proposition: Lemma cent1J x y : 'C[x ^ y] = 'C[x] :^ y.
proof: Proof. by rewrite -conjg_set1 normJ. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)