proposition: Lemma issymmapSet {X : apSet} : ∏ x y : X, x # y -> y # x.
proof: Proof. exact (pr1 (pr2 (pr2 (pr2 X)))). Qed.
imports: UniMath.Algebra.BinaryOperations UniMath.Foundations.Propositions UniMath.MoreFoundations.Sets UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions