Allow TeXification in <code> tags.

Question

Some special characters, e.g. *, _ and \ have special meaning in Markdown syntax, but these are also commonly used in TeX equations too. This caused some equations, e.g. \alpha^{-1}_{-1} + \beta_{-1} fails to render properly (see my answer to Math markup, diagrams, etc. — pointers please).

In Math Overflow it is resolved by allowing TeXification in inline code. Since those characters won't be considered special inside backquotes, and we seldom need to write inline code in math, it is perfect for holding TeX equations without changing the backend.

To allow TeXification inside code tag, we just need to edit the config, and remove "code" from the skipTags: config.

Of course, this will make the equation have an ugly gray background. I disagree that all <code> should be made to have a white background, because this makes all code blocks to have a white background on gray background. Instead, I prefer the whiten the <code> only if it contains TeX equation.

In summary, I propose the following change to math-tex.js:

Find the var b=...; line, replace with:

var b='MathJax.Hub.Config({imageFont:null,extensions:["tex2jax.js","TeX/AMSmath.js","TeX/noUndefined.js"],jax:["input/TeX","output/HTML-CSS"],TeX:{noUndefined:{attributes:{mathcolor:"red",mathbackground:"#FFEEEE",mathsize:"90%"}}},tex2jax:{skipTags:["script","noscript","style","textarea","pre"],ignoreClass:"tex2jax_ignore|dno"},});MathJax.Hub.Register.StartupHook("End",function(){$("code > .MathJax").parent().css({"background-color":"transparent"})});MathJax.Hub.Startup.onload();';

This will allow TeXification in <code> tag (at the same time, solve the editing comment problem).

Answer 1

I am marking this status-completed, although the this doesn't actually corresponds to the initial request.

Now everything between $...$ and ＄＄...＄＄ will not be parsed by the Markdown parser on the server side. This only applies for new/edited posts.

$\alpha^{-1}_{-1} + \beta_{-1}$

$\alpha^{-1}_{-1} + \beta_{-1}$

$$\alpha^{-1}_{-1} + \beta_{-1}$$

＄＄\alpha^{-1}_{-1} + \beta_{-1}＄＄

Note that preview doesn't reflect the change yet (done). This also won't work in AMS environment such as align (yet?).

\begin{align} \alpha^{-1}{-1} &= \beta{-1} \ \gamma^{-1}{-1} &= \delta{-1} \ \end{align}

\begin{align}
\alpha^{-1}_{-1} &= \beta_{-1} \\
\gamma^{-1}_{-1} &= \delta_{-1} \\
\end{align}

\begin{align} \alpha^{-1}_{-1} &= \beta_{-1} \\ \gamma^{-1}_{-1} &= \delta_{-1} \\ \end{align}

\begin{align}
\alpha^{-1}\_{-1} &= \beta_{-1} \\\\
\gamma^{-1}\_{-1} &= \delta_{-1} \\\\
\end{align}