Comment 1 for bug 1814286

In fact, it looks like the compiler is ignoring \defs. For example:

\Dtcr [1] is defined by:

\def\Dtcr{\Dt_{\rm cr}}

Meanwhile other typical latex symbols are printing fine.

https://yade-dev.gitlab.io/trunk/formulation.html#estimation-of-by-wave-propagation-speed