proposition: Lemma isiso_from_Pullback_to_Pullback {a b c : C} {f : C⟦b, a⟧} {g : C⟦c, a⟧} (Pb Pb': Pullback f g) : is_iso (from_Pullback_to_Pullback Pb Pb').
proof: Proof. apply (is_iso_qinv _ (from_Pullback_to_Pullback Pb' Pb)). apply are_inverses_from_Pullback_to_Pullback. Defined.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.MoreFoundations.Tactics UniMath.Combinatorics.StandardFiniteSets UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Limits.Graphs.Limits UniMath.CategoryTheory.Limits.Graphs.Colimits