Theorem: MeasureTheory.uniformIntegrable_of'
File: Mathlib/MeasureTheory/Function/UniformIntegrable.lean

tactic: refine' ⟨fun i => (hf i).aestronglyMeasurable,
  unifIntegrable_of μ hp hp' (fun i => (hf i).aestronglyMeasurable) h, _⟩
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
⊢ UniformIntegrable f p μ

tactic: obtain ⟨C, hC⟩ := h 1 one_pos
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
⊢ ∃ C, ∀ (i : ι), snorm (f i) p μ ≤ ↑C

tactic: refine' ⟨((C : ℝ≥0∞) * μ Set.univ ^ p.toReal⁻¹ + 1).toNNReal, fun i => _⟩
state_before: case intro
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
⊢ ∃ C, ∀ (i : ι), snorm (f i) p μ ≤ ↑C

tactic: refine' le_trans (snorm_mono fun x => _) (snorm_add_le
  (StronglyMeasurable.aestronglyMeasurable
    ((hf i).indicator ((hf i).nnnorm.measurableSet_lt stronglyMeasurable_const)))
  (StronglyMeasurable.aestronglyMeasurable
    ((hf i).indicator (stronglyMeasurable_const.measurableSet_le (hf i).nnnorm))) hp)
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
⊢ snorm (f i) p μ ≤
    snorm (Set.indicator {x | ‖f i x‖₊ < C} (f i)) p μ + snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ

tactic: rw [Pi.add_apply, Set.indicator_apply]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
x : α
⊢ ‖f i x‖ ≤ ‖(Set.indicator {x | ‖f i x‖₊ < C} (f i) + Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) x‖

tactic: split_ifs with hx
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
x : α
⊢ ‖f i x‖ ≤ ‖(if x ∈ {x | ‖f i x‖₊ < C} then f i x else 0) + Set.indicator {x | C ≤ ‖f i x‖₊} (f i) x‖

tactic: rw [Set.indicator_of_not_mem, add_zero]
state_before: case inl
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
x : α
hx : x ∈ {x | ‖f i x‖₊ < C}
⊢ ‖f i x‖ ≤ ‖f i x + Set.indicator {x | C ≤ ‖f i x‖₊} (f i) x‖

tactic: simpa using hx
state_before: case inl.h
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
x : α
hx : x ∈ {x | ‖f i x‖₊ < C}
⊢ ¬x ∈ {x | C ≤ ‖f i x‖₊}

tactic: rw [Set.indicator_of_mem, zero_add]
state_before: case inr
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
x : α
hx : ¬x ∈ {x | ‖f i x‖₊ < C}
⊢ ‖f i x‖ ≤ ‖0 + Set.indicator {x | C ≤ ‖f i x‖₊} (f i) x‖

tactic: simpa using hx
state_before: case inr.h
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
x : α
hx : ¬x ∈ {x | ‖f i x‖₊ < C}
⊢ x ∈ {x | C ≤ ‖f i x‖₊}

tactic: have : ∀ᵐ x ∂μ, ‖{ x : α | ‖f i x‖₊ < C }.indicator (f i) x‖₊ ≤ C := by
  refine' eventually_of_forall _
  simp_rw [nnnorm_indicator_eq_indicator_nnnorm]
  exact Set.indicator_le fun x (hx : _ < _) => hx.le
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
⊢ snorm (Set.indicator {x | ‖f i x‖₊ < C} (f i)) p μ + snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤
    ↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹ + 1

tactic: refine' add_le_add (le_trans (snorm_le_of_ae_bound this) _) (ENNReal.ofReal_one ▸ hC i)
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
this : ∀ᵐ (x : α) ∂μ, ‖Set.indicator {x | ‖f i x‖₊ < C} (f i) x‖₊ ≤ C
⊢ snorm (Set.indicator {x | ‖f i x‖₊ < C} (f i)) p μ + snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤
    ↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹ + 1

tactic: simp_rw [NNReal.val_eq_coe, ENNReal.ofReal_coe_nnreal, mul_comm]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
this : ∀ᵐ (x : α) ∂μ, ‖Set.indicator {x | ‖f i x‖₊ < C} (f i) x‖₊ ≤ C
⊢ ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹ * ENNReal.ofReal ((fun a => ↑a) C) ≤ ↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹

tactic: exact le_rfl
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
this : ∀ᵐ (x : α) ∂μ, ‖Set.indicator {x | ‖f i x‖₊ < C} (f i) x‖₊ ≤ C
⊢ ↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹ ≤ ↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹

tactic: refine' eventually_of_forall _
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
⊢ ∀ᵐ (x : α) ∂μ, ‖Set.indicator {x | ‖f i x‖₊ < C} (f i) x‖₊ ≤ C

tactic: simp_rw [nnnorm_indicator_eq_indicator_nnnorm]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
⊢ ∀ (x : α), ‖Set.indicator {x | ‖f i x‖₊ < C} (f i) x‖₊ ≤ C

tactic: exact Set.indicator_le fun x (hx : _ < _) => hx.le
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
⊢ ∀ (x : α), Set.indicator {x | ‖f i x‖₊ < C} (fun a => ‖f i a‖₊) x ≤ C

tactic: rw [ENNReal.coe_toNNReal]
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
⊢ ↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹ + 1 = ↑(ENNReal.toNNReal (↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹ + 1))

tactic: exact ENNReal.add_ne_top.2
  ⟨ENNReal.mul_ne_top ENNReal.coe_ne_top (ENNReal.rpow_ne_top_of_nonneg
    (inv_nonneg.2 ENNReal.toReal_nonneg) (measure_lt_top _ _).ne),
  ENNReal.one_ne_top⟩
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
f : ι → α → β
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ⊤
hf : ∀ (i : ι), StronglyMeasurable (f i)
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal ε
C : ℝ≥0
hC : ∀ (i : ι), snorm (Set.indicator {x | C ≤ ‖f i x‖₊} (f i)) p μ ≤ ENNReal.ofReal 1
i : ι
⊢ ↑C * ↑↑μ Set.univ ^ (ENNReal.toReal p)⁻¹ + 1 ≠ ⊤