proposition: Lemma vssub_is_multiplicative : multiplicative (vssub kK).
proof: Proof. split => [v w|]; apply/val_inj => /=; last first. by rewrite vsprojK ?algid1 ?rmorph1 ?rpred1//. by rewrite /= !vsprojK/= ?rpredM//= (subvP kK _ (subvsP _)) . Qed.
imports: HB(structures) mathcomp(all_ssreflect all_fingroup all_algebra all_solvable) mathcomp(all_field)