`{Funext} {A B X : AbGroup} (phi psi : ab_biprod A B $-> X) : (phi $o ab_biprod_inl == psi $o ab_biprod_inl) * (phi $o ab_biprod_inr == psi $o ab_biprod_inr) <~> phi == psi. Proof. apply equiv_iff_hprop. - exact (uncurry ab_biprod_ind_homotopy). - exact (fun h => (fun a => h _, fun b => h _)). Defined.
Require Import Basics Types Truncations.Core. Require Import WildCat. Require Import HSet. Require Import AbelianGroup. Require Import Modalities.ReflectiveSubuniverse.