proposition: Lemma isziso_from_Pullback_to_Pullback {a b c : C} {f : b --> a} {g : c --> a} (Pb Pb': Pullback f g) : is_z_isomorphism (from_Pullback_to_Pullback Pb Pb').
proof: Proof. exists (from_Pullback_to_Pullback Pb' Pb). apply are_inverses_from_Pullback_to_Pullback. Defined.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.TransportMorphisms UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Limits.Terminal UniMath.CategoryTheory.Limits.BinProducts UniMath.CategoryTheory.Limits.Equalizers UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.Monics