`{Univalence} {A A' B C D D' : AbGroup} {E : AbSES B A'} {F : AbSES C D'} (f : A' $-> A) (g : D' $-> D) : AbSESMorphism (abses_direct_sum E F) (abses_direct_sum (abses_pushout f E) (abses_pushout g F)) := functor_abses_directsum (abses_pushout_morphism E f) (abses_pushout_morphism F g).
Require Import Basics Types Truncations.Core. Require Import WildCat Pointed.Core Homotopy.ExactSequence HIT.epi. Require Import Modalities.ReflectiveSubuniverse. Require Import AbelianGroup AbPushout AbHom AbGroups.Biproduct. Require Import AbSES.Core AbSES.DirectSum.