Section Op_LinearFct.
Context {K : AbsRing} {V : NormedModule K}.

(** [fun x => scal k x] is a linear function if [mult] is commutative *)
Lemma is_linear_scal_r (k : K) :
(forall n m : K, mult n m = mult m n)
-> is_linear (fun x : V => scal k x).