Lemma isaprop_isapunop {X : tightapSet} (op :unop X) : isaprop (isapunop op). Proof. intros ap. apply impred_isaprop ; intro x. apply impred_isaprop ; intro y. apply isapropimpl. now apply pr2. Qed.
Require Import UniMath.Foundations.Propositions. Require Import UniMath.MoreFoundations.Sets. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.DecidablePropositions.