proposition: Lemma disjoint_app_2 : forall A B (E F : list (asn A B)) (G : list (asn A B)), disjoint (E ++ F) G -> disjoint F G.
proof: Proof. intros. unfold disjoint in *. simpl_asnlist in *. fsetdec. Qed.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.LibTactics Metalib.MetatheoryAtom Metalib.LibTactics