proposition: Lemma binds_one_1 : binds x a (one (VarAsn B y b)) -> x = y.
proof: Proof. clear. intros H1. inversion H1 as [HEq | HIn]. inversion HEq; intuition. intuition. Qed.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.LibTactics Metalib.MetatheoryAtom Metalib.LibTactics