(* For consistency with Rplus_opp_r and Rplus_opp_l. *)
Definition Rmult_inv_r := Rinv_r.Definition Rmult_inv_l := Rinv_l.

Lemma Rplus_minus_assoc : forall r1 r2 r3, r1 + (r2 - r3) = (r1 + r2) - r3.