mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Topology.MetricSpace.HausdorffDistance

Goal state before:
pp: case inr
α : Type u
inst✝ : PseudoEMetricSpace α
s t : Set α
hs : IsCompact s
ht : IsClosed[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] t
hst : Disjoint s t
hne : s.Nonempty
⊢ ∃ r, 0 < r ∧ ∀ x ∈ s, ∀ y ∈ t, ↑r < edist x y

Tactic:
obtain ⟨x, hx, h⟩ := hs.exists_isMinOn hne continuous_infEDist.continuousOn

Goal state after:
case inr
α : Type u
inst✝ : PseudoEMetricSpace α
s t : Set α
hs : IsCompact s
ht : IsClosed[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] t
hst : Disjoint s t
hne : s.Nonempty
x : α
hx : x ∈ s
h : IsMinOn (fun x ↦ infEDist x ?m.68) s x
⊢ ∃ r, 0 < r ∧ ∀ x ∈ s, ∀ y ∈ t, ↑r < edist x y
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝⁴ : TopologicalSpace α
mα : MeasurableSpace α
inst✝³ : BorelSpace α
mβ : TopologicalSpace β
inst✝² : MeasurableSpace β
inst✝¹ : BorelSpace β
μ : Measure α
inst✝ : IsFiniteMeasureOnCompacts μ
f : α ≃ₜ β
K : Set β
hK : IsCompact K
⊢ (map (⇑f) μ) K < ∞

Tactic:
← f.toMeasurableEquiv_coe,

Goal state after:
α : Type u_1
β : Type u_2
inst✝⁴ : TopologicalSpace α
mα : MeasurableSpace α
inst✝³ : BorelSpace α
mβ : TopologicalSpace β
inst✝² : MeasurableSpace β
inst✝¹ : BorelSpace β
μ : Measure α
inst✝ : IsFiniteMeasureOnCompacts μ
f : α ≃ₜ β
K : Set β
hK : IsCompact K
⊢ (map (⇑f.toMeasurableEquiv) μ) K < ∞
Module: Mathlib.Topology.MetricSpace.Thickening

Goal state before:
pp: α : Type u
inst✝ : PseudoEMetricSpace α
δ : ℝ
hδ : δ ≤ 0
E : Set α
⊢ cthickening δ E = closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E

Tactic:
by
  ext x
  simp [mem_closure_iff_infEDist_zero, cthickening, ENNReal.ofReal_eq_zero.2 hδ]

Goal state after:
Module: Mathlib.Topology.MetricSpace.Thickening

Goal state before:
pp: case pos
α : Type u
inst✝ : PseudoEMetricSpace α
E : Set α
s : Set ℝ
hs : ∀ (ε : ℝ), 0 < ε → (s ∩ Ioc 0 ε).Nonempty
hs₀ : s ⊆ Ioi 0
⊢ closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E = ⋂ δ ∈ s, cthickening δ E

pp: case neg
α : Type u
inst✝ : PseudoEMetricSpace α
E : Set α
s : Set ℝ
hs : ∀ (ε : ℝ), 0 < ε → (s ∩ Ioc 0 ε).Nonempty
hs₀ : ¬s ⊆ Ioi 0
⊢ closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E = ⋂ δ ∈ s, cthickening δ E

Tactic:
· rw [← cthickening_zero]
    apply cthickening_eq_iInter_cthickening' _ hs₀ hs

Goal state after:
case neg
α : Type u
inst✝ : PseudoEMetricSpace α
E : Set α
s : Set ℝ
hs : ∀ (ε : ℝ), 0 < ε → (s ∩ Ioc 0 ε).Nonempty
hs₀ : ¬s ⊆ Ioi 0
⊢ closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] E = ⋂ δ ∈ s, cthickening δ E
Module: Mathlib.Topology.MetricSpace.HausdorffDistance

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
s t : Set α
⊢ hausdorffDist s t = hausdorffDist t s

Tactic:
simp [hausdorffDist, hausdorffEDist_comm]

Goal state after:
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Order

Goal state before:
pp: α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : LinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
inst✝ : Countable ι
f : ι → δ → α
g g' : δ → α
hf : ∀ (i : ι), Measurable (f i)
g'_meas : Measurable g'
hι : IsEmpty ι
hs : MeasurableSet ∅
hg : ∀ b ∈ ∅, IsLUB {a | ∃ i, f i b = a} (g b)
hg' : EqOn g g' univ
⊢ g = g'

