Proposition isaset_regular_element (H : complete_heyting_algebra) : isaset (regular_element H). Proof. use isaset_total2 ; [ apply setproperty | ]. intro x. apply isasetaprop. apply propproperty. Qed.
Require Import UniMath.MoreFoundations.All. Require Import UniMath.Algebra.BinaryOperations. Require Import UniMath.OrderTheory.Lattice.Lattice. Require Import UniMath.OrderTheory.Lattice.Bounded. Require Import UniMath.OrderTheory.Lattice.Heyting. Require Import UniMath.OrderTheory.Lattice.CompleteHeyting. Require Import UniMath.OrderTheory.Lattice.DerivedLawsCompleteHeyting.