mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
f : ι → α → β
p : ℝ≥0∞
hf : UnifIntegrable f p μ
⊢ ∀ ⦃ε : ℝ⦄,
    0 < ε →
      ∃ δ,
        ∃ (_ : 0 < δ),
          ∀ (i : ι) (s : Set α),
            MeasurableSet s → μ s ≤ ENNReal.ofReal δ → eLpNorm (s.indicator (-f i)) p μ ≤ ENNReal.ofReal ε

Tactic:
Set.indicator_neg',

Goal state after:
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
f : ι → α → β
p : ℝ≥0∞
hf : UnifIntegrable f p μ
⊢ ∀ ⦃ε : ℝ⦄,
    0 < ε →
      ∃ δ,
        ∃ (_ : 0 < δ),
          ∀ (i : ι) (s : Set α),
            MeasurableSet s → μ s ≤ ENNReal.ofReal δ → eLpNorm (-s.indicator (f i)) p μ ≤ ENNReal.ofReal ε
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
f : ι → α → β
p : ℝ≥0∞
hf : UnifIntegrable f p μ
⊢ UnifIntegrable (-f) p μ

Tactic:
simp_rw [UnifIntegrable, Pi.neg_apply, Set.indicator_neg', eLpNorm_neg]

Goal state after:
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
f : ι → α → β
p : ℝ≥0∞
hf : UnifIntegrable f p μ
⊢ ∀ ⦃ε : ℝ⦄,
    0 < ε →
      ∃ δ,
        ∃ (_ : 0 < δ),
          ∀ (i : ι) (s : Set α),
            MeasurableSet s → μ s ≤ ENNReal.ofReal δ → eLpNorm (s.indicator (f i)) p μ ≤ ENNReal.ofReal ε
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝ : NormedAddCommGroup β
f : α → β
x : α
n : ℕ
hn : n ≥ ⌈↑‖f x‖₊⌉₊ + 1
⊢ {x | ↑n ≤ ↑‖f x‖₊}.indicator f x = 0

Tactic:
Set.indicator_of_notMem

Goal state after:
α : Type u_1
β : Type u_2
inst✝ : NormedAddCommGroup β
f : α → β
x : α
n : ℕ
hn : n ≥ ⌈↑‖f x‖₊⌉₊ + 1
⊢ 0 = 0

case h
α : Type u_1
β : Type u_2
inst✝ : NormedAddCommGroup β
f : α → β
x : α
n : ℕ
hn : n ≥ ⌈↑‖f x‖₊⌉₊ + 1
⊢ x ∉ {x | ↑n ≤ ↑‖f x‖₊}
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
f : α → β
hf : MemLp f 1 μ
hmeas✝ : StronglyMeasurable f
ε : ℝ
hε : 0 < ε
htendsto : ∀ᵐ (x : α) ∂μ, Tendsto (fun M ↦ {x | ↑M ≤ ↑‖f x‖₊}.indicator f x) atTop (𝓝 0)
hmeas : ∀ (M : ℕ), AEStronglyMeasurable ({x | ↑M ≤ ↑‖f x‖₊}.indicator f) μ
hbound : HasFiniteIntegral (fun x ↦ ‖f x‖) μ
n : ℕ
x : α
⊢ x ∈ {x | (fun a ↦ ‖{x | ↑n ≤ ‖f x‖₊}.indicator f a‖ ≤ ‖f a‖) x}

Tactic:
by_cases hx : (n : ℝ) ≤ ‖f x‖

Goal state after:
case pos
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
f : α → β
hf : MemLp f 1 μ
hmeas✝ : StronglyMeasurable f
ε : ℝ
hε : 0 < ε
htendsto : ∀ᵐ (x : α) ∂μ, Tendsto (fun M ↦ {x | ↑M ≤ ↑‖f x‖₊}.indicator f x) atTop (𝓝 0)
hmeas : ∀ (M : ℕ), AEStronglyMeasurable ({x | ↑M ≤ ↑‖f x‖₊}.indicator f) μ
hbound : HasFiniteIntegral (fun x ↦ ‖f x‖) μ
n : ℕ
x : α
hx : ↑n ≤ ‖f x‖
⊢ x ∈ {x | (fun a ↦ ‖{x | ↑n ≤ ‖f x‖₊}.indicator f a‖ ≤ ‖f a‖) x}

