fact: Definition left_lifting : UU := ∑ (h : z --> y) (τ : f ==> h · g), is_left_lifting τ.
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