fact: Definition ab_cokernel {G : Group@{u}} {A : AbGroup@{u}} (f : GroupHomomorphism G A) : AbGroup := QuotientAbGroup _ (grp_image f).
imports: Basics Types Classes.interfaces.canonical_names (Zero, zero) Classes.interfaces.abstract_algebra (IsAbGroup(..), abgroup_group, abgroup_commutative) Algebra.Groups.Group Algebra.Groups.Subgroup Algebra.Groups.QuotientGroup WildCat