∀ {R : Type u_1} {M : Type u_2} [inst : CommRing R] [inst_1 : TopologicalSpace R] [inst_2 : AddCommGroup M]
  [inst_3 : Module R M] (self : ModuleFilterBasis R M) {U : Set M},
  U ∈ self.sets → ∃ V ∈ nhds 0, ∃ W ∈ self.sets, V • W ⊆ U