http://www.cis.ohio-state.edu/~gurari/
docs/mml-00/mml-00.html

••• Contents

••• Bird View

XML: XHTML, TEI, DocBOOK, ...

A LaTeX source:

 Gaussian of the form :
 \begin{eqnarray*}
 f( \epsilon , \delta s)
 \approx
 \frac
   {1}
   {\xi
    \sqrt{
      \frac{2 \pi}{\kappa}
      \left( 1 - \beta^2/2 \right)
   }}
 \exp \left [
   \frac
     {( \epsilon - \bar{\epsilon} )^2}
     {2}
   \frac
     {\kappa}
     {\xi^2 (1- \beta^2/2)}\right ]
 \end{eqnarray*}
 thus implying

The TEI/MathML output of TeX4ht:

 <!--l. 5--><div type="p"><p>Gaussian of the form :
 
 <!--l. 6--><formula notation="mathml"
 rend="block"><math xmlns="http://www.w3.org/1998/Math/MathML"
 display="block"> <mtable class="eqnarray-star"><mtr><mtd
 class="eqnarray-1"> <mi>f</mi><mrow
 ><mo>(</mo><mi>&#x03B5;</mi><mo>,</mo>
 <mi>&#x03B4;</mi><mi>s</mi><mo>)</mo></mrow> <mo>&#x2248;</mo>
 <mfrac><mrow ><mn>1</mn></mrow> <mrow
 ><mi>&#x03BE;</mi><msqrt><!--<mi>&#x2218;</mi>
    --><mfrac><mrow ><mn>2</mn><mi>&#x03C0;</mi></mrow>
  <mrow ><mi>&#x03BA;</mi></mrow></mfrac>   <mfenced
 open='(' close=')' ><mn>1</mn> <mo>&#x2212;</mo> <msup
 ><mi>&#x03B2;</mi><mrow ><mn>2</mn></mrow></msup
 ><mo>/</mo><mn>2</mn></mfenced></msqrt></mrow></mfrac><mo
 form="prefix" class="csname">exp</mo> <mfenced
 open='[' close=']' ><mfrac><mrow ><msup ><mrow
 ><mo>(</mo><mi>&#x03B5;</mi> <mo>&#x2212;</mo> <munderover
 accent='true'><mrow ><mi>&#x03B5;</mi></mrow><mrow ></mrow><mrow
 ><mo>&#x0304;</mo></mrow></munderover><mo>)</mo></mrow><mrow
 ><mn>2</mn></mrow></msup ></mrow>     <mrow
 ><mn>2</mn></mrow></mfrac>            <mfrac><mrow
 ><mi>&#x03BA;</mi></mrow> <mrow ><msup
 ><mi>&#x03BE;</mi><mrow ><mn>2</mn></mrow></msup ><mrow
 ><mo>(</mo><mn>1</mn> <mo>&#x2212;</mo> <msup
 ><mi>&#x03B2;</mi><mrow ><mn>2</mn></mrow></msup
 ><mo>/</mo><mn>2</mn><mo>)</mo></mrow></mrow></mfrac></mfenced></mtd><mtd
 class="eqnarray-2"> </mtd><mtd class="eqnarray-3"> </mtd><mtd
 class="eqnarray-4"> <mtext class="eqnarray"></mtext></mtd> </mtr></mtable>
 </math></formula>
 thus implying   </p></div>

The PassiveTeX Output:

••• LaTeX Foundations for TeX4ht

TeX4ht as a layer built on top of LaTeX:

• Generalizes the user interface ‘latex foo’
  • Extra start-up files besides ltx
  • But same compiler
• Seeds and configures the style files at the front end
• Filters the output at the back end

••• User Interfaces

Input: Standard LaTeX source file foo.tex

Output: Configurable, with a few built-in configurations provided.

••• Setting User Interfaces

A command line invokes LaTeX with appropriate configuration files.

