fact: Definition errloc (a : 'rV[F]_n) (E : {set 'I_n}) : {poly F} := \prod_(i in E) (1 - a ``_ i *: 'X).
imports: mathcomp(all_ssreflect ssralg finalg poly polydiv cyclic) mathcomp(perm matrix mxpoly) ssr_ext ssralg_ext cyclic_code dft