proposition: Lemma ratDistance_add_same_l_gen : forall r1 r2 r3 r4, r1 == r3 -> ratDistance (r1 + r2) (r3 + r4) == ratDistance r2 r4.
proof: Proof. intuition. rewrite H. eapply ratDistance_add_same_l. Qed.
imports: micromega.Lia List FCF.StdNat Arith Lia Setoid RelationClasses Coq.Classes.Morphisms