fact: Definition projection_split_to_kernel {B A : AbGroup} (E : AbSES B A) {s : B $-> E} (h : projection _ $o s == idmap) : (middle E) $-> (@ab_kernel E B (projection _)).
imports: Basics Types Truncations.Core HSet WildCat Groups.QuotientGroup Groups.ShortExactSequence AbelianGroup AbGroups.Biproduct AbHom Homotopy.ExactSequence Pointed Modalities.ReflectiveSubuniverse