fact: Definition is_z_iso_to_is_inv2cell {a b : B} {f g : hom a b} (α : f ==> g) (Hα : is_z_isomorphism α) : is_invertible_2cell α.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.Bicategories.Core.Bicat