l3lab/ntp-mathlib huggingface dataset:
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    

Proof state:
case intro.intro
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
g : β →ₛ E
hg : snorm (f' - ↑g) p μ < ε
g_mem : Memℒp (↑g) p
⊢ snorm (f - ↑g) p μ = snorm (f' - ↑g) p μ

Next tactic:
apply snorm_congr_ae
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    

Proof state:
case intro.intro.hfg
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
g : β →ₛ E
hg : snorm (f' - ↑g) p μ < ε
g_mem : Memℒp (↑g) p
⊢ f - ↑g =ᵐ[μ] f' - ↑g

Next tactic:
filter_upwards [hf.1.ae_eq_mk] with x hx
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    filter_upwards [hf.1.ae_eq_mk] with x hx
    

Proof state:
case h
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
g : β →ₛ E
hg : snorm (f' - ↑g) p μ < ε
g_mem : Memℒp (↑g) p
x : β
hx : f x = AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ) x
⊢ (f - ↑g) x = (f' - ↑g) x

Next tactic:
simpa only [Pi.sub_apply, sub_left_inj] using hx
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    filter_upwards [hf.1.ae_eq_mk] with x hx
    simpa only [Pi.sub_apply, sub_left_inj] using hx
  

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
⊢ ∃ g, snorm (f' - ↑g) p μ < ε ∧ Memℒp (↑g) p

Next tactic:
have hf' : Memℒp f' p μ := hf.ae_eq hf.1.ae_eq_mk
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    filter_upwards [hf.1.ae_eq_mk] with x hx
    simpa only [Pi.sub_apply, sub_left_inj] using hx
  have hf' : Memℒp f' p μ := hf.ae_eq hf.1.ae_eq_mk
  

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
hf' : Memℒp f' p
⊢ ∃ g, snorm (f' - ↑g) p μ < ε ∧ Memℒp (↑g) p

Next tactic:
have f'meas : Measurable f' := hf.1.measurable_mk
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    filter_upwards [hf.1.ae_eq_mk] with x hx
    simpa only [Pi.sub_apply, sub_left_inj] using hx
  have hf' : Memℒp f' p μ := hf.ae_eq hf.1.ae_eq_mk
  have f'meas : Measurable f' := hf.1.measurable_mk
  

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
hf' : Memℒp f' p
f'meas : Measurable f'
⊢ ∃ g, snorm (f' - ↑g) p μ < ε ∧ Memℒp (↑g) p

Next tactic:
have : SeparableSpace (range f' ∪ {0} : Set E) :=
    StronglyMeasurable.separableSpace_range_union_singleton hf.1.stronglyMeasurable_mk
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    filter_upwards [hf.1.ae_eq_mk] with x hx
    simpa only [Pi.sub_apply, sub_left_inj] using hx
  have hf' : Memℒp f' p μ := hf.ae_eq hf.1.ae_eq_mk
  have f'meas : Measurable f' := hf.1.measurable_mk
  have : SeparableSpace (range f' ∪ {0} : Set E) :=
    StronglyMeasurable.separableSpace_range_union_singleton hf.1.stronglyMeasurable_mk
  

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
hf' : Memℒp f' p
f'meas : Measurable f'
this : SeparableSpace ↑(Set.range f' ∪ {0})
⊢ ∃ g, snorm (f' - ↑g) p μ < ε ∧ Memℒp (↑g) p

Next tactic:
rcases ((tendsto_approxOn_range_Lp_snorm hp_ne_top f'meas hf'.2).eventually <|
    gt_mem_nhds hε.bot_lt).exists with ⟨n, hn⟩
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    filter_upwards [hf.1.ae_eq_mk] with x hx
    simpa only [Pi.sub_apply, sub_left_inj] using hx
  have hf' : Memℒp f' p μ := hf.ae_eq hf.1.ae_eq_mk
  have f'meas : Measurable f' := hf.1.measurable_mk
  have : SeparableSpace (range f' ∪ {0} : Set E) :=
    StronglyMeasurable.separableSpace_range_union_singleton hf.1.stronglyMeasurable_mk
  rcases ((tendsto_approxOn_range_Lp_snorm hp_ne_top f'meas hf'.2).eventually <|
    gt_mem_nhds hε.bot_lt).exists with ⟨n, hn⟩
  

