Definition tightap_aprel {X : UU} (ap : tightap X) : aprel X := pr1 ap ,, (pr1 (pr2 ap)).
Require Import UniMath.Foundations.Propositions. Require Import UniMath.MoreFoundations.Sets. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.DecidablePropositions.