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\title{GELL\-MU\\[0.25\baselineskip] Introductory Survey}
\date{Last updated: \today{} }
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\author{William F. Hammond}
\begin{document}
\begin{center}\LARGE\bfseries{}
GELL\-MU\\[0.25\baselineskip] Introductory Survey
\end{center}
\begin{center}\large\bfseries{}
A Bridge for Authors from \LaTeX{} to XML
\end{center}
\begin{center}\Large\bfseries{}
\textsl{William F. Hammond}
\end{center}
\begin{center}
\large\bfseries{}
Last updated: \today{}
\end{center}
\medskip
\begin{flushleft}\large\bfseries{}
Recent\end{flushleft}
\begin{itemize}
\item \textbf{Download}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/tarball.html} (v. 0.8.4.1, 6 July 2007) \\{} Since the version 0.8.0.5 release in October 2004, ``regular'' \textsc{GELL\-MU} has provided a reliable dual presentation route for math articles written in \LaTeX{}-like source language to (a) print and (b) online display in \textsc{XHTML} extended by Mathematical Markup Language (\textsc{MathML})\footnote{URI: http://www.w3.org/Math/}. \
\item (22 July 2007) Video, slides, and pre-meeting notes from my talk \textbf{\emph{Dual Presentation with Math from one Source}}\footnote{URI: http://math.albany.edu/math/pers/hammond/Presen/Tug2007/} on July 19 at \textsc{TUG} 2007\footnote{URI: http://www.tug.org/tug2007/} in San Diego. \
\item \label{userdoc}Latest online version of the \textbf{\emph{Introductory User's Guide to \emph{Regular} \textsc{GELL\-MU}}}: \begin{menulist}
\item \textbf{XHTML+MathML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/userdoc.xhtml}
\item \textbf{classical HTML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/userdoc.html}
\item \textbf{PDF:} formatted for \textbf{8.5 x 11 in.}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/userdoc.pdf}
\item \textbf{DVI:} formatted for \textbf{8.5 x 11 in.}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/userdoc.dvi}
\item \textbf{\textsc{GELLMU} source}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/userdoc.glm}
\end{menulist}
\item \label{manual}Latest online version of the \textbf{\emph{GELLMU Manual}}: \begin{menulist}
\item \textbf{XHTML+MathML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/glman/glman.xhtml}
\item \textbf{classical HTML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/glman/glman.html}
\item \textbf{PDF:} formatted for \textbf{8.5 x 11 in.}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/glman/glman.pdf}
\item \textbf{DVI:} formatted for \textbf{8.5 x 11 in.}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/glman/glman.dvi}
\item \textbf{Plain text}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/glman/glman.txt} (made from classical \textsc{HTML} using \textsl{lynx})
\item \textbf{\textsc{GELLMU} source}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/glman/glman.glm}
\end{menulist}
\item Author-level XML document type definition\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/xml/axgellmu.dtd} for the markup used in \emph{Regular} \textsc{GELL\-MU}. \ It's the ``side entrance'' in the Regular \textsc{GELL\-MU} Flow Chart\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/glman/glman.html\#flow}. \ \begin{center}
\includegraphics[width=0.3\textwidth]{gcompsm}
\end{center}
\item \textsc{MathML} Demos of past articles from \emph{The New York Journal of Mathematics}\footnote{URI: http://math.albany.edu/math/demos/nyjm} made with \textsc{GELL\-MU}. \ (15 Oct. 2006: These have been rebuilt to be safe in Firefox 1.5.0.7.)
