theorem LO.Modal.Hilbert.K4_weakerThan_K45 {α : Type u_1} : LO.Modal.Hilbert.K4 α ≤ₛ LO.Modal.Hilbert.K45 α

theorem LO.Modal.Hilbert.K4_strictlyWeakerThan_K45 : LO.Modal.Hilbert.K4 ℕ <ₛ LO.Modal.Hilbert.K45 ℕ