case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
f : α → β
hf : MemLp f 1 μ
hmeas✝ : StronglyMeasurable f
ε : ℝ
hε : 0 < ε
htendsto : ∀ᵐ (x : α) ∂μ, Tendsto (fun M ↦ {x | ↑M ≤ ↑‖f x‖₊}.indicator f x) atTop (𝓝 0)
hmeas : ∀ (M : ℕ), AEStronglyMeasurable ({x | ↑M ≤ ↑‖f x‖₊}.indicator f) μ
hbound : HasFiniteIntegral (fun x ↦ ‖f x‖) μ
n : ℕ
x : α
hx : ¬↑n ≤ ‖f x‖
⊢ x ∈ {x | (fun a ↦ ‖{x | ↑n ≤ ‖f x‖₊}.indicator f a‖ ≤ ‖f a‖) x}
Module: Mathlib.MeasureTheory.VectorMeasure.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
m : MeasurableSpace α
M : Type u_3
inst✝² : AddCommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : MeasurableSpace β
x✝ : β
v✝ : M
s : Set β
x : β
v : M
f : ℕ → Set β
f_meas : ∀ (i : ℕ), MeasurableSet (f i)
f_disj : Pairwise (Disjoint on f)
⊢ HasSum (fun i ↦ if MeasurableSet (f i) ∧ x ∈ f i then v else 0)
    (if MeasurableSet (⋃ i, f i) ∧ x ∈ ⋃ i, f i then v else 0)

Tactic:
by_cases hx : x ∈ ⋃ i, f i; swap
    · simp only [mem_iUnion, not_exists] at hx
      simp [hx, hasSum_zero]
    have : MeasurableSet (⋃ i, f i) := by
      apply MeasurableSet.iUnion f_meas
    simp only [f_meas, true_and, MeasurableSet.iUnion f_meas, hx, and_self, ↓reduceIte]
    obtain ⟨j, hj⟩ : ∃ j, x ∈ f j := by simpa using hx
    nth_rewrite 2 [show v = if x ∈ f j then v else 0 by simp [hj]]
    apply hasSum_single
    intro i hi
    have : Disjoint (f i) (f j) := f_disj hi
    grind

Goal state after:
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
f : α → β
hf : MemLp f p μ
hmeas : StronglyMeasurable f
ε : ℝ
hε : 0 < ε
hp_ne_zero : ¬p = 0
hp_ne_top : ¬p = ∞
M : ℝ
hM' : 0 ≤ M
hM :
  ∫⁻ (x : α), ‖{x | M ≤ ↑‖‖f x‖ ^ p.toReal‖₊}.indicator (fun x ↦ ‖f x‖ ^ p.toReal) x‖ₑ ∂μ ≤
    ENNReal.ofReal (ε ^ p.toReal)
x : α
hiff : M ^ (1 / p.toReal) ≤ ↑‖f x‖₊ ↔ M ≤ ↑‖‖f x‖ ^ p.toReal‖₊
hx : x ∉ {x | M ^ (1 / p.toReal) ≤ ↑‖f x‖₊}
⊢ 0 ^ p.toReal = {x | M ≤ ↑‖‖f x‖ ^ p.toReal‖₊}.indicator (fun a ↦ ‖‖f a‖ ^ p.toReal‖ₑ) x

Tactic:
Set.indicator_of_notMem

Goal state after:
case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
f : α → β
hf : MemLp f p μ
hmeas : StronglyMeasurable f
ε : ℝ
hε : 0 < ε
hp_ne_zero : ¬p = 0
hp_ne_top : ¬p = ∞
M : ℝ
hM' : 0 ≤ M
hM :
  ∫⁻ (x : α), ‖{x | M ≤ ↑‖‖f x‖ ^ p.toReal‖₊}.indicator (fun x ↦ ‖f x‖ ^ p.toReal) x‖ₑ ∂μ ≤
    ENNReal.ofReal (ε ^ p.toReal)
x : α
hiff : M ^ (1 / p.toReal) ≤ ↑‖f x‖₊ ↔ M ≤ ↑‖‖f x‖ ^ p.toReal‖₊
hx : x ∉ {x | M ^ (1 / p.toReal) ≤ ↑‖f x‖₊}
⊢ 0 ^ p.toReal = 0