\item Understand the system by \textbf{studying examples}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/examples/}. \
\item The latest \emph{fully tested} version of the \textbf{syntactic translator} \textbf{\texttt{gellmu.el}}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/gellmu.el}, which is all that is required for \emph{basic} \textsc{GELL\-MU}. \
\end{itemize}\section*{Table of Contents}
\begin{Toclist}
\item[]{1\ \ Introduction\dotfill{}~\pageref{SU-1}}
\item[]{2\ \ First Demonstrations\dotfill{}~\pageref{SU-2}}
\item[]{3\ \ Can Content-Level \textsc{MathML} be a Derived Format?\dotfill{}~\pageref{SU-3}}
\item[]{4\ \ Brief Introductions\dotfill{}~\pageref{SU-4}}
\begin{toclist}\normalsize
\item[]{4.1\ \ Basic \textsc{GELL\-MU}\dotfill{}~\pageref{SU-4.1}}
\item[]{4.2\ \ Advanced \textsc{GELL\-MU}\dotfill{}~\pageref{SU-4.2}}
\item[]{4.3\ \ \emph{Regular} \textsc{GELL\-MU}: The Didactic Production System\dotfill{}~\pageref{SU-4.3}}
\item[]{4.4\ \ Other Production Systems\dotfill{}~\pageref{SU-4.4}}
\end{toclist}
\item[]{5\ \ Materials\dotfill{}~\pageref{SU-5}}
\item[]{6\ \ Relevant Public Discussion and Comment\dotfill{}~\pageref{SU-6}}
\item[]{7\ \ Pointers to a Few Related Things\dotfill{}~\pageref{SU-7}}
\item[]{8\ \ About this Document\dotfill{}~\pageref{SU-8}}
\end{Toclist}
\section*{1\ \ \label{SU-1}\label{intro}Introduction}
\par{Generalized Extensible \LaTeX{}-Like Markup (\textsc{GELL\-MU}) is my concept for using \LaTeX{}-like markup to create documents in an easy plain text format that may be faithfully converted to high-powered documents marked up under \textsc{SGML}. \ \TeX{} is the classical typesetting markup language (with robust handling of mathematics) that was created by Donald E. Knuth of Stanford University around 1980. \ The \emph{\LaTeX{} document preparation system} was created shortly thereafter by Leslie Lamport of Digital Equipment Corporation. \ \LaTeX{} is a simplified markup interface to \TeX{} designed to let ``the user concentrate on the structure of the text'' rather than on typesetting. \ \textsc{SGML}, an abbreviation for \emph{Standard Generalized Markup Language} (ISO 8879:1986), is the name of a family of markup languages, unspecified in number, designed for efficient automatic text processing with shared tools of a certain type. \
}
\par{During the period 1993-1998 the most familiar example of a markup language in the \textsc{SGML} family was \emph{Hypertext Markup Language (\textsc{HTML})}, the now familiar language of the World Wide Web\footnote{URI: http://www.w3.org/}. \ \textsc{HTML} is a rather low-powered member of the \textsc{SGML} family. \ The notion of ``power'' for a language under the umbrella of \textsc{SGML} has to do with the number of available translations to other document languages, both within and without \textsc{SGML}. \
}
\par{One of the ideas in my design for \textsc{GELL\-MU} is that with existing stable freely available \textsc{SGML} tools one may go to almost any presentation format. \ For the community of mathematicians and scientists, who have become accustomed to using \TeX{} to create finely typeset documents for printing, this design provides a way automatically to create other carefully crafted forms from a single source document without over-burdening Donald Knuth's program \TeX{}. \
}
\par{For typeset printed presentation, \textsc{SGML}-based processing to the language \TeX{} should be optimal, while \textsc{SGML}-based processing to Lamport (v.2) \LaTeX{} is used in didactic examples found below. \ (See also \texttt{"jadetex"} at The Comprehensive \TeX{} Archive Network (\textsc{CTAN}); brief comment on \texttt{"jade"} may be found below.) Most of the magic is due to Charles Goldfarb, the inventor of \textsc{SGML}, James Clark, the author of \texttt{"nsgmls"}, and David Megginson, the author of \texttt{"sgmlspl"}. \ The \textsc{GELL\-MU} to \textsc{SGML} transliterator that I am still writing could have been done in many languages, but ELISP, the language of GNU Emacs, probably the best-documented of all languages, and probably also the most easy-to-debug general purpose language, seemed to be just right for this. \ Beyond that I am grateful to Richard Stallman for encouragement and answers. \ Of course, when things do not work, the problems should in no way be attributed even in part to the antecedent work. \