Tactic:
eqOn_univ

Goal state after:
α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : LinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
inst✝ : Countable ι
f : ι → δ → α
g g' : δ → α
hf : ∀ (i : ι), Measurable (f i)
g'_meas : Measurable g'
hι : IsEmpty ι
hs : MeasurableSet ∅
hg : ∀ b ∈ ∅, IsLUB {a | ∃ i, f i b = a} (g b)
hg' : g = g'
⊢ g = g'
Module: Mathlib.MeasureTheory.Function.SimpleFunc

Goal state before:
pp: α : Type u_1
inst✝ : MeasurableSpace α
f : α → ℝ≥0∞
hf : Measurable f
a : α
h : ⨆ k, ⨆ (_ : ennrealRatEmbed k ≤ f a), ennrealRatEmbed k < f a
q : ℚ
left✝ : 0 ≤ q
lt_q : ⨆ k, ⨆ (_ : ennrealRatEmbed k ≤ f a), ennrealRatEmbed k < ↑(↑q).toNNReal
q_lt : ↑(↑q).toNNReal < f a
this : ↑(↑q).toNNReal ≤ ⨆ k, ⨆ (_ : ennrealRatEmbed k ≤ f a), ennrealRatEmbed k
⊢ False

Tactic:
exact lt_irrefl _ (lt_of_le_of_lt this lt_q)

Goal state after:
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Order

Goal state before:
pp: α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : LinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
μ : Measure δ
inst✝ : Countable ι
f : ι → δ → α
g : δ → α
hf : ∀ (i : ι), AEMeasurable (f i) μ
hg : ∀ᵐ (b : δ) ∂μ, IsLUB {a | ∃ i, f i b = a} (g b)
a✝ : Nontrivial α
hα : Nonempty α
⊢ AEMeasurable g μ

Tactic:
rcases isEmpty_or_nonempty ι with hι | hι

Goal state after:
case inl
α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : LinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
μ : Measure δ
inst✝ : Countable ι
f : ι → δ → α
g : δ → α
hf : ∀ (i : ι), AEMeasurable (f i) μ
hg : ∀ᵐ (b : δ) ∂μ, IsLUB {a | ∃ i, f i b = a} (g b)
a✝ : Nontrivial α
hα : Nonempty α
hι : IsEmpty ι
⊢ AEMeasurable g μ

case inr
α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : LinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
μ : Measure δ
inst✝ : Countable ι
f : ι → δ → α
g : δ → α
hf : ∀ (i : ι), AEMeasurable (f i) μ
hg : ∀ᵐ (b : δ) ∂μ, IsLUB {a | ∃ i, f i b = a} (g b)
a✝ : Nontrivial α
hα : Nonempty α
hι : Nonempty ι
⊢ AEMeasurable g μ
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Order

Goal state before:
pp: α : Type u_1
inst✝⁴ : TopologicalSpace α
mα : MeasurableSpace α
inst✝³ : BorelSpace α
inst✝² : LinearOrder α
inst✝¹ : OrderTopology α
inst✝ : SecondCountableTopology α
s : Set α
h : ∀ x ∈ s, s ∈ 𝓝[>] x
h' : ∀ x ∈ s, ∃ y, x < y
⊢ MeasurableSet s

Tactic:
choose! M hM using h'
  suffices H : (s \ interior s).Countable by
    have : s = interior s ∪ s \ interior s := by rw [union_sdiff_cancel interior_subset]
    rw [this]
    exact isOpen_interior.measurableSet.union H.measurableSet
  have A : ∀ x ∈ s, ∃ y ∈ Ioi x, Ioo x y ⊆ s := fun x hx =>
    (mem_nhdsGT_iff_exists_Ioo_subset' (hM x hx)).1 (h x hx)
  choose! y hy h'y using A
  have B : Set.PairwiseDisjoint (s \ interior s) fun x => Ioo x (y x) := by
    intro x hx x' hx' hxx'
    rcases lt_or_gt_of_ne hxx' with (h' | h')
    · refine disjoint_left.2 fun z hz h'z => ?_
      have : x' ∈ interior s :=
        mem_interior.2 ⟨Ioo x (y x), h'y _ hx.1, isOpen_Ioo, ⟨h', h'z.1.trans hz.2⟩⟩
      exact False.elim (hx'.2 this)
    · refine disjoint_left.2 fun z hz h'z => ?_
      have : x ∈ interior s :=
        mem_interior.2 ⟨Ioo x' (y x'), h'y _ hx'.1, isOpen_Ioo, ⟨h', hz.1.trans h'z.2⟩⟩
      exact False.elim (hx.2 this)
  exact B.countable_of_Ioo fun x hx => hy x hx.1

