Definition MapsTo (k:key)(e:elt):= InA eqke (k,e).Definition In k m := exists e:elt, MapsTo k e m.Notation Sort := (sort ltk).Notation Inf := (lelistA ltk).

Lemma Sort_In_cons_3 : forall x l k e, Sort ((k,e)::l) -> In x l -> ~eq x k.