}
\section*{2\ \ \label{SU-2}\label{demos}First Demonstrations}
\par{For a quick look, intended for those who know \LaTeX{}, there is \emph{A Silly Little GELLMU Article}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.html} of about three printed pages. \ Alongside the \textsc{HTML} form of this article are other versions: \begin{itemize}
\item the original \textsc{GELL\-MU} source markup\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.glm}. \
\item its syntactic translation to an \textsc{SGML} document\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.sgml}, involving only minimal knowledge of the document type. \
\item its translation to an \textsc{XML} dialect\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.xml}, that is essentially equivalent to the source. \
\item \LaTeX{} source that was generated from the \textsc{XML} version\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.ltx}
\item \textsc{DVI}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.dvi} made from the \LaTeX{} version. \
\item \textsc{PDF}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.pdf} made with \textsl{pdflatex}. \
\item \textsc{XHTML+MathML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/silly.xhtml}. \
\end{itemize} And yes, of course, both \textsc{HTML} versions were generated from the \textsc{XML} version. \
}
\section*{3\ \ \label{SU-3}\label{mathml}Can Content-Level MathML be a Derived Format?}
\par{Mathematical Markup Language (\textsc{MathML}) is a language under development by the World Wide Web Consortium (\textsc{W3C})\footnote{URI: http://www.w3.org/} for (1) the display of mathematics in ordinary web pages and (2) automated interchange of mathematical segments among web-compatible software applications. \
}
\par{Corresponding to (1) and (2) above the \textsc{W3C} has provided presentation and content-level versions of \textsc{MathML}. \
}
\par{While \textsc{MathML}, which is an \textsc{XML} language (formally ``application''), is verbose to a point that makes its writing by human authors almost impossible, the \textsc{W3C} project has not undertaken to provide a language suitable for authors. \ Moreover, one cannot robustly translate well-structured standard \LaTeX{} or \TeX{} math segments into \textsc{MathML} without the discipline of rules that are difficult to both to formulate and to enforce. \
}
\par{The concept of \emph{generalized \LaTeX{}} in the \textsc{GELL\-MU} Project provides such discipline. \
}
\par{The version of ``Regular'' (see \S{}4.3) \textsc{GELL\-MU} in the \textbf{tarball}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/tarball.html}, has, since August 2004, provided translation of generalized \LaTeX{} source markup under the \emph{article} document type to \textsc{HTML} with presentation-level \textsc{MathML} as well as translation to ordinary \LaTeX{}. \
}
\par{The key question in designing a system sufficient for generation of mathematics under an umbrella like content-level \textsc{MathML} either using highly specialized \LaTeX{} or using an \textsc{SGML} or \textsc{XML} language for authors is how far authors will be willing to diverge from past habits. \
}
\par{The Math Benchmark Document\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/authordtd/} offers an example of various mathematical segments that one might want to have automatically translated to a language with relative semantics such as content-level \textsc{MathML}. \
}
