wrong newcommand preparsing:
the directive
```
\newcommand{\ol}{\overline}
```
transforms
```
$\ol{D(z_0,r)}$
```
into
```
<math>\overline</math>
```
but the correct output should be
```
<math>\overline{D(z_0,r)}</math>
```
In LaTeX it properly works.
Edit: changing the aforementioned latex directive into
```
\newcommand{\ol}[1]{\overline{#1}}
```
texla properly wokrs and returns
```
<math>\overline{ D(z_0,r) }</math>
```
If we have to manually change the `\def` directive into `\newcommand` we can see how the command is used and adapt the `\newcommand` definition, but we may encounter someone who uses the `\newcommand` directive in the concise way, and that would break mediawiki. We have to adapt how newcommand is preparsed, and it will be a bit tough