Proposition isaprop_is_effective {C : univalent_category} {x : C} (R : internal_eqrel x) : isaprop (is_effective R). Proof. use isaproptotal2. - intro. apply isaprop_isPullback. - intros. apply isaprop_Coequalizer. apply univalent_category_is_univalent. Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Prelude. Require Import UniMath.CategoryTheory.Limits.Pullbacks. Require Import UniMath.CategoryTheory.Limits.Coequalizers. Require Import UniMath.CategoryTheory.RegularAndExact.RegularCategory.