\par{There is something of an explanation (now in early draft stage\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/notation}), familiar to many research mathematicians but perhaps not to so many computer scientists, of why most legacy \TeX{}/\LaTeX{} markup of mathematics is \textbf{not} ambiguous for robots when augmented by adequate ``type'' information. \ Legacy practice has been to include ``type'' information in paper documents as part of an article's descriptive text. \ In a few words, mathematicians are usually careful and fussy about notation. \ \textsc{GELL\-MU} will eventually provide for ``declared symbols'' and optional associated alpha-numeric ``type'' information. \ Ultimately there should emerge a public formal object, the ``mathematical expression'' (\verb+mathexpr+) that is something like the ``regular expression'' (\verb+regexp+) that is familiar to users of \texttt{"ed"}, ELISP, ``Perl'', etc. \ One will want a separate, probably simpler syntax for the specification of the \emph{type} of a \verb+mathexpr+. \
}
\par{My philosophy, and I think the only realistic philosophy, is that such types for mathexprs should involve \emph{relative}, rather than \emph{absolute}, semantics. \
}
\par{One of the most basic types is categorical ``morphism'', which is a generalization of a calculus student's notion of ``function''; for much that is of interest to many, the notion of function will suffice, provided that each function symbol is understood to imply ``domain'' and ``target'' with ``target'' not always the same as ``image'' or ``range''. \ Regardless, users may conceptualize ``morphisms'' as ``functions''. \
}
\section*{4\ \ \label{SU-4}\label{briefIntro}Brief Introductions}
\par{To summarize there are two concepts in this project. \
}
\subsection*{4.1\ \ \label{SU-4.1}Basic GELL\-MU}
\par{This may be useful for some authors familiar with \LaTeX{} who wish to write directly for an \textsc{SGML} or \textsc{XML} document type. \ It provides rudimentary \LaTeX{}-like commands with single argument syntax. \ \textsc{SGML} attribute strings may be entered using a single \LaTeX{}-like option. \
}
\par{It also offers a \LaTeX{}-like meta-command \emph{\textbackslash{}newcommand}, which provides for macros with arguments. \ See Using the \textsc{GELL\-MU} Syntactic Translator to Write \textsc{HTML}\footnote{URI: /\textasciitilde{}hammond/gellmu/ghtml.html}. \ For example, the previous anchor would be marked up in \textsc{HTML} as \begin{center}
\texttt{\stringUsing ... \stringHTML\string\string} \ ,
\end{center} and this is marked up somewhat more succinctly in \textsc{GELL\-MU} source as \begin{center}
\texttt{}\verb+\+\texttt{a[href="/\string~hammond/gellmu/ghtml.html"} \\{} \texttt{]}\verb+{+\texttt{Using ... }\verb+\+\texttt{kbd}\verb+{+\texttt{HTML}\verb+}+\texttt{}\verb+}+\texttt{} .
\end{center} With the \emph{newcommand} definition for \emph{\textbackslash{}href} \begin{center}
\texttt{}\verb+\+\texttt{newcommand}\verb+{+\texttt{}\verb+\+\texttt{href}\verb+}+\texttt{[2]}\verb+{+\texttt{}\verb+\+\texttt{a[href="\#1"]}\verb+{+\texttt{\#2}\verb+}+\texttt{}\verb+}+\texttt{}
\end{center} the even more succinct markup \begin{center}
\texttt{}\verb+\+\texttt{href}\verb+{+\texttt{/\string~hammond/gellmu/ghtml.html}\verb+}+\texttt{}\verb+{+\texttt{Using ... }\verb+\+\texttt{kbd}\verb+{+\texttt{HTML}\verb+}+\texttt{}\verb+}+\texttt{}
\end{center} suffices. \
}
\subsection*{4.2\ \ \label{SU-4.2}Advanced GELL\-MU}
\par{This goes beyond basic \LaTeX{}-like command / argument syntax to provide \LaTeX{}-like multiple argument / option syntax and also what might be called \LaTeX{}-like grammar including \emph{\textbackslash{}begin\{\ldots{}\}\textbackslash{}end} and, if desired, blank lines to initiate paragraphs. \
}
\par{When desired, advanced \textsc{GELL\-MU} has knowledge of a few command names, but the author must know the \textsc{SGML} or \textsc{XML} document type. \
}
\subsection*{4.3\ \ \label{SU-4.3}\label{reggellmu}\emph{Regular} GELL\-MU: The Didactic Production System}
\par{The didactic production system is a beginning at emulating \LaTeX{} with an \textsc{XML} document type. \ In fact, \LaTeX{} can be modeled more precisely with \textsc{SGML} than with \textsc{XML}. \
}
\par{The didactic production system consists of \begin{Menulist}
\item The \textsc{GELL\-MU} Syntactic Translator. \
\item An \textsc{SGML} document type. \
\item An \textsc{XML} document type. \
\item The following translators, coded in Perl under David Megginson's \textsl{sgmlspl} framework: \begin{enumerate}
