro. Since we use are using "\relbar" for our brooms too, for some while
+% we've been concerned that other symbols we are going to employ could ``get
+% out of synch'', as it were, with what "\relbar" would yield. This had
+% initially led us to adopt the following, ``paranoid'' approach:
+% \begin{verbatim}\def\do#1#2{\@ifdefinable#1{\mathchardef#1=\mathcode`#2\relax}}
+%\do \@HwM@std@greater >
+%\do \@HwM@std@less <
+%\def\do#1#2\@ifdefinable#1{\let #1=#2}
+%\do \@HwM@std@in \in
+%\do \@HwM@std@ni \ni
+%\AtBeginDocument{%
+% \mathchardef \@HwM@std@greater \mathcode`>\relax
+% \mathchardef \@HwM@std@less \mathcode`<\relax
+% \let \@HwM@std@in = \in
+% \let \@HwM@std@ni = \ni
+%}
+%\newcommand*\@HwM@rightbroomtail{%
+% \@HwM@overprint@rel \std@minus \@HwM@std@greater
+%}
+%\newcommand*\@HwM@leftbroomtail{%
+% \@HwM@overprint@rel \std@minus \@HwM@std@less
+%}
+%\newcommand*\@HwM@rightpforktail{\mathrel\@HwM@std@ni}
+%\newcommand*\@HwM@leftpforktail {\mathrel\@HwM@std@in}\end{verbatim}
+% Note that the definition of "\in" and~"\ni" was secured away too (and saved
+% again at "\begin{document}"!\@), and not even I~can tell what was the
+% reasoning behind that: being \TeXtok{mathchardef token}'s by their own,
+% "\in" and~"\ni" needn't be saved as such; admittedly, there had been no
+% reasoning at all! The redundant "\mathrel" in the definition of
+% "\@HwM@rightpforktail" and "\@HwM@leftpforktail" deserves special mention
+% as well; but we find the same redundancy in the definition of "\Relbar",
+% not only in \packlass{\amsmath}, but also back in Knuth's coding of the
+% \texttt{plain} format.
+%
+% Later on, paranoia was lowered to what could even be deemed a sensible
+% level; indeed, storing away the "\mathcode" of~\texttt{<}/\texttt{>} is
+% closely similar to what the \packlass{\amsmath} package does when it
+% defines "\std@equal".
+% \begin{verbatim}\def\do#1#2{\@ifdefinable#1{\mathchardef#1=\mathcode`#2\relax}}
+%\do \@HwM@std@greater >
+%\do \@HwM@std@less <
+%\AtBeginDocument{%
+% \mathchardef \@HwM@std@greater \mathcode`>\relax
+% \mathchardef \@HwM@std@less \mathcode`<\relax
+%}
+%\newcommand*\@HwM@rightbroomtail{%
+% \@HwM@overprint@rel \std@minus \@HwM@std@greater
+%}
+%\newcommand*\@HwM@leftbroomtail{%
+% \@HwM@overprint@rel \std@minus \@HwM@std@less
+%}
+%\newcommand*\@HwM@rightpforktail{\mathrel\ni}
+%\newcommand*\@HwM@leftpforktail {\mathrel\in}\end{verbatim}
+% However, this code retains the fundamental drawback that affected the
+% previous version as well: it will break down with engines that use Unicode
+% math. Of course, it would be easy to cater for this too, but the point is
+% that\ldots\ well, there's no point in all this "\mathcode" securement in
+% the first place: OK\@, it is necessary to provide it for the~\texttt{-}
+% character, which can denote two different symbols (minus and hyphen), taken
+% from two different fonts, but neither for \texttt{<} or~\texttt{>}, nor,
+% for that matter, for~\texttt{=}. So, in the end we decided simply to keep
+% the symbolic names for the ``broom tail'' symbols, so that they serve as
+% hooks, should we ever need to take a different course of action in the
+% future, but to specify \texttt{<} and~\texttt{>} as literals, at least for
+% now.
+%
+% \begin{macro}{\@HwM@rightbroomtail}
+% The representation of the brush in the ``new'' brooms; version for brooms
+% that point to the right.
+% \begin{macrocode}
+\newcommand*\@HwM@rightbroomtail{\@HwM@overprint@rel \std@minus >}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@leftbroomtail}
+% As above, but for brooms that point to the left.
+% \begin{macrocode}
+\newcommand*\@HwM@leftbroomtail {\@HwM@overprint@rel \std@minus <}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@rightpforktail}
+% Similar hook, but for pitchforks, pointing to the right.