case neg.h
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
f : α → β
hf : MemLp f p μ
hmeas : StronglyMeasurable f
ε : ℝ
hε : 0 < ε
hp_ne_zero : ¬p = 0
hp_ne_top : ¬p = ∞
M : ℝ
hM' : 0 ≤ M
hM :
  ∫⁻ (x : α), ‖{x | M ≤ ↑‖‖f x‖ ^ p.toReal‖₊}.indicator (fun x ↦ ‖f x‖ ^ p.toReal) x‖ₑ ∂μ ≤
    ENNReal.ofReal (ε ^ p.toReal)
x : α
hiff : M ^ (1 / p.toReal) ≤ ↑‖f x‖₊ ↔ M ≤ ↑‖‖f x‖ ^ p.toReal‖₊
hx : x ∉ {x | M ^ (1 / p.toReal) ≤ ↑‖f x‖₊}
⊢ x ∉ {x | M ≤ ↑‖‖f x‖ ^ p.toReal‖₊}
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
f : α → β
hp_top : p ≠ ∞
ε : ℝ
hε : 0 < ε
M : ℝ
hf : ∀ (x : α), ‖f x‖ < M
hM : 0 < M
s : Set α
hs : MeasurableSet s
hμ : μ s ≤ ENNReal.ofReal ((ε / M) ^ p.toReal)
hp : ¬p = 0
haebdd : ∀ᵐ (x : α) ∂μ.restrict s, ‖f x‖ ≤ M
⊢ μ s ^ p.toReal⁻¹ ≤ ENNReal.ofReal ε / ENNReal.ofReal M

Tactic:
ENNReal.rpow_inv_le_iff (ENNReal.toReal_pos hp hp_top)

Goal state after:
case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
f : α → β
hp_top : p ≠ ∞
ε : ℝ
hε : 0 < ε
M : ℝ
hf : ∀ (x : α), ‖f x‖ < M
hM : 0 < M
s : Set α
hs : MeasurableSet s
hμ : μ s ≤ ENNReal.ofReal ((ε / M) ^ p.toReal)
hp : ¬p = 0
haebdd : ∀ᵐ (x : α) ∂μ.restrict s, ‖f x‖ ≤ M
⊢ μ s ≤ (ENNReal.ofReal ε / ENNReal.ofReal M) ^ p.toReal
Module: Mathlib.MeasureTheory.VectorMeasure.Decomposition.Jordan

Goal state before:
pp: case negPart
α : Type u_1
inst✝ : MeasurableSpace α
j₁ j₂ : JordanDecomposition α
hj : j₁.posPart = j₂.posPart
hj' : j₁.negPart.toSignedMeasure = j₂.negPart.toSignedMeasure
⊢ j₁.negPart.toSignedMeasure = j₂.negPart.toSignedMeasure

Tactic:
exact hj'

Goal state after:
Module: Mathlib.MeasureTheory.VectorMeasure.Basic

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
M : Type u_4
N : Type u_5
inst✝⁶ : AddCommMonoid M
inst✝⁵ : TopologicalSpace M
inst✝⁴ : AddCommMonoid N
inst✝³ : TopologicalSpace N
R : Type u_6
inst✝² : Semiring R
inst✝¹ : DistribMulAction R M
inst✝ : ContinuousConstSMul R M
r : R
v : VectorMeasure α M
w : VectorMeasure α N
h : v ≪ᵥ w
s : Set α
hs : w s = 0
⊢ (r • v) s = 0

Tactic:
rw [_root_.smul_apply, h hs, smul_zero]

