∫ Утверждение Mathlib
instAddCommGroup
Mathlib.Combinatorics.Enumerative.IncidenceAlgebra
URI: https://scilib.ai/kg/mathlib#IncidenceAlgebra.instAddCommGroup
∫ Утверждение Mathlib
Mathlib.Combinatorics.Enumerative.IncidenceAlgebra
URI: https://scilib.ai/kg/mathlib#IncidenceAlgebra.instAddCommGroup