∫ Утверждение Mathlib
instAddCommSemigroup
Mathlib.Algebra.Group.Opposite
URI: https://scilib.ai/kg/mathlib#MulOpposite.instAddCommSemigroup
∫ Утверждение Mathlib
Mathlib.Algebra.Group.Opposite
URI: https://scilib.ai/kg/mathlib#MulOpposite.instAddCommSemigroup