proposition: Lemma uniq_app_iff : uniq (E ++ F) <-> uniq E /\ uniq F /\ disjoint E F.
proof: Proof. clear; intuition auto using uniq_app_1, uniq_app_2, uniq_app_3, uniq_app_4. Qed.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Coq.Strings.String String Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.LibTactics Metalib.CoqFSetInterface Coq.Classes.Equivalence Coq.Classes.EquivDec Metalib.CoqEqDec