••• Seeding Hooks

Native definition

Modified definition

Declared hooks

••• Configuring Hooks

• Extensive markup for content
• No XSLT-like transformations

••• Configuring Beyond Hooks

• Arbitrary character maps
• Math classes

  $a+1$ in TeX4ht	$a+1$ in LaTeX
  <mi>a</mi> <mo>+</mo> <mn>1</mn>	<ord>a</ord> <bin>+</bin> <ord>1</ord>

• Delimiter-oriented grouping

  $(a+b)^c$ in TeX4ht	$(a+b)^c$ in LaTeX
  <msup> <mrow>(...)</mrow> <mrow>...</mrow> </msup>	(...<msup> <mrow>)</mrow> <mrow >...</mrow> </msup>

••• Reversibility

• Presentation information is lost
  \vskip 2em
• With a few configured hints, logical information can be reconstructed.

  \begin{array}{cc} a & b \cr d & e \end{array}

  <mtable equalrows='false' equalcolumns='false' class='array'> <mtr><mtd><mi>a</mi></mtd>     <mtd><mi>b</mi></mtd> </mtr> <mtr><mtd><mi>d</mi></mtd>     <mtd><mi>e</mi></mtd> </mtr> <!--cc--></mtable>

• Demonstration:

  xhmlatex		latexexa.html		XSLT (xt)		latexexa.notex
  latexexa.tex		latexexa.pdf		xhm2latex.xsl		utf2any
  pdflatex		latexexa-1.pdf		pdflatex		latexexa-1.tex

••• Tasks for Postprocessors

• Tokenizing (XSLT): Xa + Xb = ab
  <mi>X</mi><mi>a</mi> <mo >+</mo>
  <mi>X</mi><mi>b</mi> <mo>=</mo>
  <mi>a</mi><mi>b</mi>
• Code moving (XSLT):
  <math class="equation">
  <mspace id="x1-2r1" class="label" width="0pt" />
      <mi>a</mi> <mo>+</mo> <mi>b</mi>
      <mo>=</mo> <mi>c</mi>
  </math>
• Syntax highlighting: x² + 4x + 4 = 0
  <mrow>
      <msup>
          <mi>x</mi>     <mrow><mn>2</mn></mrow>
      </msup>
      <mo>+</mo>
      <mrow>
          <mn>4</mn>
          <mo>&invisibletimes;</mo>
          <mi>x</mi>
      </mrow>
      <mo>+</mo>
      <mn>4</mn>
  </mrow>
  <mo>=</mo>
  <mn>0</mn>

••• Limitations

• Logical structures may pass through without markup, or with improper markup, if their definitions are not configured for TeX4ht.

• The native TeX engine deals mainly with presentation.
• Almost all of LaTeX is defined in style packages.
• Some of LaTeX math is defined outside the math environments of TeX.

• Content MathML requires new user-friendly TeX notation, or a postprocessor.

• The native TeX math model allows abuses, and might be in conflict with MathML.

Fixes (typically) are:

• Easy, for style code
• Painful, for content code
• Rarely required, for clean LaTeX source

• TeX4ht benefits enormously from its access to

• The LaTeX style files, at the front end
• The dvi directives and structures, at the back end

but could have been marginally improved from the addition of a few features to the TeX compiler:

• Compiler-based hooks at endpoints of subscripts, superscripts, and tables.
• Empty dvi groups for empty bases of subscripts and superscripts.

Don Knuth noticed the issue of subscripts and superscripts already in 1986 [4].

••• Historic Perspective

LaTeX

BibTeX2HTML, Gellmu, HTMX, HTeX, Hevea, HyperLaTeX, HyperTeX, LaTeX2HTML, LaTeX2hyp, Ltoh, Ltx2x, Math2HTML, TechExplorer, TeX2HTML, TeX2RTF, Texi2HTML, Tth, Vulcanize, WebEq Elsevier LaTeX2SGML, TeX4ht MicroPress TeXpider, Omega

*ML

1. Stand alone systems (limited to small subset of LaTeX)
2. Seeding dvi, and extracting text
3. Alternating the TeX engine + new primitives (of very little value, without TeX4ht-like configurations; non-portable)

••• PassiveTeX

A macro library in TeX for typesetting XSL Formatting Objects.

1. Convert the XML code to XSL-FO
   

   The MathML <math> elements pass through unchanged

2. Process the MathML embedded XSL-FO file with XMLTeX, under the PassiveTeX macros.
   

   The presentation Typesetting MathML with XMLTeX of David Carlisle discusses XMLTeX

••• References