proposition: Lemma isaprop_isEqualizer {x y z : C} (f g : y --> z) (e : x --> y) (H : e · f = e · g) : isaprop (isEqualizer f g e H).
proof: Proof. repeat (apply impred; intro). apply isapropiscontr. Defined.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Monics UniMath.CategoryTheory.Retracts