Goal state after:
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Order

Goal state before:
pp: α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : ConditionallyCompleteLinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
inst✝ : Countable ι
f : ι → δ → α
hf : ∀ (i : ι), Measurable (f i)
⊢ Measurable fun b ↦ ⨆ i, f i b

Tactic:
rcases isEmpty_or_nonempty ι with hι | hι

Goal state after:
case inl
α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : ConditionallyCompleteLinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
inst✝ : Countable ι
f : ι → δ → α
hf : ∀ (i : ι), Measurable (f i)
hι : IsEmpty ι
⊢ Measurable fun b ↦ ⨆ i, f i b

case inr
α : Type u_1
δ : Type u_4
inst✝⁵ : TopologicalSpace α
mα : MeasurableSpace α
inst✝⁴ : BorelSpace α
mδ : MeasurableSpace δ
inst✝³ : ConditionallyCompleteLinearOrder α
inst✝² : OrderTopology α
inst✝¹ : SecondCountableTopology α
ι : Sort u_5
inst✝ : Countable ι
f : ι → δ → α
hf : ∀ (i : ι), Measurable (f i)
hι : Nonempty ι
⊢ Measurable fun b ↦ ⨆ i, f i b
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: case inr.refine_1
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
h₀ : ∫⁻ (a : α), f a ∂μ ≠ 0
L : ℕ → ℝ≥0∞
left✝ : StrictMono L
hLf : ∀ (n : ℕ), L n ∈ Ioo ⊥ (∫⁻ (a : α), f a ∂μ)
hL_tendsto : Tendsto L atTop (𝓝 (∫⁻ (a : α), f a ∂μ))
g : ℕ → α → ℝ≥0∞
hgm : ∀ (n : ℕ), Measurable (g n)
hgf : ∀ (n : ℕ), g n ≤ f
hLg : ∀ (n : ℕ), L n < ∫⁻ (a : α), g n a ∂μ
⊢ ∫⁻ (a : α), f a ∂μ ≤ ∫⁻ (a : α), (fun x ↦ ⨆ n, g n x) a ∂μ

Tactic:
refine le_of_tendsto' hL_tendsto fun n => (hLg n).le.trans <| lintegral_mono fun x => ?_
    exact le_iSup (fun n => g n x) n

Goal state after:
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
β : Type u_5
f : α → β
inst✝¹ : NormedAddCommGroup β
inst✝ : NormedSpace ℝ β
m : MeasurableSpace α
hf : StronglyMeasurable f
c : ℝ
x : α
hfx : ‖f x‖ ≤ c
h_tendsto : Tendsto (fun n ↦ (hf.approx n) x) atTop (𝓝 (f x))
hfx0 : ¬‖f x‖ = 0
⊢ min 1 (c / ‖f x‖) = 1

Tactic:
rw [min_eq_left_iff, one_le_div (lt_of_le_of_ne (norm_nonneg _) (Ne.symm hfx0))]

Goal state after:
α : Type u_1
β : Type u_5
f : α → β
inst✝¹ : NormedAddCommGroup β
inst✝ : NormedSpace ℝ β
m : MeasurableSpace α
hf : StronglyMeasurable f
c : ℝ
x : α
hfx : ‖f x‖ ≤ c
h_tendsto : Tendsto (fun n ↦ (hf.approx n) x) atTop (𝓝 (f x))
hfx0 : ¬‖f x‖ = 0
⊢ ‖f x‖ ≤ c
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : AEMeasurable f μ
h : ∫⁻ (a : α), f a ∂μ = 0
meas_levels_0 : ∀ ε > 0, μ {x | ε ≤ f x} = 0
⊢ f =ᵐ[μ] 0

Tactic:
obtain ⟨u, -, bu, tu⟩ := exists_seq_strictAnti_tendsto' (α := ℝ≥0∞) zero_lt_one

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : AEMeasurable f μ
h : ∫⁻ (a : α), f a ∂μ = 0
meas_levels_0 : ∀ ε > 0, μ {x | ε ≤ f x} = 0
u : ℕ → ℝ≥0∞
bu : ∀ (n : ℕ), u n ∈ Ioo 0 1
tu : Tendsto u atTop (𝓝 0)
⊢ f =ᵐ[μ] 0
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : ℕ → α → ℝ≥0∞
hf : ∀ (n : ℕ), AEMeasurable (f n) μ
h_mono : ∀ᵐ (x : α) ∂μ, Monotone fun n ↦ f n x
⊢ ∫⁻ (a : α), ⨆ n, f n a ∂μ = ⨆ n, ∫⁻ (a : α), f n a ∂μ

