Theorem: MeasureTheory.measure_isClosed_eq_of_forall_lintegral_eq_of_isFiniteMeasure
File: Mathlib/MeasureTheory/Measure/HasOuterApproxClosed.lean

Proof steps:
state_before: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
⊢ μ F = ν F
state_after: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
⊢ μ F = ν F
tactic: have ν_finite : IsFiniteMeasure ν := by
    constructor
    have whole := h 1
    simp only [BoundedContinuousFunction.coe_one, Pi.one_apply, ENNReal.coe_one, lintegral_const,
      one_mul] at whole
    simpa [← whole] using IsFiniteMeasure.measure_univ_lt_top
state_before: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
⊢ μ F = ν F
state_after: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
obs_μ : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂μ) atTop (𝓝 (μ F))
⊢ μ F = ν F
tactic: have obs_μ := HasOuterApproxClosed.tendsto_lintegral_apprSeq F_closed μ
state_before: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
obs_μ : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂μ) atTop (𝓝 (μ F))
⊢ μ F = ν F
state_after: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
obs_μ : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂μ) atTop (𝓝 (μ F))
obs_ν : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂ν) atTop (𝓝 (ν F))
⊢ μ F = ν F
tactic: have obs_ν := HasOuterApproxClosed.tendsto_lintegral_apprSeq F_closed ν
state_before: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
obs_μ : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂μ) atTop (𝓝 (μ F))
obs_ν : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂ν) atTop (𝓝 (ν F))
⊢ μ F = ν F
state_after: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
obs_ν : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂ν) atTop (𝓝 (ν F))
obs_μ : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂ν) atTop (𝓝 (μ F))
⊢ μ F = ν F
tactic: simp_rw [h] at obs_μ
state_before: Ω : Type u_1
inst✝⁴ : MeasurableSpace Ω
inst✝³ : TopologicalSpace Ω
inst✝² : HasOuterApproxClosed Ω
inst✝¹ : OpensMeasurableSpace Ω
μ ν : Measure Ω
inst✝ : IsFiniteMeasure μ
h : ∀ (f : Ω →ᵇ ℝ≥0), ∫⁻ (x : Ω), ↑(f x) ∂μ = ∫⁻ (x : Ω), ↑(f x) ∂ν
F : Set Ω
F_closed : IsClosed F
ν_finite : IsFiniteMeasure ν
obs_ν : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂ν) atTop (𝓝 (ν F))
obs_μ : Tendsto (fun n => ∫⁻ (x : Ω), ↑((F_closed.apprSeq n) x) ∂ν) atTop (𝓝 (μ F))
⊢ μ F = ν F
state_after: no goals
tactic: exact tendsto_nhds_unique obs_μ obs_ν