Theorem: VitaliFamily.ae_tendsto_measure_inter_div
File: Mathlib/MeasureTheory/Covering/Differentiation.lean

Proof steps:
state_before: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
⊢ ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
state_after: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
⊢ ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
tactic: let t := toMeasurable μ s
state_before: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
⊢ ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
state_after: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
⊢ ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
tactic: have A :
    ∀ᵐ x ∂μ.restrict s,
      Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x)) := by
    apply ae_mono restrict_le_self
    apply ae_tendsto_measure_inter_div_of_measurableSet
    exact measurableSet_toMeasurable _ _
state_before: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
⊢ ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
state_after: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
⊢ ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
tactic: have B : ∀ᵐ x ∂μ.restrict s, t.indicator 1 x = (1 : ℝ≥0∞) := by
    refine ae_restrict_of_ae_restrict_of_subset (subset_toMeasurable μ s) ?_
    filter_upwards [ae_restrict_mem (measurableSet_toMeasurable μ s)] with _ hx
    simp only [hx, Pi.one_apply, indicator_of_mem]
state_before: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
⊢ ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
state_after: case h
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
h'x : t.indicator 1 x = 1
⊢ Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
tactic: filter_upwards [A, B] with x hx h'x
state_before: case h
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
h'x : t.indicator 1 x = 1
⊢ Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
state_after: case h
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
⊢ Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
tactic: rw [h'x] at hx
state_before: case h
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
⊢ Tendsto (fun a => μ (s ∩ a) / μ a) (v.filterAt x) (𝓝 1)
state_after: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
⊢ (fun a => μ (t ∩ a) / μ a) =ᶠ[v.filterAt x] fun a => μ (s ∩ a) / μ a
tactic: apply hx.congr' _
state_before: α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
⊢ (fun a => μ (t ∩ a) / μ a) =ᶠ[v.filterAt x] fun a => μ (s ∩ a) / μ a
state_after: case h
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
a✝ : Set α
ha : MeasurableSet a✝
⊢ μ (t ∩ a✝) / μ a✝ = μ (s ∩ a✝) / μ a✝
tactic: filter_upwards [v.eventually_filterAt_measurableSet x] with _ ha
state_before: case h
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
a✝ : Set α
ha : MeasurableSet a✝
⊢ μ (t ∩ a✝) / μ a✝ = μ (s ∩ a✝) / μ a✝
state_after: case h.e_a
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
a✝ : Set α
ha : MeasurableSet a✝
⊢ μ (t ∩ a✝) = μ (s ∩ a✝)
tactic: congr 1
state_before: case h.e_a
α : Type u_1
inst✝⁵ : MetricSpace α
m0 : MeasurableSpace α
μ : Measure α
v : VitaliFamily μ
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : SecondCountableTopology α
inst✝² : BorelSpace α
inst✝¹ : IsLocallyFiniteMeasure μ
ρ : Measure α
inst✝ : IsLocallyFiniteMeasure ρ
s : Set α
t : Set α := toMeasurable μ s
A : ∀ᵐ (x : α) ∂μ.restrict s, Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 (t.indicator 1 x))
B : ∀ᵐ (x : α) ∂μ.restrict s, t.indicator 1 x = 1
x : α
hx : Tendsto (fun a => μ (t ∩ a) / μ a) (v.filterAt x) (𝓝 1)
h'x : t.indicator 1 x = 1
a✝ : Set α
ha : MeasurableSet a✝
⊢ μ (t ∩ a✝) = μ (s ∩ a✝)
state_after: no goals
tactic: exact measure_toMeasurable_inter_of_sFinite ha _