\item from the \textsc{SGML} document type (\textsc{GELL\-MU} Syntactic Translator output) to the \textsc{XML} document type. \
\item from the \textsc{XML} document type to \textsc{HTML}. \ For this there are two routes: \begin{enumerate}
\item The up to date \textsc{XML} form of \textsc{HTML} extended by \textsc{MathML}. \
\item Classical \textsc{HTML} with pseudo-\TeX{} \textsc{ASCII} for math, still useful with terminal window browsers. \
\end{enumerate}
\item from the \textsc{XML} document type to \LaTeX{}
\end{enumerate}
\end{Menulist}
}
\par{There is validation of each stage of output. \ Indeed, validation of the \textsc{GELL\-MU} Syntactic Translator's \textsc{SGML} output is very useful for catching author errors. \ To assist with this there is line number alignment between the source and \textsc{GELL\-MU} Syntactic Translator output. \ If necessary\footnote{But only in very exceptional situations} one may intervene at any stage of the processing since the output of each stage is quite readable by humans. \
}
\par{The two document types are parallel; the \textsc{XML} version is intended to be the nearest \textsc{XML} approximation of the \textsc{SGML} version. \ The \textsc{SGML} version should be regarded as ``in-house'', while the \textsc{XML} version is suitable for export. \ (Usable, though not identical, source may be recovered from the \textsc{XML} document type.)
}
\par{The document types have been designed for translation to many output formats. \ I have the intention ultimately to write or find others to write translators from the \textsc{XML} document type to other formats. \
}
\par{Finally the \emph{article} document type may have value as a layout vehicle that is useful as an intermediate formatting stage for structure-rich document types such as \textsl{DocBook} and \textsl{TEI}, and I would encourage those who might be so inclined to think about writing translators from such document types to \textsc{GELL\-MU} \emph{article}. \
}
\par{The \emph{Brief Introduction to Regular \textsc{GELL\-MU}}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.xhtml} (in \textsc{XHTML+MathML}) is itself a \textsc{GELL\-MU} document. \ It deals mainly with the language. \ Various other versions are also available here: \begin{itemize}
\item the input source\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.glm}. \
\item the syntactic translation to \textsc{SGML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.sgml}. \
\item the translation to \textsc{XML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.xml}. \
\item translation to classical \textsc{HTML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.html}. \
\item the \LaTeX{} version\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.ltx}. \
\item \textsc{DVI} made from the \LaTeX{}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.dvi}. \
\item portrait \textsc{PDF} made from the \LaTeX{}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/iglm.pdf}
\end{itemize}
}
\subsection*{4.4\ \ \label{SU-4.4}Other Production Systems}
\par{An author may use \emph{advanced} \textsc{GELL\-MU} as a front end to many other \textsc{SGML} or \textsc{XML} production systems with appropriate setting of variables for the \textsc{GELL\-MU} Syntactic Translator. \
}
\section*{5\ \ \label{SU-5}\label{materials}Materials}
\par{All that one should need to get started is in the current tarball\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/tarball.html}. \ One should look at the user guide, the manual, both listed as ``Quick Anchors'' above, and the examples\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/examples/}. \ Note that the driver scripts found in the \texttt{bin} directory of the unpacked tarball may need editing for location names. \
}
\par{Note also that the tarball may be installed in a ``Windows'' system equipped with \textsl{Cygwin}, enhanced by a sufficient array of \textsl{Cygwin}-provided packages, using the Linux driver scripts. \
}
\par{In principle, it should also work on MacOS X, but I have no reports, and I have no idea what might be required to port it to earlier versions of MacOS. \
}
