∀ {X : Type u_1} [m : MeasurableSpace X] {μ : MeasureTheory.Measure X} {𝒜 : Set (Set X)},
  μ.MeasureDense 𝒜 →
    ∀ {s : Set X}, MeasurableSet s → μ s ≠ ⊤ → ∀ (ε : ℝ), 0 < ε → ∃ t ∈ 𝒜, μ t ≠ ⊤ ∧ μ (symmDiff s t) < ENNReal.ofReal ε