proposition: Lemma is_z_iso_comp_is_z_iso {C : category} {a b c : ob C} (f : C⟦a, b⟧) (g : C⟦b, c⟧) : is_z_isomorphism f -> is_z_isomorphism g -> is_z_isomorphism (f · g).
proof: Proof. intros Hf Hg. apply (is_z_iso_comp_of_is_z_isos f g Hf Hg). Defined.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.MoreFoundations.PartA UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Adjunctions.Core UniMath.CategoryTheory.Equivalences.Core UniMath.CategoryTheory.whiskering UniMath.CategoryTheory.PrecategoryBinProduct