proposition: Lemma degU k z : deg << k *g z >> = k.
proof: Proof. by rewrite /deg liftU /GRing.scale /= mulr1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order generic_quotient) mathcomp(ssralg ssrnum ssrint)