Goal state after:
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ∞
f : ℕ → α → β
g : α → β
hf : ∀ (n : ℕ), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hg' : MemLp g p μ
hui : UnifIntegrable f p μ
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n ↦ f n x) atTop (𝓝 (g x))
ε : ℝ≥0∞
hε : ε > 0
h : ε < ∞
hμ : ¬μ = 0
hε' : 0 < ε.toReal / 3
hdivp : 0 ≤ 1 / p.toReal
hpow : 0 < measureUnivNNReal μ ^ (1 / p.toReal)
δ₁ : ℝ
hδ₁ : 0 < δ₁
heLpNorm₁ :
  ∀ (i : ℕ) (s : Set α),
    MeasurableSet s → μ s ≤ ENNReal.ofReal δ₁ → eLpNorm (s.indicator (f i)) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
δ₂ : ℝ
hδ₂ : 0 < δ₂
heLpNorm₂ :
  ∀ (s : Set α), MeasurableSet s → μ s ≤ ENNReal.ofReal δ₂ → eLpNorm (s.indicator g) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
t : Set α
htm : MeasurableSet t
ht₁ : μ t ≤ ENNReal.ofReal (min δ₁ δ₂)
N : ℕ
hN : ∀ (b : ℕ), N ≤ b → ∀ x ∈ tᶜ, dist (g x) (f b x) < ε.toReal / (3 * ↑(measureUnivNNReal μ) ^ (1 / p.toReal))
n : ℕ
hn : n ≥ N
⊢ eLpNorm (f n - g) p μ ≤ ε

Tactic:
rw [← t.indicator_self_add_compl (f n - g)]

Goal state after:
case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ∞
f : ℕ → α → β
g : α → β
hf : ∀ (n : ℕ), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hg' : MemLp g p μ
hui : UnifIntegrable f p μ
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n ↦ f n x) atTop (𝓝 (g x))
ε : ℝ≥0∞
hε : ε > 0
h : ε < ∞
hμ : ¬μ = 0
hε' : 0 < ε.toReal / 3
hdivp : 0 ≤ 1 / p.toReal
hpow : 0 < measureUnivNNReal μ ^ (1 / p.toReal)
δ₁ : ℝ
hδ₁ : 0 < δ₁
heLpNorm₁ :
  ∀ (i : ℕ) (s : Set α),
    MeasurableSet s → μ s ≤ ENNReal.ofReal δ₁ → eLpNorm (s.indicator (f i)) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
δ₂ : ℝ
hδ₂ : 0 < δ₂
heLpNorm₂ :
  ∀ (s : Set α), MeasurableSet s → μ s ≤ ENNReal.ofReal δ₂ → eLpNorm (s.indicator g) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
t : Set α
htm : MeasurableSet t
ht₁ : μ t ≤ ENNReal.ofReal (min δ₁ δ₂)
N : ℕ
hN : ∀ (b : ℕ), N ≤ b → ∀ x ∈ tᶜ, dist (g x) (f b x) < ε.toReal / (3 * ↑(measureUnivNNReal μ) ^ (1 / p.toReal))
n : ℕ
hn : n ≥ N
⊢ eLpNorm (t.indicator (f n - g) + tᶜ.indicator (f n - g)) p μ ≤ ε
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ∞
f : ℕ → α → β
g : α → β
hf : ∀ (n : ℕ), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hg' : MemLp g p μ
hui : UnifIntegrable f p μ
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n ↦ f n x) atTop (𝓝 (g x))
ε : ℝ≥0∞
hε : ε > 0
h : ε < ∞
hμ : ¬μ = 0
hε' : 0 < ε.toReal / 3
hdivp : 0 ≤ 1 / p.toReal
hpow : 0 < measureUnivNNReal μ ^ (1 / p.toReal)
δ₁ : ℝ
hδ₁ : 0 < δ₁
heLpNorm₁ :
  ∀ (i : ℕ) (s : Set α),
    MeasurableSet s → μ s ≤ ENNReal.ofReal δ₁ → eLpNorm (s.indicator (f i)) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
δ₂ : ℝ
hδ₂ : 0 < δ₂
heLpNorm₂ :
  ∀ (s : Set α), MeasurableSet s → μ s ≤ ENNReal.ofReal δ₂ → eLpNorm (s.indicator g) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
t : Set α
htm : MeasurableSet t
ht₁ : μ t ≤ ENNReal.ofReal (min δ₁ δ₂)
N : ℕ
hN : ∀ (b : ℕ), N ≤ b → ∀ x ∈ tᶜ, dist (g x) (f b x) < ε.toReal / (3 * ↑(measureUnivNNReal μ) ^ (1 / p.toReal))
n : ℕ
hn : n ≥ N
⊢ eLpNorm (t.indicator (f n) + t.indicator (-g)) p μ + eLpNorm (tᶜ.indicator (f n + -g)) p μ ≤ ε

