proposition: Lemma only_isos_above_an_iso {c1 c2 : C} {f : C⟦c1,c2⟧} {d1 : D c1} {d2 : D c2} (ff : d1 -->[f] d2) : ∏ fi : is_z_isomorphism f, is_z_iso_disp (_ ,, fi) ff.
proof: Proof. intro fi. use tpair. * apply (uf c2 c1 (pr1 fi)). * split ; (apply proofirrelevance ; apply isapropifcontr ; apply uf). Qed.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.catiso UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Isos UniMath.CategoryTheory.DisplayedCats.Total UniMath.CategoryTheory.DisplayedCats.Univalence