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

David Carlisle d.p.carlisle at gmail.com
Fri Dec 18 23:24:46 CET 2015

```> changing the meaning of \mathchardef is also kind of incompatible (who knows who depends on the error message for whatever reason)

changing anything in tex is incompatible with something, as we both know:-)

> anyway, i'll add that fallback but there is no way back and it will not be under some 'option' control

options wouldn't be good, I agree. Just lead to incompatible setups
and confusion.

as I said in the last message not necessarily flagging for exactly
that change (I've not had long to think about it really, I'm just
working down our test failures and analysing the results) but wanted
to flag the issue and post the macro workaround, so that it could be
discussed (or at least known about:-)

David

> Hans
```