Mathabx is a set of 3 mathematical symbols font series: matha,
mathb and mathx. They are defined by Metafont code and should
be of reasonable quality (bitmap output). Things change from
time to time, so there is no claim of stability (encoding,
metrics, design). The package includes Plain TeX and LaTeX
support macros.

Homepage:
https://ctan.org/pkg/mathabx
