proposition: Lemma fgnormE D : fgnorm D = \sum_(z <- dom D) << `|coeff z D| *g z >>.
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order generic_quotient) mathcomp(ssralg ssrnum ssrint)