proposition: Lemma uniq_app_4 : uniq E -> uniq F -> disjoint E F -> uniq (E ++ F).
proof: Proof. clear. intros HE HF Hd. induction E as [ | a E']; simpl_asnlist in *. assumption. rewrite -> disjoint_app_l in Hd. inversion HE; subst. apply uniq_push. intuition. rewrite disjoint_one_l in Hd. simpl_asnlist. fsetdec. apply uniq_alt. inversion HE; subst. intuition. Qed.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.LibTactics Metalib.MetatheoryAtom Metalib.LibTactics