\def in mathtext

Hi all,

I am using mathtext (via sphinx) for documenting larger physics
simulation software (https://www.yade-dem.org/sphinx/). I am converting
some docs from LaTeX, where I had defined simple macros like \def
\vec#1{\mathbf{#1}}, \curr#1{#1^{\circ}} or \let\eps\varepsilon -- to
unify notations and to make possible to change them easily globally.

Is it possible to define such _simple_ custom macros in mathtext itself?
If not, is there a simple way to monkey some internals of matplotlib in
python to have those?

I found support for \def mentioned only once, at
without any continuation on the subject.

Cheers, Vaclav