proposition: Lemma uniq_map : uniq (map f1 f2 E) <-> uniq E.
proof: Proof. clear. intuition eauto using uniq_map_1, uniq_map_2. Qed.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.LibTactics Metalib.MetatheoryAtom Metalib.LibTactics