Tactic:
Set.indicator_neg',

Goal state after:
case neg
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝¹ : NormedAddCommGroup β
p : ℝ≥0∞
inst✝ : IsFiniteMeasure μ
hp : 1 ≤ p
hp' : p ≠ ∞
f : ℕ → α → β
g : α → β
hf : ∀ (n : ℕ), StronglyMeasurable (f n)
hg : StronglyMeasurable g
hg' : MemLp g p μ
hui : UnifIntegrable f p μ
hfg : ∀ᵐ (x : α) ∂μ, Tendsto (fun n ↦ f n x) atTop (𝓝 (g x))
ε : ℝ≥0∞
hε : ε > 0
h : ε < ∞
hμ : ¬μ = 0
hε' : 0 < ε.toReal / 3
hdivp : 0 ≤ 1 / p.toReal
hpow : 0 < measureUnivNNReal μ ^ (1 / p.toReal)
δ₁ : ℝ
hδ₁ : 0 < δ₁
heLpNorm₁ :
  ∀ (i : ℕ) (s : Set α),
    MeasurableSet s → μ s ≤ ENNReal.ofReal δ₁ → eLpNorm (s.indicator (f i)) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
δ₂ : ℝ
hδ₂ : 0 < δ₂
heLpNorm₂ :
  ∀ (s : Set α), MeasurableSet s → μ s ≤ ENNReal.ofReal δ₂ → eLpNorm (s.indicator g) p μ ≤ ENNReal.ofReal (ε.toReal / 3)
t : Set α
htm : MeasurableSet t
ht₁ : μ t ≤ ENNReal.ofReal (min δ₁ δ₂)
N : ℕ
hN : ∀ (b : ℕ), N ≤ b → ∀ x ∈ tᶜ, dist (g x) (f b x) < ε.toReal / (3 * ↑(measureUnivNNReal μ) ^ (1 / p.toReal))
n : ℕ
hn : n ≥ N
⊢ eLpNorm (t.indicator (f n) + -t.indicator g) p μ + eLpNorm (tᶜ.indicator (f n + -g)) p μ ≤ ε
Module: Mathlib.MeasureTheory.VectorMeasure.Decomposition.Hahn

Goal state before:
pp: case a
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
f : ℕ → ℝ
left✝ : Antitone f
hf₂ : Tendsto f atTop (nhds (sInf s.measureOfNegatives))
B : ℕ → Set α
hB : ∀ (n : ℕ), B n ∈ {B | MeasurableSet B ∧ s ≤[B] 0} ∧ s (B n) = f n
hB₁ : ∀ (n : ℕ), MeasurableSet (B n)
hB₂ : ∀ (n : ℕ), s ≤[B n] 0
A : Set α := ⋃ n, B n
hA : A = ⋃ n, B n
hA₁ : MeasurableSet A
hA₂ : s ≤[A] 0
n : ℕ
⊢ (fun x ↦ s ((⋃ i, B i) \ B n) + s (B n)) n ≤ s (B n)

Tactic:
refine add_le_of_nonpos_left ?_
        have : s ≤[A] 0 :=
          restrict_le_restrict_iUnion _ _ hB₁ fun m =>
            let ⟨_, h⟩ := (hB m).1
            h
        refine
          nonpos_of_restrict_le_zero _ (restrict_le_zero_subset _ ?_ Set.sdiff_subset this)
        exact MeasurableSet.iUnion hB₁

Goal state after:
Module: Mathlib.MeasureTheory.VectorMeasure.Basic

Goal state before:
pp: case refine_2
α : Type u_1
β : Type u_2
m : MeasurableSpace α
s : SignedMeasure α
i : Set α
hi₁ : MeasurableSet i
hi₂ : 0 ≤[i] s
⊢ ∀ ⦃f : ℕ → Set α⦄ (h : ∀ (i : ℕ), MeasurableSet (f i)),
    Pairwise (Disjoint on f) →
      s.toMeasureOfZeroLE' i hi₂ (⋃ i, f i) ⋯ = ∑' (i_1 : ℕ), s.toMeasureOfZeroLE' i hi₂ (f i_1) ⋯

