proposition: Lemma mulGid : (G : {set gT}) * G = G.
proof: Proof. by apply/eqP; rewrite eqEsubset mulG_subr andbT; case/andP: (valP G). Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)