proposition: Lemma maxainvS : maxainv K N -> N \subset K.
proof: Proof. by move=> pNN; rewrite proper_sub // maxainv_proper. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype bigop finset fingroup morphism) mathcomp(automorphism quotient action gseries)