mathlib3

daafd6f7 - chore(number_theory/pythagorean_triples): added doc-strings (#3787)

chore(number_theory/pythagorean_triples): added doc-strings (#3787) Added docstrings to: `pythagorean_triple_comm` `pythagorean_triple.zero` `mul` `mul_iff` Co-authored-by: Rob Lewis <Rob.y.lewis@gmail.com>