proposition: Lemma qact_dom_doms (H : {group rT}) : H \subset D -> qact_dom to H \subset A.
proof: Proof. by move=> sHD; apply/subsetP=> x; rewrite qact_domE // inE; case/andP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype bigop finset fingroup morphism) mathcomp(automorphism quotient action gseries)