Section Comp.
Context {K : AbsRing} {V : NormedModule K}.
End Comp.
(** * Mean value theorem *)

Lemma bounded_variation (h dh : R -> R) (D : R) (x y : R) :
(forall t : R, Rabs (t - x) <= Rabs (y - x) -> is_derive h t (dh t) /\ (Rabs (dh t) <= D)) ->
Rabs (h y - h x) <= D * Rabs (y - x).