proposition: Lemma rel_map_in : forall (A B : Type)(lsa : list A)(lsb : list B) rel, rel_map rel lsa lsb -> (forall a b1 b2, In a lsa -> rel a b1 -> rel a b2 -> b1 = b2) -> forall b a, In a lsa -> rel a b -> In b lsb.
proof: Proof. induction 1; intuition; simpl in *. intuition; subst. left; eauto. right; eauto. Qed.
imports: FCF.Rat List Permutation Arith FCF.EqDec FCF.StdNat Bool Permutation