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