proposition: Lemma isirrefltightapSet {X : tightapSet} : ∏ x : X, ¬ (x ≠ x).
proof: Proof. exact isirreflapSet. Qed.
imports: UniMath.Algebra.BinaryOperations UniMath.Foundations.Propositions UniMath.MoreFoundations.Sets UniMath.MoreFoundations.Tactics UniMath.MoreFoundations.DecidablePropositions