(* RsumOver *)

Definition RsumOver (X: Set) (l: list X) (f: X -> R): R := Rsum (map f l).

Lemma RsumOver_concat_map (X Y: Set) (f: X -> R) (g: Y -> list X) (l: list Y): RsumOver (concat (map g l)) f = RsumOver l (fun x => RsumOver (g x) f).