fact: Definition GRS_PCM_sq (a b : 'rV[F]_n) r := \matrix_(i < r, j < r) (GRS.PCM a b r) i (inord j).
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