intuition.
eapply H.
specialize (ratMult_0 r1 r2); intuition.
eapply H.
specialize (ratMult_0 r1 r2); intuition.
apply ratMult_0 in H0.
intuition.
Qed.

(* Specifications: *)
Theorem leRat_num : forall n1 n2 d,
le n1 n2 ->
leRat (RatIntro n1 d) (RatIntro n2 d).