\par{Although the project was begun begun in June 1998, its alpha release was in July, 2001. \ It will not be considered to have reached beta stage until I have more knowledge about use experience of others. \
}
\par{Some older odds and ends may be found on the \textsc{GELL\-MU} veterans page\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/veterans.html}, and the very old page for early preview of materials\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/gellmum.html} is still available. \
}
\section*{6\ \ \label{SU-6}\label{discussion}Relevant Public Discussion and Comment}
\par{My annotations allude, though not entirely precisely, to the article \emph{The Cathedral and the Bazaar}\footnote{URI: http://www.redhat.com/knowledgebase/otherwhitepapers/whitepaper\_cathedral.html} by Eric Raymond. \ \begin{description}
\item[{Electronic Math Journals}]\footnote{URI: mailto:listserv@listserv.albany.edu}
Use ``subscribe EMJ'' in the BODY of a message.~\\{} There is an archive at the host site\footnote{URI: http://listserv.albany.edu:8080/archives/emj.html}.~\\{} This is a bazaar. \ Sometimes technical, sometimes economic or legal, sometimes other. \
\item[{\LaTeX{} Development}]\footnote{URI: mailto:listserv@relay.urz.uni-heidelberg.de}
Use ``subscribe LATEX-L'' in the BODY of a message.~\\{} Archive location, if any, unknown.~\\{} Neither a bazaar, nor a cathedral. \ Very sophisticated and technical. \ User questions are not wanted. \
\item[{\textsc{MathML} and the \textsc{HTML} Math WG}]\footnote{URI: mailto:www-math-request@w3.org}
Make your message SUBJECT ``subscribe''. \ Message BODY should be blank.~\\{} An archive will be found behind the W3C Math\footnote{URI: http://www.w3.org/Math/} web site.~\\{} This is a small bazaar in the nave of a cathedral. \ The cathedral ``chapter'' has its own private list. \ Many chapter members, not all, who speak in the nave seem to feel constrained to representation of the chapter. \
\item[{UseNet news on \textsc{SGML} (if you get ``news'')}]\footnote{URI: news:comp.text.sgml}
A bazaar with many, many important people. \ Sophisticated and technical, questions about \textsc{SGML} (but not \textsc{HTML}, nor http, nor ``the web'', ...) are usually answered well. \
\item[{UseNet news on \textsc{XML} (if you get ``news'')}]\footnote{URI: news:comp.text.xml}
A recent spin-off from the \textsc{SGML} discussion. \ Eventually it should operate at much higher volume than the \textsc{SGML} discussion. \
\end{description}
}
\section*{7\ \ \label{SU-7}\label{pointers}Pointers to a Few Related Things}
\begin{description}
\item[{\textbf{Slides from 2001}}]\footnote{URI: http://math.albany.edu/math/pers/hammond/Presen/tug2001/}
A presentation given at The University of Delaware during the 2001 annual meeting of \textsc{TUG}\footnote{URI: http://www.tug.org/tug2001/}. \
\item[{\emph{Blahtex}}]\footnote{URI: http://meta.wikimedia.org/wiki/Blahtex}
\emph{Blahtex} converts \LaTeX{}-like math markup to \textsc{MathML} for use with \emph{MediaWiki}\footnote{URI: http://en.wikipedia.org/wiki/MediaWiki}, which is wiki implementation software for \emph{Wikipedia}\footnote{URI: http://en.wikipedia.org/}. \
\item[{\emph{TBook}}]\footnote{URI: http://tbookdtd.sourceforge.net/}
The \emph{TBook} System for \textsc{XML} Authoring by Torsten Bronger. \
\item[{\emph{Using XML in ConTeXt}}]\footnote{URI: http://www.pragma-ade.com/xml.htm}
An indication that ConTeXt is moving into the XML world. \
\item[{MathML, Version 2.0, Second Edition}]\footnote{URI: http://www.w3.org/TR/MathML/}
A W3C recommendation (October 21, 2003). \
\item[{OMDoc: Open Mathematical Documents}]\footnote{URI: http://www.mathweb.org/omdoc/}
A content based XML markup format by Michael Kohlhase of Universit\"{a}t Saarlandes and Carnegie Mellon University for mathematics on the Internet that extends OpenMath\footnote{URI: http://www.openmath.org/} to the document level. \ Released November 1, 2000. \
\item[{Daniele Giacomini's Sgmltexi}]\footnote{URI: http://master.swlibero.org/\textasciitilde{}daniele/software/sgmltexi/}
