fact: Definition syndrome r (y : 'rV_n) : 'rV[F]_r := \row_i (syndrome_coord i y).
imports: mathcomp(all_ssreflect ssralg finalg poly polydiv cyclic) mathcomp(perm matrix mxpoly vector mxalgebra zmodp) ssr_ext ssralg_ext vandermonde linearcode dft poly_decoding