proposition: Lemma Prod1 l : l != Blank -> Prod [:: l] = l.
proof: Proof. by case/letterP : l. Qed.
imports: mathcomp(all_ssreflect ssralg fingroup finalg perm zmodp) mathcomp(matrix) ssr_ext ssralg_ext num_occ f2 ssrR hamming tanner linearcode