proposition: Lemma centI A B : 'C(A) <*> 'C(B) \subset 'C(A :&: B).
proof: Proof. by rewrite gen_subG subUset !centS ?(subsetIl, subsetIr). Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)