proposition: Lemma mem_wH_supp x (i : 'I_n) : (x ``_ i != 0) = (i \in wH_supp x).
proof: Proof. by rewrite inE. Qed.
imports: Reals mathcomp(all_ssreflect fingroup zmodp ssralg finalg perm matrix) mathcomp(poly mxalgebra mxpoly) mathcomp(Rstruct) ssr_ext ssralg_ext f2 num_occ natbin ssrR Reals_ext bigop_ext