`{Funext} {A : AbGroup} : (@ab_codiagonal A) $o direct_sum_swap = ab_codiagonal. Proof. apply equiv_path_grouphomomorphism. intro a; cbn. exact (abgroup_commutative _ _ _). Defined.
Require Import Basics Types Truncations.Core. Require Import WildCat. Require Import HSet. Require Import AbelianGroup. Require Import Modalities.ReflectiveSubuniverse.