Proposition isaprop_is_left_extension {h : y --> z} (τ : f ==> g · h) : isaprop (is_left_extension τ). Proof. use impred ; intro. apply isapropisweq. Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Prelude. Require Import UniMath.Bicategories.Core.Bicat. Import Bicat.Notations. Require Import UniMath.Bicategories.Core.Examples.OpMorBicat. Require Import UniMath.Bicategories.Core.Examples.OpCellBicat.