Proof state:
case intro
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
hf' : Memℒp f' p
f'meas : Measurable f'
this : SeparableSpace ↑(Set.range f' ∪ {0})
n : ℕ
hn : snorm (↑(approxOn f' f'meas (Set.range f' ∪ {0}) 0 (_ : 0 ∈ Set.range f' ∪ {0}) n) - f') p μ < ε
⊢ ∃ g, snorm (f' - ↑g) p μ < ε ∧ Memℒp (↑g) p

Next tactic:
rw [← snorm_neg, neg_sub] at hn
/-- Any function in `ℒp` can be approximated by a simple function if `p < ∞`. -/
theorem _root_.MeasureTheory.Memℒp.exists_simpleFunc_snorm_sub_lt {E : Type*}
    [NormedAddCommGroup E] {f : β → E} {μ : Measure β} (hf : Memℒp f p μ) (hp_ne_top : p ≠ ∞)
    {ε : ℝ≥0∞} (hε : ε ≠ 0) : ∃ g : β →ₛ E, snorm (f - ⇑g) p μ < ε ∧ Memℒp g p μ := by
  borelize E
  let f' := hf.1.mk f
  rsuffices ⟨g, hg, g_mem⟩ : ∃ g : β →ₛ E, snorm (f' - ⇑g) p μ < ε ∧ Memℒp g p μ
  · refine' ⟨g, _, g_mem⟩
    suffices snorm (f - ⇑g) p μ = snorm (f' - ⇑g) p μ by rwa [this]
    apply snorm_congr_ae
    filter_upwards [hf.1.ae_eq_mk] with x hx
    simpa only [Pi.sub_apply, sub_left_inj] using hx
  have hf' : Memℒp f' p μ := hf.ae_eq hf.1.ae_eq_mk
  have f'meas : Measurable f' := hf.1.measurable_mk
  have : SeparableSpace (range f' ∪ {0} : Set E) :=
    StronglyMeasurable.separableSpace_range_union_singleton hf.1.stronglyMeasurable_mk
  rcases ((tendsto_approxOn_range_Lp_snorm hp_ne_top f'meas hf'.2).eventually <|
    gt_mem_nhds hε.bot_lt).exists with ⟨n, hn⟩
  rw [← snorm_neg, neg_sub] at hn
  

Proof state:
case intro
α : Type u_1
β : Type u_2
ι : Type u_3
E✝ : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E✝
inst✝² : NormedAddCommGroup E✝
inst✝¹ : NormedAddCommGroup F
q : ℝ
p : ℝ≥0∞
E : Type u_7
inst✝ : NormedAddCommGroup E
f : β → E
μ : Measure β
hf : Memℒp f p
hp_ne_top : p ≠ ⊤
ε : ℝ≥0∞
hε : ε ≠ 0
this✝¹ : MeasurableSpace E := borel E
this✝ : BorelSpace E
f' : β → E := AEStronglyMeasurable.mk f (_ : AEStronglyMeasurable f μ)
hf' : Memℒp f' p
f'meas : Measurable f'
this : SeparableSpace ↑(Set.range f' ∪ {0})
n : ℕ
hn : snorm (f' - ↑(approxOn f' f'meas (Set.range f' ∪ {0}) 0 (_ : 0 ∈ Set.range f' ∪ {0}) n)) p μ < ε
⊢ ∃ g, snorm (f' - ↑g) p μ < ε ∧ Memℒp (↑g) p

Next tactic:
exact ⟨_, hn, memℒp_approxOn_range f'meas hf' _⟩
theorem tendsto_approxOn_L1_nnnorm [OpensMeasurableSpace E] {f : β → E} (hf : Measurable f)
    {s : Set E} {y₀ : E} (h₀ : y₀ ∈ s) [SeparableSpace s] {μ : Measure β}
    (hμ : ∀ᵐ x ∂μ, f x ∈ closure s) (hi : HasFiniteIntegral (fun x => f x - y₀) μ) :
    Tendsto (fun n => ∫⁻ x, ‖approxOn f hf s y₀ h₀ n x - f x‖₊ ∂μ) atTop (𝓝 0) := by
  

