proposition: Theorem mul_shuffle0 : ∀ n m p, n * m * p = n * p * m.
proof: Proof. intros n m p. destruct n as [n| ]; [ simpl | reflexivity ]. destruct m as [m| ]; [ simpl | destruct p; reflexivity ]. destruct p as [p| ]; [ simpl | reflexivity ]. rewrite Nat.mul_shuffle0; reflexivity. Qed.
imports: Utf8 Compare_dec NPeano Misc