fact: Definition goppa_code_condition := size g = (n - k).+1.
imports: mathcomp(all_ssreflect ssralg finalg poly polydiv) mathcomp(cyclic perm matrix mxpoly vector mxalgebra zmodp) mathcomp(finfield falgebra fieldext) ssr_ext ssralg_ext vandermonde linearcode dft poly_decoding grs bch