proposition: Lemma oclosed : oppr_closed C.
proof: Proof. move=> ? ?; by rewrite -scaleN1r rpredZ. Qed.
imports: mathcomp(all_ssreflect ssralg poly polydiv fingroup perm) mathcomp(finalg zmodp matrix mxalgebra mxpoly vector) ssr_ext ssralg_ext poly_ext f2 hamming decoding channel_code