fact: Definition binds (x : atom) (a : A) (E : list (asn A B)) : Prop := List.In (VarAsn B x a) E.
imports: Coq.FSets.FSets Coq.Lists.List Coq.Logic.Decidable Metalib.CoqFSetDecide Metalib.CoqListFacts Metalib.LibTactics Metalib.MetatheoryAtom Metalib.LibTactics