fact: Definition is_left_extension_extend {k : y --> z} (θ : f ==> g · k) : h ==> k := invmap (make_weq _ (Hτ k)) θ.
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