Theorem: MeasureTheory.tendstoUniformlyOn_of_ae_tendsto'
File: Mathlib/MeasureTheory/Function/Egorov.lean

Proof steps:
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
inst✝⁵ : MetricSpace β
μ : Measure α
inst✝⁴ : SemilatticeSup ι
inst✝³ : Nonempty ι
inst✝² : Countable ι
γ : Type u_4
inst✝¹ : TopologicalSpace γ
f : ι → α → β
g : α → β
s : Set α
inst✝ : IsFiniteMeasure μ
hf : ∀ (n : ι), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n => f n x) atTop (𝓝 (g x))
ε : ℝ
hε : 0 < ε
⊢ ∃ t, MeasurableSet t ∧ μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop tᶜ
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
inst✝⁵ : MetricSpace β
μ : Measure α
inst✝⁴ : SemilatticeSup ι
inst✝³ : Nonempty ι
inst✝² : Countable ι
γ : Type u_4
inst✝¹ : TopologicalSpace γ
f : ι → α → β
g : α → β
s : Set α
inst✝ : IsFiniteMeasure μ
hf : ∀ (n : ι), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n => f n x) atTop (𝓝 (g x))
ε : ℝ
hε : 0 < ε
t : Set α
left✝ : t ⊆ univ
ht : MeasurableSet t
htendsto : μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop (univ \ t)
⊢ ∃ t, MeasurableSet t ∧ μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop tᶜ
tactic: have ⟨t, _, ht, htendsto⟩ := tendstoUniformlyOn_of_ae_tendsto hf hg MeasurableSet.univ
    (measure_ne_top μ Set.univ) (by filter_upwards [hfg] with _ htendsto _ using htendsto) hε
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
inst✝⁵ : MetricSpace β
μ : Measure α
inst✝⁴ : SemilatticeSup ι
inst✝³ : Nonempty ι
inst✝² : Countable ι
γ : Type u_4
inst✝¹ : TopologicalSpace γ
f : ι → α → β
g : α → β
s : Set α
inst✝ : IsFiniteMeasure μ
hf : ∀ (n : ι), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n => f n x) atTop (𝓝 (g x))
ε : ℝ
hε : 0 < ε
t : Set α
left✝ : t ⊆ univ
ht : MeasurableSet t
htendsto : μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop (univ \ t)
⊢ ∃ t, MeasurableSet t ∧ μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop tᶜ
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
inst✝⁵ : MetricSpace β
μ : Measure α
inst✝⁴ : SemilatticeSup ι
inst✝³ : Nonempty ι
inst✝² : Countable ι
γ : Type u_4
inst✝¹ : TopologicalSpace γ
f : ι → α → β
g : α → β
s : Set α
inst✝ : IsFiniteMeasure μ
hf : ∀ (n : ι), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n => f n x) atTop (𝓝 (g x))
ε : ℝ
hε : 0 < ε
t : Set α
left✝ : t ⊆ univ
ht : MeasurableSet t
htendsto : μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop (univ \ t)
⊢ μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop tᶜ
tactic: refine ⟨_, ht, ?_⟩
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
inst✝⁵ : MetricSpace β
μ : Measure α
inst✝⁴ : SemilatticeSup ι
inst✝³ : Nonempty ι
inst✝² : Countable ι
γ : Type u_4
inst✝¹ : TopologicalSpace γ
f : ι → α → β
g : α → β
s : Set α
inst✝ : IsFiniteMeasure μ
hf : ∀ (n : ι), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n => f n x) atTop (𝓝 (g x))
ε : ℝ
hε : 0 < ε
t : Set α
left✝ : t ⊆ univ
ht : MeasurableSet t
htendsto : μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop (univ \ t)
⊢ μ t ≤ ENNReal.ofReal ε ∧ TendstoUniformlyOn f g atTop tᶜ
state_after: no goals
tactic: rwa [Set.compl_eq_univ_diff]