Lemma isirrefltightapSet {X : tightapSet} : ∏ x : X, ¬ (x ≠ x). Proof. exact isirreflapSet. Qed.
Require Import UniMath.Foundations.Propositions. Require Import UniMath.MoreFoundations.Sets. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.DecidablePropositions.