fact: Definition nat_z_iso {C D : precategory_data} (F G : C ⟶ D) : UU := ∑ (μ : F ⟹ G), is_nat_z_iso μ.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.TransportMorphisms UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.Univalence