# Mathjax 2.2 beta

UPDATE: Mathjax 2.2 final has been released.

We have deployed the latest Mathjax 2.2 beta on Math.SE. As with any beta release please post an answer to this question if you find any issues. We will be monitoring this thread closely along with the authors of Mathjax to ensure this release goes smoothly.

This release includes a number of new features and increased stability with over 40 bug fixes. For a list of resolved issues included in this release please check here.

There are a number of new features included as well. One feature we will be using is the Safe-mode extension. This will provide additional sanitation to protect our users from malicious javascript injections. For a list of other additional features included in this release check here.

• Have you enabled the AMScd support? :-) – Asaf Karagila May 6 '13 at 17:54
• Not at the moment - first things first @Asaf – Geoff Dalgas May 6 '13 at 17:57
• You should allow \arctanh \arcsinh \arccosh, etc. – Justin May 15 '13 at 3:24
• @gangqinlaohu: But they are really \arsinh, \artanh et cetera :-) – Jyrki Lahtonen May 15 '13 at 6:36
• @JyrkiLahtonen Thank you; didn't realize that. – Justin May 15 '13 at 23:51
• Is the final version deployed or are we still on beta? – Asaf Karagila May 21 '13 at 21:54
• One last thing, since the official release is out an deployed, is it possible to enable the AMScd support? It has been tested on a few pages (across the meta and the main site) and seems to work well. – Asaf Karagila May 24 '13 at 19:07
• Geoff, I thought that the AMScd package was automatically loaded, but apparently not anymore? – Asaf Karagila Jan 15 '14 at 20:22

You can experiment with the CD environment by including $\require{AMScd}$ in your post, and then using \begin{CD}...\end{CD}, as below.

Here is an example using CD:$\require{AMScd}$

\begin{CD} A @>a>> B\\@VVbV @VVcV\\ C @>d>> D \end{CD}

• Sweet!$\vphantom{}$ – Asaf Karagila May 6 '13 at 22:27
• Also, I have to ask, why AMScd and not some other diagram drawing package? (E.g. one that allows diagonal arrows.) – Asaf Karagila May 6 '13 at 22:40
• The AMS is one of the MathJax sponsors and they asked for it, so I implemented it. Also, its syntax is limited, so is readily handled, and it can be represented naturally in MathML, the format that underlies MathJax. Something like xypic has a much more extensive syntax, and does not fit naturally into the MathML language, so is much harder to implement in MathJax (there is an XyJax project that does implement it through SVG, and it is impressive). Arbitrary diagonal and arc arrows are not easily represented in MathML, and so need an implementation outside of MathML. – Davide Cervone May 6 '13 at 23:36
• Interesting, I figured it might be related to implementability. What are the odds of the AMS adding support for diagonal arrows? :-) – Asaf Karagila May 6 '13 at 23:40
• Not very likely, I would expect. It is not easy to do diagonal or arc arrows in TeX, either, and I think xypic uses postscript tricks to handle these things. MathJax would need to use something like SVG to do the same. While possible, it is not straight forward, and there is no MathML support for it, so it would have to be through internal extensions to MathML. I've kept that to a minimum (only one extra node type internally). – Davide Cervone May 6 '13 at 23:53
• I'm not sure if this is the proper place to report this: If you remove the label $b$ of the first vertical arrow, i.e., if you replace @VbVV by @VVV there is extra white space added between the first row of the diagram and the start of the vertical arrows: screen shot without label $b$ and with label $b$. I'm using Safari 5.1.9 (6534.59.8) if it matters. – Martin May 15 '13 at 19:39
• Thanks, I'll look into it. FWI, you can report bugs like that at the MathJax issue tracker. – Davide Cervone May 15 '13 at 21:11
• It looks like this may be a problem with the code that handles isolated stretchy characters in table cells (they are supposed to stretch to the height of the row). I'll investigate further, but it probably won't make it into the v2.2 release, which is scheduled for Friday. On the other hand, using @V{}VV is sufficient to avoid the extra space, while still not showing anything as a label, so that can be used as a work-around for now. – Davide Cervone May 16 '13 at 0:18
• We have pushed a fix for the problem to the CDN, so the arrows should work properly now, with or without labels. – Davide Cervone May 24 '13 at 22:59