+% \begin{macrocode}
+\newcommand*\@HwM@rightpforktail{\mathrel\ni}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@leftpforktail}
+% For pitchforks pointing to the left.
+% \begin{macrocode}
+\newcommand*\@HwM@leftpforktail {\mathrel\in}
+% \end{macrocode}
+% \end{macro}
+%
+% Note again that, in the last two macros, we retained the redundant
+% "\mathrel", exactly as Knuth and the authors of \packlass{\amsmath} did in
+% the definition of "\Relbar": indeed, in order for "\joinrel" to work
+% properly, it is essential that the symbols it acts on behave as relations,
+% while, on the other hand, as remote as it might seem, there is always the
+% possibility that the final user has redefined the r\^{o}le of "\in"/"ni".
+% (Or, at least, this the tale I~recount to myself\ldots)
+%
+% For the above discussion about "\std@minus", I~have to thank again the
+% people at \href{https://tex.stackexchange.com/}{\TeXSXAbbrev}, who provided
+% me with the necessary insight into the matter: see~\cite{bib:std}.
+%
+% \subsubsection{Helper macros for the extensible symbols}
+% \label{sS:ExtensHelper}
+%
+% This subsection contains some utility macros that help typeset certain
+% extensible components, like broomsticks, swishes of ghosts, and so on.
+% Such components are implemented by means of the "\leaders" primitive, or of
+% a variant thereof.
+%
+% \begin{macro}{\@HwM@arrowfill@skip}
+% Instead of relying on temporaries, we reserve a "\skip" register
+% specifically devoted to holding the skip for the "\leaders".
+% \begin{macrocode}
+\newlength\@HwM@arrowfill@skip
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@auto@font@selector}
+% Suppose you have \meta{something} (\eg 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 selector as the one that was
+% originally present, and \meta{font selector} is the correct font selector
+% that is associated with it (namely, "\textfont" for "\displaystyle" and
+% "\textstyle", "\scriptfont" for "\scriptstyle", and "\scriptscriptfont" for
+% "\scriptscriptstyle"). For example,
+% \begin{flushleft}
+% "\@HwM@auto@font@selector{"\meta{something}"}\displaystyle"
+% \end{flushleft}
+% is transformed into
+% \begin{flushleft}
+% \meta{something}"\displaystyle\textfont"
+% \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).
+% In version~0.01 of this package, this macro was implemented as shown here:
+% \begin{verbatim}\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{verbatim}
+% But in this version, the multiple-choice conditional has been simplified as
+% follows.
+% \textbf{Beware:} this is still 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\scriptscriptstyle #2%
+ \scriptscriptfont
+ \else \ifx\scriptstyle #2%
+ \scriptfont
+ \else
+ \textfont
+ \fi\fi
+ }%
+ \expandafter \@tempa \expandafter #2\@tempb
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@extended@arrowfill@}
+% This macro is loosely similar to the "\arrowfill@" macro found in the
+% \packlass{\amsmath} package, though its functionality is extended so as to
+% satisfy our needs. Basically, it invokes a caller-supplied (pseudo-)macro
+% that typeset the "\leaders", passing to it the appropriate value for
+% "\@HwM@arrowfill@skip". Arguments:
+% \begin{paramlist}
+% \param
+% the "\leaders" (pseudo-)macro (its arguments are specified below);\\
+% \param
+% the minimal width, expressed as a multiple of 18~math units.
+% \end{paramlist}
+% Arguments of the caller-supplied (pseudo-)macro:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\displaystyle");\\
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@extended@arrowfill@[2]{%
+ \@HwM@auto@font@selector
+ {\@HwM@stylefont@arrowfill{#1}{#2}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@stylefont@arrowfill}
+% This is, in a sense, the ``internal'' version of the above macro, that is,
+% the version that ought to be called \emph{after} the process of argument
+% doubling implemented by "\@HwM@auto@font@selector" has taken place (see the
+% description of that macro for details). Note that the name of this macro
+% does \emph{not} end in an~\texttt{@}. Arguments:
+% \begin{paramlist}
+% \param
+% the "\leaders" (pseudo-)macro (having the same 2~arguments as above);\\
+% \param
+% the minimal width, expressed as a multiple of 18~math units;\\
+% \param
+% style selector (\eg "\displaystyle");\\
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@stylefont@arrowfill[4]{%
+ $\m@th
+ \thickmuskip 0mu%
+ \medmuskip \thickmuskip
+ \thinmuskip \thickmuskip
+ \setlength\@HwM@arrowfill@skip
+ {#2\fontdimen 6 #4\tw@ \@plus \@ne fill}%
+ #3%
+ #1#3#4%
+ $%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@enriched@arrowfill@}
+% This macro provides an ``enriched'' version of the "\arrowfill@" macro,
+% that invokes two additional macros, supplied by the caller, one before and
+% one after "\cleaders"; these macros can insert additional stretchable
+% material. In practice, this is used, below, to add the black cat on the
+% broomstick. Note that, here, the ``"\leaders" pseudo-macro'' is
+% ``"\HwM@arrowfill@cleaders{#1}{#2}{#3}{#4}{#5}"''.