\textsc{Sgmltexi} is the new (August 25, 2000) \textsc{SGML} model of \textsc{Texinfo}. \ It should be possible to have two way translation between the didactic \textsc{GELL\-MU} document type and \textsc{Sgmltexi} although one should not expect the two translations to be exact inverses of each other. \ This should be useful in deciding how to \begin{enumerate}
\item provide mathematics in \textsc{Texinfo}. \
\item eliminate the need for bifurcation between \TeX{} and \textsc{Info} in future versions of \textsc{Texinfo}. \
\end{enumerate}
\item[{Paul Gartside's MathZilla Site at Pittsburgh}] \par{~}
\emph{MathZilla} is a nickname for the version of Mozilla\footnote{URI: http://www.mozilla.org/} with internal knowledge of \textsc{MathML}. \ The site at \begin{center}
\url{http://pear.math.pitt.edu/mathzilla/}
\end{center} has Mathzilla demonstration pages and many related items of interest. \ It is the successor to his former site at Oxford. \
\item[{David Carlisle's \texttt{xmltex}}]\footnote{URI: http://www.dcarlisle.demon.co.uk/xmltex/}
\texttt{xmltex} uses \textsl{TeX}, the program, to parse (without validation) an \textsc{XML} document and then set it in \TeX{}, according to user rules written in code for \TeX{}, that govern what is done for each of the tags in the corresponding \textsc{XML} document type definition. \ The same items are also available at CTAN in \texttt{"macros/xmltex"}. \
\item[{Sebastian Rahtz's ``PassiveTeX'' at TEI.}]\footnote{URI: http://www.tei-c.org.uk/Software/passivetex/}
Uses \TeX{} as a formatting back end for documents prepared under an \textsc{XML} language according to an \textsc{XSL} stylesheet. \
\item[{\emph{TeX4ht}, htlatex, \ldots{} : Current work of Eitan Gurari at Ohio State University.}]\footnote{URI: http://www.cse.ohio-state.edu/\textasciitilde{}gurari/}
\hsf ~\\{} A new way to make \textsc{HTML} and \textsc{XML} versions of \TeX{} and \LaTeX{} documents. \ This is based on a C program \emph{TeX4ht}\footnote{URI: http://www.cse.ohio-state.edu/\textasciitilde{}gurari/TeX4ht/mn.html}, and on a related macro package for \TeX{}. \ The macro package causes ``\TeX{}, the program'', to add specials to its \textsc{DVI} output. \ The program TeX4ht operates on a \textsc{DVI} that has been so prepared and makes \textsc{HTML} or \textsc{XML}. \ (The \textsc{DVI} format has the abstract structure of a classical assembly language. \ There are several ``special'' instructions that serve as wildcards. \ These ``specials'' are of use only to processors that know about them on a case-by-case basis. \ They \emph{should}, in theory, be ignored by processors that do not recognize them.) \par{In recent editions of \textsc{TUG}'s TeXLive a convenient default interface for using \emph{TeX4ht} to make \textsc{HTML} from \LaTeX{} is the command \textsl{htlatex}. \
}
\item[{HyperLaTeX}] \par{~}
An early (mid 90's) package (unfortunately not on CTAN) for the production of \LaTeX{} and \textsc{HTML} from a single specialized \LaTeX{} source document. \ Hyperlatex\footnote{URI: http://www.cs.uu.nl/\textasciitilde{}otfried/Hyperlatex/} is somewhat similar to \textsc{GELL\-MU} in its use of an Emacs Lisp program for generating \textsc{HTML} though it seems not to provide a method for conscious writing under other \textsc{SGML} or \textsc{XML} document types. \
\item[{The \LaTeX{}3 Project.}] \par{~}
Information is available in the document section of the current \LaTeX{}2E base distribution under the filename \texttt{"ltx3info.tex"} (with \textsc{DVI} and Post\-Script version nearby). \ On the web one may consult the \textsc{PDF} version\footnote{URI: http://ctan.tug.org/tex-archive/macros/latex/doc/ltx3info.pdf}. \ Plans for \textsc{SGML} are mentioned in this document. \ There is a mailing list on the topic of \LaTeX{}3 development at the address \verb+LATEX-L@relay.urz.uni-heidelberg.de+. \
\item[{Doug Lovell's TeXML at IBM.}]\footnote{URI: http://www.alphaworks.ibm.com/formula/texml}
TeXML is an \textsc{XML} vocabulary for describing \TeX{} syntax. One writes an XSL style sheet to translate an \textsc{XML} into TeXML. \ A small, simple program then readily translates TeXML to \TeX{}. \ (A November, 1998 release.)
