∀ {X : Type u_1} [inst : TopologicalSpace X] [T2Space X] [LocallyCompactSpace X] [inst_3 : MeasurableSpace X]
  [BorelSpace X] {μ ν : MeasureTheory.Measure X} [μ.Regular] [ν.Regular],
  (∀ (f : CompactlySupportedContinuousMap X NNReal), ∫ (x : X), ↑(f x) ∂μ = ∫ (x : X), ↑(f x) ∂ν) → μ = ν