proposition: Lemma R_is_Group : is_CGroup RMonoid RNeg_op.
proof: Proof. unfold is_CGroup. intro x. unfold is_inverse. split. apply Rplus_opp_r. apply Rplus_opp_l. Qed.
imports: CoRN.algebra.CSetoids CoRN.algebra.CSemiGroups CoRN.algebra.CMonoids CoRN.algebra.CGroups CoRN.tactics.CornTac CoRN.algebra.CAbGroups CoRN.algebra.CRings CoRN.algebra.CFields CoRN.algebra.COrdFields CoRN.reals.CReals Coq.Reals.RIneq Coq.Reals.Rcomplete Coq.Reals.Rlimit Coq.Reals.Rbasic_fun Coq(Lra)