intuition.
eapply leRat_trans.
eapply expRat_le.
case_eq (bleRat r 1); intuition.
exfalso.
eapply H0.
eapply bleRat_total.
trivial.
eauto.
trivial.
Qed.

(* Specifications: *)
Lemma ratSubtract_sum_1 : forall r1 r2,
~ r1 <= r2 ->
r2 + (ratSubtract r1 r2) == r1.