+%
+% The arguments for this macro are as follows:
+% \begin{tightitemize}
+% \item
+% \#1, \#2, and~\#3 are the three characters that would be used by
+% "\arrowfill@" for the "\cleaders" (resp.: left, repeatable, right);
+% \item
+% \#4 and~\#5 are the two additional macros (resp.: left of "\cleaders",
+% right of "\cleaders");
+% \item
+% those argument must be followed, in the calling code, by the argument
+% that holds the minimal size of the extensible symbol.
+% \end{tightitemize}
+% The arguments of the two ``additional macros'' are as follows:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\displaystyle");\\
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@enriched@arrowfill@[5]{%
+ \@HwM@extended@arrowfill@
+ {\HwM@arrowfill@cleaders{#1}{#2}{#3}{#4}{#5}}%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\HwM@arrowfill@cleaders}
+% The arguments for this macro are as follows:
+% \begin{tightitemize}
+% \item
+% \#1, \#2, and~\#3 are the three characters, as above;
+% \item
+% \#4 and~\#5 are the two additional macros, as above;
+% \item
+% \( \mbox{\#6} \leftarrow \mbox{style sel.} \)
+% (\eg "\displaystyle"),
+% \( \mbox{\#7} \leftarrow \mbox{font sel.} \)
+% (\eg "\textfont").
+% \end{tightitemize}
+% \begin{macrocode}
+\newcommand*\HwM@arrowfill@cleaders[7]{%
+ #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%
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Macros for extensible symbols (brooms, ghosts,~\ldots)}
+%
+% This subsection defines the actual macros that typeset the extensible
+% broomsticks, swishes, etc., building on the top of the macros presented in
+% Subsection~\ref{sS:ExtensHelper}. Extensible broomsticks come first.
+%
+% \begin{macro}{\@HwM@rightbroomfill@Wwac@}
+% This macro should be thought of as an analog of \packlass{\amsmath}'s
+% "\rightarrowfill@": it takes no arguments and yields an extensible broom
+% complete with witch and, if appropriate, cat, both facing toward the right.
+% For this macro only, we choose to include extensive comments, that
+% exemplify how the macros defined in the
+% \hyperref[sS:ExtensHelper]{preceding subsection} can be utilized.
+% \begin{macrocode}
+\newcommand*\@HwM@rightbroomfill@Wwac@{%
+% \end{macrocode}
+% Set up the right-facing direction:
+% \begin{macrocode}
+ \@HwM@set@right@dir
+% \end{macrocode}
+% Have "\@HwM@enriched@arrowfill@" (assemble and) supply the extensible
+% broom. Recall that the first three arguments are the characters it is
+% built from:
+% \begin{macrocode}
+ \@HwM@enriched@arrowfill@ \@HwM@rightbroomtail\relbar\relbar
+% \end{macrocode}
+% The first additional macro (left of "\cleaders") does nothing,
+% yet it must gobble two arguments:
+% \begin{macrocode}
+ \@gobbletwo
+% \end{macrocode}
+% The second additional macro adds the witch, and possibly the cat, to the
+% right of the "\cleaders", and is defined below:
+% \begin{macrocode}
+ \@HwM@right@add@witch@cat
+% \end{macrocode}
+% The minimal size of the extensible broom (1~chunk of 18\,mu =~18\,mu):
+% \begin{macrocode}
+ \@ne
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@rightpitchfill@Wwac@}
+% Like "\@HwM@rightbroomfill@Wwac@", but yields an extensible pitchfork.
