Definition unit_lattice : lattice unitset. Proof. use make_lattice. - exact (λ _ _, tt). - exact (λ _ _, tt). - abstract (repeat split ; intro ; intros ; apply isapropunit). Defined.
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.