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_Inf_In : forall l p q, Sort l -> Inf q l -> InA eqk p l -> ltk q p.