fact: Axiom binds_In_inv : forall x (E : list (atom*A)), In x (dom E) -> exists a, binds x a E.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.AssocList Metalib.MetatheoryAtom Metalib.LibTactics