proposition: Lemma cc_cm_proof : is_CMonoid cc_csemi_grp cc_zero.
proof: Proof. apply Build_is_CMonoid. unfold is_rht_unit in |- *. intros. elim x. intros. simpl in |- *. unfold cc_eq in |- *. simpl in |- *. split; algebra. unfold is_lft_unit in |- *. intros. elim x. intros. simpl in |- *. unfold cc_eq in |- *. simpl in |- *. split; algebra. Qed.
imports: CoRN.reals.NRootIR