\item[{Smart Documents.}] \par{~}
There are various forms of ``smartness''. \ \textsc{SGML} will provide easily for all of them. \ See Richard Fateman's material on \emph{More Versatile Scientific Documents ...}\footnote{URI: http://http.cs.berkeley.edu/\textasciitilde{}fateman/MVSD.html}. \
\item[{Linux Documentation.}] \par{~}
The ``How To'' documents for Linux systems are based on an \textsc{SGML} language with ancestry in the \LaTeX{}-like language of the \textsc{QWERTZ} document formatting system from the University of Exeter (U.K.) in the early 1990's. \ The SGMLtools-Lite Project\footnote{URI: http://sgmltools-lite.sourceforge.net/} is a recent effort to bring Linux documents under the DocBook\footnote{URI: http://www.oasis-open.org/docbook/} language. \
\item[{Luc Maranget's Hevea}] \par{~}
\textsl{Hevea}\footnote{URI: http://cristal.inria.fr/\textasciitilde{}maranget/hevea/} is a \LaTeX{} to \textsc{HTML} translator, said to produce correct \textsc{HTML} 4.0. \
\item[{Latex2html and Latex2html-with-MathML.}] \par{~}
\hsf ~\\{} The familiar Perl package \textsl{latex2html}\footnote{URI: http://www.ctan.org/tex-archive/support/latex2html/} gained popularity in math departments during the early days of the web not only by translating the \LaTeX{} commands that could be marked up into \textsc{HTML} but also by automatically putting out mathematics in graphic objects housed in \verb+"
"+ tags; the graphics were created with subprocesses that used \TeX{}, \textsl{dvips}, and some \textsl{netpbm} utilities. \ Many features have been added. \ \par{A 1998 variant\footnote{URI: http://www.geom.umn.edu/\textasciitilde{}ross/webtex/webtex/} at The Geometry Center offers the option of replacing the graphic objects with \textsc{MathML}\footnote{URI: http://www.w3.org/Math/} objects. \
}
\item[{The philosophy of Kernighan and Pike.}]\footnote{URI: http://math.albany.edu/math/pers/hammond/unixphil.html}
If you have never looked at their classic 1984 book, here are a few quoted paragraphs. \ Don't let their use of a trademark get in your way. \
\end{description}
\section*{8\ \ \label{SU-8}\label{aboutThis}About this Document}
\par{This document, which is primarily a web page, is itself a \emph{regular} \textsc{GELL\-MU} document (see \S{}4.3). \ Versions of this document other than the \textsc{HTML} version include the original \textsc{GELL\-MU} source\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/igl.glm}, its translation to \textsc{XML}\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/igl.xml} (from which the HTML version is derived), the derived translation to XHTML+MathML\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/igl.xhtml}, and the derived \LaTeX{} source\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/igl.ltx} from which a device independent (DVI)\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/igl.dvi} file and a file in Adobe's portable document format (PDF)\footnote{URI: http://www.albany.edu/\textasciitilde{}hammond/gellmu/igl/igl.pdf} were compiled. \ The PDF copy, which was generated using the free program \textsl{pdflatex}, is tuned for printing on 8.5 x 11 inch paper by those who have yet to equip themselves (freely) for printing DVI. \
}
\end{document}