proposition: Lemma centvX V u n : u \in 'C(V)%VS -> u ^+ n \in 'C(V)%VS.
proof: Proof. by move/centvP=> cVu; apply/centvP=> v /cVu/esym/commrX->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype div tuple finfun bigop ssralg) mathcomp(finalg zmodp matrix vector poly)