Tactic:
· intro f hf₁ hf₂
    have h₁ : ∀ n, MeasurableSet (i ∩ f n) := fun n => hi₁.inter (hf₁ n)
    have h₂ : Pairwise (Disjoint on fun n : ℕ => i ∩ f n) := by
      intro n m hnm
      exact ((hf₂ hnm).inf_left' i).inf_right' i
    simp only [toMeasureOfZeroLE', s.restrict_apply hi₁ (MeasurableSet.iUnion hf₁), Set.inter_comm,
      Set.inter_iUnion, s.of_disjoint_iUnion h₁ h₂]
    have h : ∀ n, 0 ≤ s (i ∩ f n) := fun n =>
      s.nonneg_of_zero_le_restrict (s.zero_le_restrict_subset hi₁ Set.inter_subset_left hi₂)
    rw [NNReal.coe_tsum_of_nonneg h, ENNReal.coe_tsum]
    · refine tsum_congr fun n => ?_
      simp_rw [s.restrict_apply hi₁ (hf₁ n), Set.inter_comm]
    · exact (NNReal.summable_mk h).2 (s.m_iUnion h₁ h₂).summable

Goal state after:
Module: Mathlib.MeasureTheory.VectorMeasure.Decomposition.Hahn

Goal state before:
pp: case right.hA
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ MeasurableSet (j ∩ iᶜ)

pp: case right.hB
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ MeasurableSet (i ∩ jᶜ)

Tactic:
· exact hj.inter hi.compl

Goal state after:
case right.hB
α : Type u_1
inst✝ : MeasurableSpace α
s : SignedMeasure α
i j : Set α
hi : MeasurableSet i
hj : MeasurableSet j
hi' : (∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ i → 0 j ≤ s j) ∧ ∀ ⦃j : Set α⦄, MeasurableSet j → j ⊆ iᶜ → s j ≤ 0 j
hj' :
  (∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ j → 0 j_1 ≤ s j_1) ∧
    ∀ ⦃j_1 : Set α⦄, MeasurableSet j_1 → j_1 ⊆ jᶜ → s j_1 ≤ 0 j_1
⊢ MeasurableSet (i ∩ jᶜ)
Module: Mathlib.MeasureTheory.Measure.HasOuterApproxClosed

Goal state before:
pp: X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : HasOuterApproxClosed X
F : Set X
hF : IsClosed[inst✝¹] F
n : ℕ
⊢ (F.indicator fun x ↦ 1) ≤ ⇑(hF.apprSeq n)

Tactic:
intro x
  by_cases hxF : x ∈ F
  · simp only [hxF, indicator_of_mem, apprSeq_apply_eq_one hF n, le_refl]
  · simp only [hxF, not_false_eq_true, indicator_of_notMem, zero_le]

Goal state after:
Module: Mathlib.MeasureTheory.Function.ConditionalExpectation.Real

Goal state before:
pp: case pos
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
R : ℝ≥0
f : α → ℝ
hbdd : ∀ᵐ (x : α) ∂μ, |f x| ≤ ↑R
hnm : m ≤ m0
hfint : Integrable f μ
h : μ {x | (fun x ↦ |μ[f | m] x| ≤ ↑R) x}ᶜ ≠ 0
⊢ False

Tactic:
simp only [← pos_iff_ne_zero, Set.compl_def, Set.mem_ofPred_eq, not_le] at h

Goal state after:
case pos
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
R : ℝ≥0
f : α → ℝ
hbdd : ∀ᵐ (x : α) ∂μ, |f x| ≤ ↑R
hnm : m ≤ m0
hfint : Integrable f μ
h : 0 < μ {x | ↑R < |μ[f | m] x|}
⊢ False
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: case neg
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
hp : 1 ≤ p
hp' : p ≠ ∞
f : ι → α → β
hf : ∀ (i : ι), AEStronglyMeasurable (f i) μ
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
g : ι → α → β := fun i ↦ Exists.choose ⋯
ε : ℝ
hε : 0 < ε
C : ℝ≥0
hC : ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
i : ι
x : α
hx : f i x = Exists.choose ⋯ x
hfx : x ∉ {x | C ≤ ‖f i x‖₊}
⊢ {x | C ≤ ‖g i x‖₊}.indicator (g i) x = 0

