Proposition isaprop_regular_epi_chosen_pb_stable {C : category} (PB : Pullbacks C) : isaprop (regular_epi_chosen_pb_stable PB). Proof. do 6 (use impred ; intro). apply isaprop_is_regular_epi. Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Prelude. Require Import UniMath.CategoryTheory.Limits.Coequalizers. Require Import UniMath.CategoryTheory.Limits.Pullbacks. Require Import UniMath.CategoryTheory.Epis.