Canonical C_AbelianGroup :=
AbelianGroup.Pack C C_AbelianGroup_mixin C.

Lemma Copp_0 : Copp 0 = 0.
Definition C_Ring_mixin :=
Ring.Mixin _ _ _ Cmult_assoc Cmult_1_r Cmult_1_l Cmult_plus_distr_r Cmult_plus_distr_l.