LaTeX code in annotation-xml leads to parsing error

[pkra]

I'm not sure what the problem is, but the code below gives a parsing error. "Show original MathML" indicates that the LaTeX preprocessor is processing the annotation-xml.

<math display="inline"><mrow></mrow><annotation encoding="application/x-tex">\{\begin{array}[]{cl}n &amp;\end{array}</annotation></math>

[pkra]

Sorry, I oversimplified. This happens with a semantics tag as well.

<math><semantics><mrow></mrow><annotation encoding="application/x-tex">\begin{array}[]{cl} &amp; \end{array}</annotation></semantics></math>``

[dpvc]

OK, looks like another case of where running tex2jax before mml2jax causes problems. I guess we should force mml2jax to run first (this is not hard, since the preprocessors can be given priorities for just this reason).

[fred-wang]

I'm setting adding this to the 2.3 milestone list.

Another option seems to add annotation element to the list of tags that the tex2jax should not process. I'm going to try this first so that we can keep the tex2jax and mml2jax to run in parallel.

[fred-wang]

So adding annotation to the ASCIIMath/TeX's skipTags indeed works. I just modified the default config though, I think the other will work when I run the script to combine the config files (IIRC, Peter and I wonder the same for some localization config).

[fred-wang]

So people could actually also do

           <math><mtext>\begin{array}[]{cl} &amp; \end{array}</mtext></math>

and so probably the skipTags should actually contains the math element...

[fred-wang]

Parsing/issue484.html

[pkra]

@fred-wang I'm wondering if some people use math tags as TeX delimiter. Maybe skipping the annotation tag is less intrusive?

[dpvc]

I think it is OK to use the <math> tag, because you can't use that as a delimiter for the tex2jax preprocessor. The people who use <math> to delimit TeX use content management systems that handle the <math> tags on the server before sending it to the browser, long before MathJax runs. So that should work.

I'm wondering about the HTML5 use of HTML tags in <mtext>, so that you could have something like

<math>
  <mtext>
    <span>This is math: $x+1$</span>
  </mtext>
</math>

where math does want to be processed inside the <math> tag. But we don't handle such HTML tags anyway, and even if we did, this would have to be handled differently, so I guess this isn't a problem.

One problem with this approach is that IE < 8 doesn't properly nest unknown tags, so adding "math" to the skipTags array won't fix the problem in early versions of IE (or later versions emulating earlier versions).

The alternative is to use the preprocessor priority mechanism to ensure that the mml2jax extension runs before the tex2jax extension, so that the <math> will be removed from the page (into the MathJax <script> tags) before tex is processed. That might be more reliable.

[fred-wang]

Can you tell me how the preprocessor priority mechanism works? (or should I listens signals for input MathML ready in the TeX and AsciiMath extensions?)

[dpvc]

The MathJax.Hub.Register.PreProcessor() call takes an optional second argument that is the pre-processor's priority. The default is 10, as I recall, so setting the mml2jax priority to something like 5 should do the trick (lower priorities are run first).

[fred-wang]

OK, I've created a new branch issue485-bis

=> Ready For Review

BTW, this was also In testsuite:
Parsing/issue484.html

[dpvc]

Line 215 of unpacked/extensions/mml2jax.js should be

MathJax.Hub.Register.PreProcessor(["PreProcess",MathJax.Extension.mml2jax],5);

The ,5 should be outside the array, so that it is the second argument to MathJax.Hub.Register.PreProcessor not the third element of the callback array (where it would become the first argument passed to MathJax.Extension.mml2jax.PreProcess).

[dpvc]

PS, I don't see the Parsing/issue484.html file. Can you check that you committed it?