Corollary and_mone_l: forall x, and mone x = x.

(* Specifications: *)
Theorem and_idem: forall x, and x x = x.
Theorem or_commut: forall x y, or x y = or y x.
Theorem or_assoc: forall x y z, or (or x y) z = or x (or y z).
Theorem or_zero: forall x, or x zero = x.