+% \begin{macrocode}
+\newcommand*\@HwM@rightpitchfill@Wwac@{%
+ \@HwM@set@right@dir
+ \@HwM@enriched@arrowfill@ \@HwM@rightpforktail\relbar\relbar
+ \@gobbletwo
+ \@HwM@right@add@witch@cat
+ \@ne
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@right@add@witch@cat}
+% Adds the witch and possibly the cat. Arguments:
+% \begin{paramlist}
+% \param
+% style selector (\eg "\displaystyle"), ignored;\\
+% \param
+% font selector (\eg "\textfont").
+% \end{paramlist}
+% \begin{macrocode}
+\newcommand*\@HwM@right@add@witch@cat[2]{%
+% \end{macrocode}
+% First backspace by half of the width of the extensible symbol\ldots
+% \begin{macrocode}
+ \hskip -\glueexpr \@HwM@arrowfill@skip/\tw@ \relax
+% \end{macrocode}
+% \ldots then typeset the witch.
+% \begin{macrocode}
+ \@HwM@Small@Witch@Wo@Broom #2%
+% \end{macrocode}
+% If the cat has also been requested\ldots
+% \begin{macrocode}
+ \if@HwM@cat@
+% \end{macrocode}
+% \ldots then move forward by $1/4$~of the width\ldots
+% \begin{macrocode}
+ \hskip \glueexpr \@HwM@arrowfill@skip/4 \relax
+% \end{macrocode}
+% \ldots typeset the cat\ldots
+% \begin{macrocode}
+ \@HwM@Small@Cat@On@Hori@Broom #2%
+% \end{macrocode}
+% \ldots then move forward by another $1/4$~of the width.
+% \begin{macrocode}
+ \hskip \glueexpr \@HwM@arrowfill@skip/4 \relax
+% \end{macrocode}
+% Otherwise, just move forward by $1/2$~of the width, thus canceling the
+% previous backspace.
+% \begin{macrocode}
+ \else
+ \hskip \glueexpr \@HwM@arrowfill@skip/\tw@ \relax
+ \fi
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@leftbroomfill@Wwac@}
+% Like "\@HwM@rightbroomfill@Wwac@", but facing to the left.
+% \begin{macrocode}
+\newcommand*\@HwM@leftbroomfill@Wwac@{%
+ \@HwM@set@left@dir
+ \@HwM@enriched@arrowfill@ \relbar\relbar\@HwM@leftbroomtail
+ \@HwM@left@add@witch@cat
+ \@gobbletwo
+ \@ne
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@leftpitchfill@Wwac@}
+% Like "\@HwM@rightpitchfill@Wwac@", but facing to the left.
+% \begin{macrocode}
+\newcommand*\@HwM@leftpitchfill@Wwac@{%
+ \@HwM@set@left@dir
+ \@HwM@enriched@arrowfill@ \relbar\relbar\@HwM@leftpforktail
+ \@HwM@left@add@witch@cat
+ \@gobbletwo
+ \@ne
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@HwM@left@add@witch@cat}
+% Similar to "\@HwM@right@add@witch@cat".
+% \begin{macrocode}
+\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
+}
+% \end{macrocode}
+% \end{macro}
+%
+% Next, we take care of the ``swishes'' that accompany ghosts and fluttering
+% bats. Probably, here, we should try harder to factor out common code.
+%
+% \begin{macro}{\@HwM@init@swish@dimens}
+% Subroutine; \#1~is a font selector (\eg "\textfont").
+% \begin{macrocode}
+\newcommand*\@HwM@init@swish@dimens[1]{%
+ \dimen4 \glueexpr \fontdimen 22 #1\tw@ *\tw@/\thr@@
+ \dimen6 .\@HwM@if@bold@math{333333}{25}\@HwM@thickness@units@for #1%
+ \dimen@ \dimen4
+ \@HwM@calc@swish@thickness
+}
+% \end{macrocode}
+% \end{macro}
+%
+% \textbf{Uncommented code} starts here.
