fact: Definition erreval (b a : 'rV[F]_n) e := \sum_(i in supp e) e ``_ i * b ``_ i *: \sigma_(a, e, i).
imports: mathcomp(all_ssreflect ssralg finalg poly polydiv cyclic) mathcomp(perm matrix mxpoly) ssr_ext ssralg_ext cyclic_code dft