proposition: Lemma cent1vP u v : reflect (u * v = v * u) (u \in 'C[v]%VS).
proof: Proof. by rewrite (sameP eqlfunP eqP) !lfunE /=; apply: eqP. 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)