exact (ring_dist_l_prf R).
Qed.
Hint Resolve RING_assoc RING_comp RING_unit_r RING_unit_l RING_dist_r
RING_dist_l: algebra.

(* Specifications: *)
Lemma RING_absorbant_r :
forall x : R, Equal (ring_mult x (monoid_unit R)) (monoid_unit R).