Hint Resolve add_const_to_CR : Recurrence.
Hint Rewrite @add_const_to_CR : Recurrence.

(* Specifications: *)
(** Lemma 17 *)
Lemma mul_const_to_CR:
forall `{Ring R} (r c0: R) (cr: CR) (n: nat),
r * ((recurCR c0 mult cr) # n) =
((recurCR (c0 * r) mult cr) # n).