intros n m p H H1;
apply Z.le_ge; apply Zmult_le_neg_compat_l_rev with p; auto with zarith.
Qed.

(* Specifications: *)
Theorem Zmult_gt_compat_l_rev:
forall n m p : Z, (p > 0)%Z -> (p * n > p * m)%Z -> (n > m)%Z.