+% \begin{macrocode}
+\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@swish[3]{%
+ % #1 := swishing subform. (e.g., "\mkern 1.5mu\relax \mathrightbat")
+ % #2 := style selector (e.g., "\displaystyle")
+ % #3 := font selector (e.g., "\textfont")
+ \@HwM@init@swish@dimens #3%
+ \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
+ #1%
+}
+\newcommand*\@HwM@left@swish[3]{%
+ % #1 := swishing subformula (e.g., "\mathleftbat \mkern 1.5mu\relax")
+ % #2 := style selector (e.g., "\displaystyle")
+ % #3 := font selector (e.g., "\textfont")
+ #1%
+ \@HwM@init@swish@dimens #3%
+ \@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@swish \mathrightghost}{.5}%
+}
+\newcommand*\@HwM@leftghostfill@{%
+ \@HwM@extended@arrowfill@ {\@HwM@left@swish \mathleftghost}{.5}%
+}
+\newcommand*\@HwM@rightbatfill@{%
+ \@HwM@extended@arrowfill@
+ {\@HwM@right@swish{\mkern 1.5mu\relax \mathrightbat}}{.5}%
+}
+\newcommand*\@HwM@leftbatfill@{%
+ \@HwM@extended@arrowfill@
+ {\@HwM@left@swish{\mathleftbat \mkern 1.5mu\relax}}{.5}%
+}
+
+\newcommand*\@HwM@rightbroomfill@{%
+ \arrowfill@ \@HwM@rightbroomtail\relbar\relbar
+}
+\newcommand*\@HwM@leftbroomfill@{%
+ \arrowfill@ \relbar\relbar\@HwM@leftbroomtail
+}
+\newcommand*\@HwM@rightpitchfill@{%
+ \arrowfill@ \@HwM@rightpforktail\relbar\relbar
+}
+\newcommand*\@HwM@leftpitchfill@{%
+ \arrowfill@ \relbar\relbar\@HwM@leftpforktail
+}
+
+\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}%
+}
+
+\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}%
+}
+
+\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@Binop@Pumpkin
+}
+\newcommand*\bigpumpkin{%
+ \DOTSB
+ \@HwM@general@large@operator \@HwM@Large@Pumpkin \@HwM@Small@Pumpkin
+}
+\@ifdefinable\greatpumpkin{\let\greatpumpkin=\bigpumpkin}
+
+\newcommand*\skull{%
+ \DOTSB
+ \@HwM@general@binary@operation \@HwM@Binop@Skull
+}
+\newcommand*\bigskull{%
+ \DOTSB
+ \@HwM@general@large@operator \@HwM@Large@Skull \@HwM@Small@Skull
+}
+
+\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
+}
+
+\newcommand*\mathbat{%
+ \@HwM@general@ordinary@symbol \@HwM@Symmetric@Bat
+}
+\newcommand*\mathrightbat{\@HwM@set@right@dir \@HwM@mathbat}
+\newcommand*\mathleftbat {\@HwM@set@left@dir \@HwM@mathbat}
+\newcommand*\@HwM@mathbat{%
+ \@HwM@general@ordinary@symbol \@HwM@Asymmetric@Bat
+}
+
+\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*\overrightwitchonpitchfork{%
+ \@HwM@general@ou@w@cat
+ {\@HwM@dblstyle@overarrow@ \@HwM@rightpitchfill@Wwac@}%
+}
+\newcommand*\overleftwitchonpitchfork{%
+ \@HwM@general@ou@w@cat
+ {\@HwM@dblstyle@overarrow@ \@HwM@leftpitchfill@Wwac@}%
+}
+\newcommand*\overrightswishingghost{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@rightghostfill@}%
+}
+\newcommand*\overleftswishingghost{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@leftghostfill@}%
+}
+\newcommand*\overrightflutteringbat{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@rightbatfill@}%
+}
+\newcommand*\overleftflutteringbat{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@leftbatfill@}%
+}
+\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*\underrightwitchonpitchfork{%
+ \@HwM@general@ou@w@cat
+ {\@HwM@dblstyle@underarrow@ \@HwM@rightpitchfill@Wwac@}%
+}
+\newcommand*\underleftwitchonpitchfork{%
+ \@HwM@general@ou@w@cat
+ {\@HwM@dblstyle@underarrow@ \@HwM@leftpitchfill@Wwac@}%
+}
+\newcommand*\underrightswishingghost{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@rightghostfill@}%
+}
+\newcommand*\underleftswishingghost{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@leftghostfill@}%
+}
+\newcommand*\underrightflutteringbat{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@rightbatfill@}%
+}
+\newcommand*\underleftflutteringbat{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@leftbatfill@}%
+}
