(** *** Order *)

Lemma filterlim_le_le :
forall {T F} {FF : Filter F} (f g h : T -> R) (l : Rbar),
F (fun x => f x <= g x <= h x) ->
filterlim f F (Rbar_locally l) ->
filterlim h F (Rbar_locally l) ->
filterlim g F (Rbar_locally l).