# tex4ht using $$...$$ in moving arguments

I'm using tex4ht to produce HTML that contains mathematical content to be rendered using MathJax.

This question is about inline mathematical content in moving arguments, such as \section{$$y^2$$} and \caption{$$y^2$$}.

## Working minimal example

The following code compiles fine:

\documentclass{article}
\begin{document}
\section{$y^2$}
\end{document}

## Non-working minimal example

Using $$...$$ within the moving argument makes the compilation fail:

\documentclass{article}
\begin{document}
\section{$$y^2$$}
\end{document}

## Compilation

For both the working, and the non-working minimum working example, I'm using the following command to compile:

make4ht -a debug mwe.tex "mathjax"

## texmf-dist/tex/generic/tex4ht/mathjax-latex-4ht.4ht

I think that this will likely come down to redefining \AltlMath from mathjax-latex-4ht.4ht, to make it robust. The default definition is:

\long\def\AltlMath#1\){\expandafter\alteqtoks{$$#1$$}\)}

## Question

How can I configure AltlMath to be robust so that $$...$$ works within moving arguments?

Footnote: changing the .tex file is not an option :)

The MathJax configuration for TeX4ht provides command for commands that cause issues in sections: \fixmathjaxtoc. The problem is that some commands cause issues when they are written to the TOC file.

Try this config file:

\Preamble{xhtml}

\fixmathjaxtoc$$\fixmathjaxtoc$$
\begin{document}
\EndPreamble

This is the result:

• Ah, of course! That's wonderful, thank you so much. I do fully intend to help with the documentation of tex4ht once work allows. Thank you! Feb 18 at 13:43
• @cmhughes I've added this to TeX4ht sources. It would be great if you could take a look at the docs! I found that this issue is even already described in the draft Feb 18 at 19:16
• This looks great, thanks for the link. I assume the source is still in your github. I'm hopeful to contribute to it once things calm down at work. I use make4ht and tex4ht a lot, and your help has been invaluable Feb 18 at 20:25
• @cmhughes yes, this pages is automatically generated using Github Actions from github.com/michal-h21/tex4ht-doc. It needs lot of work, spell checking, grammar checking, expanding sections with information from older documentation or from my answers here, for example. Feb 18 at 20:39

Is this helps you?

%%mwe.cfg
\Preamble{html}
\newtoks\eqtoks
\def\AltMath#1${\eqtoks{$#1$}% \HCode{\the\eqtoks}$}
\Configure{$}{}{}{\expandafter\AltMath} \def\AltlMathI#1\){\eqtoks{$$#1$$}% \HCode{\the\eqtoks}} \Configure{()}{\AltlMathI}{} \begin{document} \EndPreamble Modified TeX code: \section{\protect$$y^2$$} It works for me.... Please excuse, if not so .... • When I place this in mwe.cfg and run make4ht -m draft -a debug -c mwe.cfg mwe.tex the document does not compile. Did it compile for you? Feb 18 at 13:08 • Sorry, please check the update .... Feb 18 at 13:26 • Thanks for looking at this. As I noted in my question: changing the .tex file is not an option :) I know that I can add \protect to all of these, but if that were an option, then I would simply change them all to$...$. Feb 18 at 13:31 • I read your MWE, I thought that you don't want to change $$...$$ to$...\$1, but now I understood that don't want to give \protect` too....sorry.... Feb 18 at 13:40