fact: Record AbSES' {B A : AbGroup@{u}} := Build_AbSES { middle : AbGroup@{u}; inclusion : A $-> middle; projection : middle $-> B; isembedding_inclusion : IsEmbedding inclusion; issurjection_projection : IsSurjection projection; isexact_inclusion_projection : IsExact (Tr (-1)) inclusion projection; }.
imports: Basics Types Truncations.Core HSet WildCat Groups.QuotientGroup Groups.ShortExactSequence AbelianGroup AbGroups.Biproduct AbHom Homotopy.ExactSequence Pointed Modalities.ReflectiveSubuniverse