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E
inst✝² : NormedAddCommGroup E
inst✝¹ : OpensMeasurableSpace E
f : β → E
hf : Measurable f
s : Set E
y₀ : E
h₀ : y₀ ∈ s
inst✝ : SeparableSpace ↑s
μ : Measure β
hμ : ∀ᵐ (x : β) ∂μ, f x ∈ closure s
hi : HasFiniteIntegral fun x => f x - y₀
⊢ Tendsto (fun n => ∫⁻ (x : β), ↑‖↑(approxOn f hf s y₀ h₀ n) x - f x‖₊ ∂μ) atTop (𝓝 0)

Next tactic:
simpa [snorm_one_eq_lintegral_nnnorm] using
    tendsto_approxOn_Lp_snorm hf h₀ one_ne_top hμ
      (by simpa [snorm_one_eq_lintegral_nnnorm] using hi)
theorem tendsto_approxOn_L1_nnnorm [OpensMeasurableSpace E] {f : β → E} (hf : Measurable f)
    {s : Set E} {y₀ : E} (h₀ : y₀ ∈ s) [SeparableSpace s] {μ : Measure β}
    (hμ : ∀ᵐ x ∂μ, f x ∈ closure s) (hi : HasFiniteIntegral (fun x => f x - y₀) μ) :
    Tendsto (fun n => ∫⁻ x, ‖approxOn f hf s y₀ h₀ n x - f x‖₊ ∂μ) atTop (𝓝 0) := by
  simpa [snorm_one_eq_lintegral_nnnorm] using
    tendsto_approxOn_Lp_snorm hf h₀ one_ne_top hμ
      (by 

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E
inst✝² : NormedAddCommGroup E
inst✝¹ : OpensMeasurableSpace E
f : β → E
hf : Measurable f
s : Set E
y₀ : E
h₀ : y₀ ∈ s
inst✝ : SeparableSpace ↑s
μ : Measure β
hμ : ∀ᵐ (x : β) ∂μ, f x ∈ closure s
hi : HasFiniteIntegral fun x => f x - y₀
⊢ snorm (fun x => f x - y₀) 1 μ < ⊤

Next tactic:
simpa [snorm_one_eq_lintegral_nnnorm] using hi
theorem integrable_approxOn [BorelSpace E] {f : β → E} {μ : Measure β} (fmeas : Measurable f)
    (hf : Integrable f μ) {s : Set E} {y₀ : E} (h₀ : y₀ ∈ s) [SeparableSpace s]
    (hi₀ : Integrable (fun _ => y₀) μ) (n : ℕ) : Integrable (approxOn f fmeas s y₀ h₀ n) μ := by
  

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E
inst✝² : NormedAddCommGroup E
inst✝¹ : BorelSpace E
f : β → E
μ : Measure β
fmeas : Measurable f
hf : Integrable f
s : Set E
y₀ : E
h₀ : y₀ ∈ s
inst✝ : SeparableSpace ↑s
hi₀ : Integrable fun x => y₀
n : ℕ
⊢ Integrable ↑(approxOn f fmeas s y₀ h₀ n)

Next tactic:
rw [← memℒp_one_iff_integrable] at hf hi₀ ⊢
theorem integrable_approxOn [BorelSpace E] {f : β → E} {μ : Measure β} (fmeas : Measurable f)
    (hf : Integrable f μ) {s : Set E} {y₀ : E} (h₀ : y₀ ∈ s) [SeparableSpace s]
    (hi₀ : Integrable (fun _ => y₀) μ) (n : ℕ) : Integrable (approxOn f fmeas s y₀ h₀ n) μ := by
  rw [← memℒp_one_iff_integrable] at hf hi₀ ⊢
  

Proof state:
α : Type u_1
β : Type u_2
ι : Type u_3
E : Type u_4
F : Type u_5
𝕜 : Type u_6
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace E
inst✝² : NormedAddCommGroup E
inst✝¹ : BorelSpace E
f : β → E
μ : Measure β
fmeas : Measurable f
hf : Memℒp f 1
s : Set E
y₀ : E
h₀ : y₀ ∈ s
inst✝ : SeparableSpace ↑s
hi₀ : Memℒp (fun x => y₀) 1
n : ℕ
⊢ Memℒp (↑(approxOn f fmeas s y₀ h₀ n)) 1

Next tactic:
exact memℒp_approxOn fmeas hf h₀ hi₀ n