fact: Definition is_left_lifting_lift {k : z --> y} (θ : f ==> k · g) : 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