∀ {α : Type u_2} {m0 : MeasurableSpace α} {μ ν : MeasureTheory.Measure α} {S T : Set (Set α)},
  m0 = MeasurableSpace.generateFrom S →
    IsPiSystem S → T ⊆ S → T.Countable → ⋃₀ T = Set.univ → (∀ s ∈ T, μ s ≠ ⊤) → (∀ s ∈ S, μ s = ν s) → μ = ν