fact: Definition PCM : 'M_(t, n) := \matrix_(i < t, j < n) (a ``_ j) ^+ i.*2.+1.
imports: mathcomp(all_ssreflect ssralg poly polydiv finalg zmodp) mathcomp(matrix mxalgebra mxpoly vector fieldext finfield) ssralg_ext hamming linearcode decoding cyclic_code poly_decoding vandermonde dft euclid grs f2