fact: Definition grp_cxfib {A B C : Group} {i : A $-> B} {f : B $-> C} (cx : IsComplex i f) : GroupHomomorphism A (grp_kernel f) := grp_kernel_corec _ cx.
imports: Basics Types Truncations.Core WildCat.Core Pointed Groups.Group Groups.Subgroup Groups.Kernel Homotopy.ExactSequence Modalities.Identity