proposition: Proposition isaprop_is_right_extension {h : y --> z} (τ : g · h ==> f) : isaprop (is_right_extension τ).
proof: Proof. use impred ; intro. apply isapropisweq. Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.Bicategories.Core.Bicat UniMath.Bicategories.Core.Examples.OpMorBicat UniMath.Bicategories.Core.Examples.OpCellBicat