theorem LO.Modal.Hilbert.KB_weakerThan_KDB {α : Type u_1} : LO.Modal.Hilbert.KB α ≤ₛ LO.Modal.Hilbert.KDB α

theorem LO.Modal.Hilbert.KB_strictlyWeakerThan_KDB : LO.Modal.Hilbert.KB ℕ <ₛ LO.Modal.Hilbert.KDB ℕ