proposition: Lemma normJ A x : 'N(A :^ x) = 'N(A) :^ x.
proof: Proof. by apply/setP=> y; rewrite mem_conjg !inE -conjsgM conjgCV conjsgM conjSg. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)