∀ {G : Type u_1} [inst : Group G] {S : Type u_3} {H : Type u_4} [inst_1 : Group H] [inst_2 : SetLike S H]
  [SubgroupClass S H] {s : S} [inst_4 : MulAction G H] [IsScalarTower G H H], MulAction.IsBlock G ↑s