Definition RInt_gen (f : R -> V) (a b : (R -> Prop) -> Prop) :=
  iota (is_RInt_gen f a b).

Lemma RInt_gen_norm {Fa Fb : (R -> Prop) -> Prop} {FFa : ProperFilter Fa} {FFb : ProperFilter Fb} (f : R -> V) (g : R -> R) (lf : V) (lg : R) : filter_prod Fa Fb (fun ab => fst ab <= snd ab) -> filter_prod Fa Fb (fun ab => forall x, fst ab <= x <= snd ab -> norm (f x) <= g x) -> is_RInt_gen f Fa Fb lf -> is_RInt_gen g Fa Fb lg -> norm lf <= lg.