SgtMook/sympy — comment on commit 130b92a95d8f799cc7474f8ae52d103e0c1bb84f
File: sympy/core/tests/test_numbers.py line 344
By asmeurer:

Ditto for all other symmetric cases. Try to create all possible test cases combining the four operations and finite positive, finite negative, zero, infinity, negative infinity, complex infinity, finite complex (I), and nan (and remember to do both directions, like `a*b` and `b*a`).