+\newcommand*\overrightbroom{%
+ \mathpalette{\overarrow@ \@HwM@rightbroomfill@}%
+}
+\newcommand*\overleftbroom{%
+ \mathpalette{\overarrow@ \@HwM@leftbroomfill@}%
+}
+\newcommand*\overrightpitchfork{%
+ \mathpalette{\overarrow@ \@HwM@rightpitchfill@}%
+}
+\newcommand*\overleftpitchfork{%
+ \mathpalette{\overarrow@ \@HwM@leftpitchfill@}%
+}
+\newcommand*\underrightbroom{%
+ \mathpalette{\underarrow@ \@HwM@rightbroomfill@}%
+}
+\newcommand*\underleftbroom{%
+ \mathpalette{\underarrow@ \@HwM@leftbroomfill@}%
+}
+\newcommand*\underrightpitchfork{%
+ \mathpalette{\underarrow@ \@HwM@rightpitchfill@}%
+}
+\newcommand*\underleftpitchfork{%
+ \mathpalette{\underarrow@ \@HwM@leftpitchfill@}%
+}
+\newcommand*\overscriptrightbroom{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@rightbroomfill@}%
+}
+\newcommand*\overscriptleftbroom{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@leftbroomfill@}%
+}
+\newcommand*\overscriptrightpitchfork{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@rightpitchfill@}%
+}
+\newcommand*\overscriptleftpitchfork{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@overarrow@ \@HwM@leftpitchfill@}%
+}
+\newcommand*\underscriptrightbroom{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@rightbroomfill@}%
+}
+\newcommand*\underscriptleftbroom{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@leftbroomfill@}%
+}
+\newcommand*\underscriptrightpitchfork{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@rightpitchfill@}%
+}
+\newcommand*\underscriptleftpitchfork{%
+ \@HwM@dblstyle@mathpalette
+ {\@HwM@dblstyle@underarrow@ \@HwM@leftpitchfill@}%
+}
+\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@}%
+}
+
+\newcommand*\@HwM@make@arrowfill@like[3]{%
+ % #1 := base symbol, which expects as its own arguments
+ % - #1, a style selector (e.g., "\scriptstyle")
+ % - #2, a font selector (e.g., "\scriptfont")
+ % #2 := centering method, either "\hfil" or "\hidewidth"
+ % #3 := style selector (e.g., "\scriptstyle")
+ #2%
+ \@HwM@auto@font@selector{#1}#3% braces around #1 are for robustness
+ #2%
+}
+\newcommand*\@HwM@over@under@bat[2]{%
+ % #1 := "\@HwM@dblstyle@overarrow@" | "\@HwM@dblstyle@underarrow@"
+ % #2 := "\hfil" | "\hidewidth"
+ \@HwM@dblstyle@mathpalette{%
+ #1{%
+ \@HwM@make@arrowfill@like \@HwM@Symmetric@Bat #2%
+ }%
+ }%
+}
+\newcommand*\overbat{%
+ \@ifstar{%
+ \@HwM@over@under@bat \@HwM@dblstyle@overarrow@ \hfil
+ }{%
+ \@HwM@over@under@bat \@HwM@dblstyle@overarrow@ \hidewidth
+ }%
+}
+\newcommand*\underbat{%
+ \@ifstar{%
+ \@HwM@over@under@bat \@HwM@dblstyle@underarrow@ \hfil
+ }{%
+ \@HwM@over@under@bat \@HwM@dblstyle@underarrow@ \hidewidth
+ }%
+}
+
+\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*\xrightwitchonpitchfork{%
+ \@HwM@ext@arrow@w@cat 9395\@HwM@rightpitchfill@Wwac@
+}
+\newcommand*\xleftwitchonpitchfork{%
+ \@HwM@ext@arrow@w@cat 3959\@HwM@leftpitchfill@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}%
+}
+\newcommand*\xrightflutteringbat[2][]{%
+ \ext@arrow 0055\@HwM@rightbatfill@{#1}{#2}%
+}
+\newcommand*\xleftflutteringbat[2][]{%
+ \ext@arrow 0055\@HwM@leftbatfill@{#1}{#2}%
+}
+\newcommand*\xrightbroom{%
+ \@HwM@ext@arrow@w@cat 9395\@HwM@rightbroomfill@
+}
+\newcommand*\xleftbroom{%
+ \@HwM@ext@arrow@w@cat 3959\@HwM@leftbroomfill@
+}
+\newcommand*\xrightpitchfork{%
+ \@HwM@ext@arrow@w@cat 9395\@HwM@rightpitchfill@
+}
+\newcommand*\xleftpitchfork{%
+ \@HwM@ext@arrow@w@cat 3959\@HwM@leftpitchfill@
+}
+
+\newcommand*\@HwM@tighter@joinrel{%
+ \mathrel{\mkern-6.5mu}%
+}
+\newcommand*\rightbroom{%
+ \DOTSB
+ \protect\@HwM@rightbroomtail
+ \protect\@HwM@tighter@joinrel
+ \protect\relbar
+ \protect\@HwM@tighter@joinrel
+ \protect\relbar
+}
+\newcommand*\leftbroom{%
+ \DOTSB
+ \protect\relbar
+ \protect\@HwM@tighter@joinrel