Tactic:
Set.indicator_of_notMem

Goal state after:
case neg
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
hp : 1 ≤ p
hp' : p ≠ ∞
f : ι → α → β
hf : ∀ (i : ι), AEStronglyMeasurable (f i) μ
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
g : ι → α → β := fun i ↦ Exists.choose ⋯
ε : ℝ
hε : 0 < ε
C : ℝ≥0
hC : ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
i : ι
x : α
hx : f i x = Exists.choose ⋯ x
hfx : x ∉ {x | C ≤ ‖f i x‖₊}
⊢ 0 = 0

case neg.h
α : Type u_1
β : Type u_2
ι : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
p : ℝ≥0∞
hp : 1 ≤ p
hp' : p ≠ ∞
f : ι → α → β
hf : ∀ (i : ι), AEStronglyMeasurable (f i) μ
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
g : ι → α → β := fun i ↦ Exists.choose ⋯
ε : ℝ
hε : 0 < ε
C : ℝ≥0
hC : ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
i : ι
x : α
hx : f i x = Exists.choose ⋯ x
hfx : x ∉ {x | C ≤ ‖f i x‖₊}
⊢ x ∉ {x | C ≤ ‖g i x‖₊}
Module: Mathlib.MeasureTheory.Measure.ProbabilityMeasure

Goal state before:
pp: case mpr
Ω : Type u_1
inst✝² : Nonempty Ω
m0 : MeasurableSpace Ω
μ : FiniteMeasure Ω
inst✝¹ : TopologicalSpace Ω
inst✝ : OpensMeasurableSpace Ω
γ : Type u_2
F : Filter γ
μs : γ → FiniteMeasure Ω
nonzero : μ ≠ 0
⊢ Tendsto μs F (𝓝 μ) → Tendsto (fun i ↦ (μs i).normalize) F (𝓝 μ.normalize) ∧ Tendsto (fun i ↦ (μs i).mass) F (𝓝 μ.mass)

Tactic:
· intro μs_lim
    exact ⟨tendsto_normalize_of_tendsto μs_lim nonzero, μs_lim.mass⟩

Goal state after:
Module: Mathlib.MeasureTheory.Measure.FiniteMeasure

Goal state before:
pp: Ω : Type u_1
inst✝² : MeasurableSpace Ω
inst✝¹ : TopologicalSpace Ω
inst✝ : OpensMeasurableSpace Ω
γ : Type u_2
F : Filter γ
μs : γ → FiniteMeasure Ω
μ : FiniteMeasure Ω
h : ∀ (f : Ω →ᵇ ℝ), Tendsto (fun i ↦ ∫ (x : Ω), f x ∂↑(μs i)) F (𝓝 (∫ (x : Ω), f x ∂↑μ))
f : Ω →ᵇ ℝ≥0
lip : LipschitzWith 1 NNReal.toReal
f₀ : Ω →ᵇ ℝ := comp NNReal.toReal lip f
_def_f₀ : f₀ = comp NNReal.toReal lip f
f₀_eq : ⇑f₀ = NNReal.toReal ∘ ⇑f
x✝ : Ω
⊢ 0 x✝ ≤ f₀ x✝

Tactic:
by
    simp only [f₀_eq, Pi.zero_apply, Function.comp_apply, NNReal.zero_le_coe]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.FiniteMeasure

