proposition: Lemma disjoint_app_l : forall A B (E F : list (asn A B)) (G : list (asn A B)), disjoint (E ++ F) G <-> disjoint E G /\ disjoint F G.
proof: Proof. intros; intuition eauto using disjoint_app_1, disjoint_app_2, disjoint_app_3. Qed.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.LibTactics Metalib.MetatheoryAtom Metalib.LibTactics