+ \protect\relbar
+ \protect\@HwM@tighter@joinrel
+ \protect\@HwM@leftbroomtail
+}
+\newcommand*\hmrightpitchfork{%
+ \DOTSB
+ \protect\@HwM@rightpforktail
+ \protect\@HwM@tighter@joinrel
+ \protect\relbar
+ \protect\@HwM@tighter@joinrel
+ \protect\relbar
+}
+\newcommand*\hmleftpitchfork{%
+ \DOTSB
+ \protect\relbar
+ \protect\@HwM@tighter@joinrel
+ \protect\relbar
+ \protect\@HwM@tighter@joinrel
+ \protect\@HwM@leftpforktail
+}
+
+\let \do = \noexpand
+% \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
+%
diff --git a/macros/latex/contrib/halloweenmath/halloweenmath.ins b/macros/latex/contrib/halloweenmath/halloweenmath.ins
new file mode 100644
index 0000000000..6a40a55226
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/halloweenmath.ins
@@ -0,0 +1,174 @@
+%
+% This is file `halloweenmath.ins'.
+%
+% This file is part of a work named "halloweenmath package".
+%
+% Copyright (C) 2017 by Gustavo MEZZETTI.
+%
+% The 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
+% 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.
+%
+% April 25, 2017 (vers. 0.10a)
+%
+\input docstrip
+
+\def\filename{halloweenmath.dtx}
+
+\newif\ifWritingToDirectoryOfTDS
+\WritingToDirectoryOfTDSfalse
+
+\edef\WriteToDir{\WriteToDir}
+\def\TryToUseMyDir{%
+ \usedir{tex/latex/halloweenmath}
+ \ifx \destdir\WriteToDir \else
+ \WritingToDirectoryOfTDStrue
+ \fi
+}
+\def\Y{Y}
+
+
+
+\Msg{----------------------------------------------------------------}
+\Msg{}
+\Msg{Unpacking the halloweenmath package.}
+\Msg{}
+\Msg{Please note: \space I will now try to install the generated files into}
+\Msg{their own TeX directory, using the \string\usedir\space facility of DocStrip;}
+\Msg{if that fails, they will be just saved in the current directory.}
+\Msg{In this case, in order to finish the installation, you will have}
+\Msg{to move them into a directory where LaTeX can find them: see the}
+\Msg{documentation specific to your TeX implementation to learn where}
+\Msg{such directories are located on your system.}
+\Msg{}
+
+\catcode`\@ = 11
+
+\ifx \usedir\alt@usedir
+
+\Msg{On your system, the name of the installation directory should be}
+\Msg{}
+\Msg{\space\space\space\space\showdirectory{tex/latex/halloweenmath}}
+\Msg{}
+\Msg{Please make sure that the above directory exists on your system,}
+\Msg{and that you have permission to create or overwrite files in it;}
+\Msg{if so, you may choose to put the generated files directly there.}
+\Msg{}
+\Msg{----------------------------------------------------------------}
+\Msg{}
+\Msg{Put files directly in suggested directory}
+\Msg{\space\space\space\space\showdirectory{tex/latex/halloweenmath}}
+\Ask\answer{or not? [y/n]}
+
+\ifx \answer\yes
+ \TryToUseMyDir
+\else \ifx \answer\y
+ \TryToUseMyDir
+\else \ifx \answer\Y
+ \TryToUseMyDir
+\fi \fi \fi
+
+\else % of \ifx \usedir\alt@usedir
+
+\Msg{It seems that the configuration of your system does not allow us}
+\Msg{to use the \string\usedir\space facility: writing files to current directory.}
+
+\fi % of \ifx \usedir\alt@usedir
+
+\catcode`\@ = 12
+
+\Msg{}
+
+\ifWritingToDirectoryOfTDS
+
+\Msg{Trying to install files directly in the proposed directory.}
+\Msg{}
+
+\else
+
+\Msg{Either you chose NOT to install files in the proposed directory,}
+\Msg{or, despite your choice, your system is not configured to permit}
+\Msg{you to do so. \space Therefore all files will be placed in the current}
+\Msg{directory and you will have to move them to a suitable directory}
+\Msg{by hand. \space At the end of this run, you will be presented with the}
+\Msg{complete list of the files you need to move.}
+\Msg{}
+\Ask\answer{Press \space <return> \space to continue
+ (your \string\answer\space will be ignored).}
+
+\fi
+
+\preamble
+
+This is a generated file.
