fact: Definition DIS : 'M[F]_(k, n) := castmx (erefl, subnKC dimlen) (row_mx 1%:M 0).
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