(** Uniform convergence *)
Definition CVU (fn:nat -> R -> R) (f:R -> R) (x:R)
  (r:posreal) : Prop :=
  forall eps:R,
    0 < eps ->
    exists N : nat,
      (forall (n:nat) (y:R),
        (N <= n)%nat -> Boule x r y -> Rabs (f y - fn n y) < eps).(** Normal convergence *)
Definition CVN_r (fn:nat -> R -> R) (r:posreal) : Type :=
  { An:nat -> R &
    { l:R |
      Un_cv (fun n:nat => sum_f_R0 (fun k:nat => Rabs (An k)) n) l /\
      (forall (n:nat) (y:R), Boule 0 r y -> Rabs (fn n y) <= An n) } }.Definition CVN_R (fn:nat -> R -> R) : Type := forall r:posreal, CVN_r fn r.Definition SFL (fn:nat -> R -> R)
  (cv:forall x:R, { l:R | Un_cv (fun N:nat => SP fn N x) l })
  (y:R) : R := let (a,_) := cv y in a.

Lemma CVU_derivable : forall f f' g g' c d, CVU f' g' c d -> (forall x, Boule c d x -> Un_cv (fun n => f n x) (g x)) -> (forall n x, Boule c d x -> derivable_pt_lim (f n) x (f' n x)) -> forall x, Boule c d x -> derivable_pt_lim g x (g' x).