mathlib

dc6c365e - chore(algebra/group_with_zero/units/lemmas): `div_div_cancel_left'` (#18421)

chore(algebra/group_with_zero/units/lemmas): `div_div_cancel_left'` (#18421) This is the `group_with_zero` version of `div_div_cancel_left`. Forward-ported in https://github.com/leanprover-community/mathlib4/pull/2191