proposition: Lemma fgscale1r D : 1 *:F D = D.
proof: Proof. by apply/eqP/freeg_eqP=> x; rewrite !coeff_fgscale mul1r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order generic_quotient) mathcomp(ssralg ssrnum ssrint)