Proposition cha_not_top (H : complete_heyting_algebra) : ¬ ⊤ = (⊥ : H). Proof. cbn. use cha_le_antisymm. - rewrite <- (cha_runit_min_bot (¬ ⊤)). use cha_exp_eval. - use cha_to_le_exp. use cha_min_le_l. 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.