Goal state before:
pp: Ω : Type u_1
inst✝² : MeasurableSpace Ω
inst✝¹ : TopologicalSpace Ω
inst✝ : OpensMeasurableSpace Ω
γ : Type u_2
F : Filter γ
μs : γ → FiniteMeasure Ω
μ : FiniteMeasure Ω
h : ∀ (f : Ω →ᵇ ℝ≥0), Tendsto (fun i ↦ ∫⁻ (x : Ω), ↑(f x) ∂↑(μs i)) F (𝓝 (∫⁻ (x : Ω), ↑(f x) ∂↑μ))
f : Ω →ᵇ ℝ
f_pos : Ω →ᵇ ℝ≥0 := f.nnrealPart
_def_f_pos : f_pos = f.nnrealPart
⊢ Tendsto (fun i ↦ ∫ (x : Ω), ↑(f_pos x) ∂↑(μs i) - ∫ (x : Ω), ↑((-f).nnrealPart x) ∂↑(μs i)) F
    (𝓝 (∫ (x : Ω), ↑(f_pos x) ∂↑μ - ∫ (x : Ω), ↑((-f).nnrealPart x) ∂↑μ))

Tactic:
set f_neg := (-f).nnrealPart with _def_f_neg

Goal state after:
Ω : Type u_1
inst✝² : MeasurableSpace Ω
inst✝¹ : TopologicalSpace Ω
inst✝ : OpensMeasurableSpace Ω
γ : Type u_2
F : Filter γ
μs : γ → FiniteMeasure Ω
μ : FiniteMeasure Ω
h : ∀ (f : Ω →ᵇ ℝ≥0), Tendsto (fun i ↦ ∫⁻ (x : Ω), ↑(f x) ∂↑(μs i)) F (𝓝 (∫⁻ (x : Ω), ↑(f x) ∂↑μ))
f : Ω →ᵇ ℝ
f_pos : Ω →ᵇ ℝ≥0 := f.nnrealPart
_def_f_pos : f_pos = f.nnrealPart
f_neg : Ω →ᵇ ℝ≥0 := (-f).nnrealPart
_def_f_neg : f_neg = (-f).nnrealPart
⊢ Tendsto (fun i ↦ ∫ (x : Ω), ↑(f_pos x) ∂↑(μs i) - ∫ (x : Ω), ↑(f_neg x) ∂↑(μs i)) F
    (𝓝 (∫ (x : Ω), ↑(f_pos x) ∂↑μ - ∫ (x : Ω), ↑(f_neg x) ∂↑μ))
Module: Mathlib.MeasureTheory.Function.UniformIntegrable

Goal state before:
pp: case neg
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), AEStronglyMeasurable (f i) μ
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
g : ι → α → β := fun i ↦ Exists.choose ⋯
hgmeas : ∀ (i : ι), StronglyMeasurable (g i)
hgeq : ∀ (i : ι), g i =ᵐ[μ] f i
ε : ℝ
hε : 0 < ε
C : ℝ≥0
hC : ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
i : ι
x : α
hx : f i x = Exists.choose ⋯ x
hfx : x ∉ {x | C ≤ ‖f i x‖₊}
⊢ {x | C ≤ ‖g i x‖₊}.indicator (g i) x = 0

Tactic:
Set.indicator_of_notMem

Goal state after:
case neg
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), AEStronglyMeasurable (f i) μ
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
g : ι → α → β := fun i ↦ Exists.choose ⋯
hgmeas : ∀ (i : ι), StronglyMeasurable (g i)
hgeq : ∀ (i : ι), g i =ᵐ[μ] f i
ε : ℝ
hε : 0 < ε
C : ℝ≥0
hC : ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
i : ι
x : α
hx : f i x = Exists.choose ⋯ x
hfx : x ∉ {x | C ≤ ‖f i x‖₊}
⊢ 0 = 0

case neg.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), AEStronglyMeasurable (f i) μ
h : ∀ (ε : ℝ), 0 < ε → ∃ C, ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
g : ι → α → β := fun i ↦ Exists.choose ⋯
hgmeas : ∀ (i : ι), StronglyMeasurable (g i)
hgeq : ∀ (i : ι), g i =ᵐ[μ] f i
ε : ℝ
hε : 0 < ε
C : ℝ≥0
hC : ∀ (i : ι), eLpNorm ({x | C ≤ ‖f i x‖₊}.indicator (f i)) p μ ≤ ENNReal.ofReal ε
i : ι
x : α
hx : f i x = Exists.choose ⋯ x
hfx : x ∉ {x | C ≤ ‖f i x‖₊}
⊢ x ∉ {x | C ≤ ‖g i x‖₊}