Section Properties3.
Context {K : AbsRing} {V : NormedModule K}.
exact is_series_scal.
Qed.
exact ex_series_scal.
Qed.
End Properties3.

Lemma ex_series_scal_r (c : R) (a : nat -> R) :
ex_series  a -> ex_series  (fun n => a n * c).