proposition: Lemma mem_max_normed A X : X \in |/|*(A; pi) -> pi.-group X /\ A \subset 'N(X).
proof: Proof. by rewrite inE; move/maxgroupp; move/andP. Qed.
imports: HB(structures) mathcomp.ssreflect.ssreflect mathcomp(ssrbool ssrfun eqtype ssrnat seq div choice fintype bigop) mathcomp(finset prime fingroup morphism automorphism action quotient) mathcomp(gfunctor cyclic pgroup center commutator gseries nilpotent) mathcomp(sylow abelian maximal hall) odd_order(BGsection1 BGsection6)