# [luatex] \mathchardef\foo=\mathcode`\x

David Carlisle d.p.carlisle at gmail.com
Fri Dec 18 23:20:18 CET 2015

```On 18 December 2015 at 21:57, jfbu <jfbu at free.fr> wrote:
> Hi David,
>

>
> I thought package lualatex-math by Philipp Stephani addressed
> these amsmath problems with \std at minus and \std at equal already ?

It does some things yes but standard amsmath loads without error
in luatex prior to .87. In 0.87 it gives errors while loading which will
affect a lot of documents unless we we can get it updated
(or adjust things so an  update not necessary) before tl2016.
lualatex-math hasn't been been updated since yesterday to adapt to
luatex 0.87 has it?

In the other message

> which has the \mathcode/\mathchardef issue if one has assigned
> an Umathcode to -

not sure what you mean by that?

In .87  assigning a \mathcode to - or assigning a Umathcode to it
are the same thing (and luatex always reports
the Umathcode version when you query it) so essentially
it will be the case that a umath ccode is assigned to - at that point.

David
```