(** ** Composition *)
Section Comp.
Context {V : CompleteNormedModule R_AbsRing}.
(* Notation consistent version of the lemmas used in is_RInt_comp *)

Lemma is_RInt_comp (f : R -> V) (g dg : R -> R) (a b : R) :
(forall x, Rmin a b <= x <= Rmax a b -> continuous f (g x)) ->
(forall x, Rmin a b <= x <= Rmax a b -> is_derive g x (dg x) /\ continuous dg x) ->
is_RInt (fun y => scal (dg y) (f (g y))) a b (RInt f (g a) (g b)).