+It is part of a work named "halloweenmath package".
+
+Copyright (C) 2017 by Gustavo MEZZETTI.
+
+The 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
+ 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.
+
+April 25, 2017 (vers. 0.10a)
+
+\endpreamble
+
+\askonceonly
+
+\generate{
+ \file{halloweenmath.sty}{\from{\filename}{halloweenmath}}
+}
+
+\Msg{}
+
+\ifWritingToDirectoryOfTDS
+
+\Msg{Installation finished. \space Check that the proposed directory}
+\Msg{\space\space\space\space\showdirectory{tex/latex/halloweenmath}}
+\Msg{has been correctly updated.}
+
+\else
+
+\Msg{To finish the installation, please move the following files into}
+\Msg{a directory where LaTeX looks for inputs files:}
+\Msg{}
+\Msg{\space\space\space\space halloweenmath.sty}
+
+\fi
+
+\Msg{}
+\Msg{Happy TeXing!}
+
+\endbatchfile
diff --git a/macros/latex/contrib/halloweenmath/manifest.txt b/macros/latex/contrib/halloweenmath/manifest.txt
new file mode 100644
index 0000000000..16e4a978ad
--- /dev/null
+++ b/macros/latex/contrib/halloweenmath/manifest.txt
@@ -0,0 +1,100 @@
+
+This is file `manifest.txt'.
+
+This file is part of a work named "halloweenmath package".
+
+Copyright (C) 2017 by Gustavo MEZZETTI.
+
+The 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
+ 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".
+
+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.
+
+April 25, 2017 (vers. 0.10a)
+
+
+
+MEANING OF THE TERM "Work"
+==========================
+
+In the case of the halloweenmath package, the "Work" is the collection
+of the following 4 files:
+
+00readme.txt -- start by reading this file
+manifest.txt -- the file you are reading now
+halloweenmath.dtx -- main source file
+halloweenmath.ins -- installation script
+
+If you have received the 4 files listed above, you possess an integral
+copy of the halloweenmath package.
+
+
+
+MEANING OF THE TERM "Compiled Work"
+===================================
+
+In the case of the halloweenmath package, a "Compiled Work" is the
+collection of:
+
+a) the following 2 files that are also part of the "Work" (see above):
+
+00readme.txt
+manifest.txt
+
+AND
+b) the following 2 files:
+
+halloweenmath.sty -- the halloweenmath LaTeX package
+halloweenmath.dvi -- full documentation in DVI format
+
+You may, at your option, substitute the file `halloweenmath.dvi' with
+either one (or both) of the following two files:
+
+halloweenmath.pdf -- full documentation in PDF
+halloweenmath-doc.pdf -- overview of the halloweenmath package (PDF)
+
+but at least one among the files `halloweenmath.dvi',
+`halloweenmath.pdf', and `halloweenmath-doc.pdf' must be included in a
+"Compiled Work" that you intend to distribute. The file
+`halloweenmath.pdf' is obtained by submitting to the program pdflatex
+the file `halloweenmath.dtx', following the same steps as those
+explained in `00readme.txt' under the title "How to generate the
+documentation".
+
+
+
+ANCILLARY FILES
+===============
+
+The package of files distributed through the Comprehensive TeX Archive
+Network (CTAN) includes also the following five files:
+
+README -- guide to directory contents
+halloweenmath-doc.pdf -- overview of the halloweenmath package (PDF)
+halloweenmath-man.pdf -- user's manual for this same package (PDF)
+halloweenmath-man.tex -- LaTeX source of the preceding item
+Makefile -- Makefile to generate code or documentation
+
+These five files are included only for convenience's sake and are _not_
+a required part of the halloweenmath package (of course you may, if you
+wish, include them in your distribution too).
+
+
+
+COMMENT
+=======
+
+Please remember that, in order to distribute a LPPL-compliant copy of
+the halloweenmath package, it suffices to distribute only the 4 files
+that constitute the "Work".