(** Swapping bounds *)

(* Specifications: *)
Lemma is_RInt_swap :
forall (f : R -> V) (a b : R) (If : V),
is_RInt f b a If -> is_RInt f a b (opp If).
Lemma ex_RInt_swap :
forall (f : R -> V) (a b : R),
ex_RInt f a b -> ex_RInt f b a.