(** Composed operations *)
Section Operations_fct.
Context {K : AbsRing} {U V : NormedModule K}.

Lemma ex_filterdiff_scal_l_fct : forall {F} {FF : Filter F} (x : V) (f : U -> K),
ex_filterdiff f F ->
ex_filterdiff (fun u => scal (f u) x) F.