proposition: Lemma uniq_app_3 : uniq (E ++ F) -> disjoint E F.
proof: Proof. clear. intros J. unfold disjoint. alist induction E as [ | ? ? ? IH ]. fsetdec. inversion J; subst. simpl_alist in *. lapply IH. fsetdec. auto. 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