Tactic:
simp_rw [← iSup_apply]

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : ℕ → α → ℝ≥0∞
hf : ∀ (n : ℕ), AEMeasurable (f n) μ
h_mono : ∀ᵐ (x : α) ∂μ, Monotone fun n ↦ f n x
⊢ ∫⁻ (a : α), (⨆ i, f i) a ∂μ = ⨆ n, ∫⁻ (a : α), f n a ∂μ
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: case mpr
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : AEMeasurable f μ
h : ∫⁻ (a : α), f a ∂μ = 0
meas_levels_0 : ∀ ε > 0, μ {x | ε ≤ f x} = 0
u : ℕ → ℝ≥0∞
bu : ∀ (n : ℕ), u n ∈ Ioo 0 1
tu : ∀ ε > 0, ∃ N, ∀ n ≥ N, u n ≤ ε
x : α
h' : ∃ i, x ∈ {x | u i ≤ f x}
⊢ 0 < f x

Tactic:
obtain ⟨n, hn⟩ := h'

Goal state after:
case mpr
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : AEMeasurable f μ
h : ∫⁻ (a : α), f a ∂μ = 0
meas_levels_0 : ∀ ε > 0, μ {x | ε ≤ f x} = 0
u : ℕ → ℝ≥0∞
bu : ∀ (n : ℕ), u n ∈ Ioo 0 1
tu : ∀ ε > 0, ∃ N, ∀ n ≥ N, u n ≤ ε
x : α
n : ℕ
hn : x ∈ {x | u n ≤ f x}
⊢ 0 < f x
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Markov

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : AEMeasurable f μ
ε : ℝ≥0∞
hε : ε ≠ 0
hε' : ε ≠ ∞
⊢ μ {x | ε ≤ f x} * ε ≤ ∫⁻ (a : α), f a ∂μ

Tactic:
mul_comm

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : AEMeasurable f μ
ε : ℝ≥0∞
hε : ε ≠ 0
hε' : ε ≠ ∞
⊢ ε * μ {x | ε ≤ f x} ≤ ∫⁻ (a : α), f a ∂μ
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (b : β), AEMeasurable (f b) μ
h_directed : Directed (fun x1 x2 ↦ x1 ≤ x2) f
⊢ ∫⁻ (a : α), ⨆ b, f b a ∂μ = ⨆ b, ∫⁻ (a : α), f b a ∂μ

Tactic:
simp_rw [← iSup_apply]

Goal state after:
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (b : β), AEMeasurable (f b) μ
h_directed : Directed (fun x1 x2 ↦ x1 ≤ x2) f
⊢ ∫⁻ (a : α), (⨆ i, f i) a ∂μ = ⨆ b, ∫⁻ (a : α), f b a ∂μ
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: case e'_2
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (b : β), AEMeasurable (f b) μ
h_directed : Directed (fun x1 x2 ↦ x1 ≤ x2) f
p : α → (β → ℝ≥0∞) → Prop := fun x f' ↦ Directed LE.le f'
hp : ∀ᵐ (x : α) ∂μ, p x fun i ↦ f i x
h_ae_seq_directed : Directed LE.le (aeSeq hf p)
⊢ ∫⁻ (a : α), (⨆ i, f i) a ∂μ = ∫⁻ (a : α), ⨆ b, aeSeq hf p b a ∂?m.244

Tactic:
simp_rw [← iSup_apply]

Goal state after:
case e'_2
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (b : β), AEMeasurable (f b) μ
h_directed : Directed (fun x1 x2 ↦ x1 ≤ x2) f
p : α → (β → ℝ≥0∞) → Prop := fun x f' ↦ Directed LE.le f'
hp : ∀ᵐ (x : α) ∂μ, p x fun i ↦ f i x
h_ae_seq_directed : Directed LE.le (aeSeq hf p)
⊢ ∫⁻ (a : α), (⨆ i, f i) a ∂μ = ∫⁻ (a : α), (⨆ i, aeSeq hf p i) a ∂?m.244
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
B : Set α
f : α → ℝ≥0∞
A : Set α
hB : MeasurableSet B
⊢ ∫⁻ (x : α) in A ∩ B, f x ∂μ + ∫⁻ (x : α) in A \ B, f x ∂μ = ∫⁻ (x : α) in A, f x ∂μ

Tactic:
by
  rw [← lintegral_add_measure, restrict_inter_add_sdiff _ hB]

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hf : Measurable f
hg : Measurable g
⊢ ∫⁻ (a : α), f a + g a ∂μ = ∫⁻ (a : α), (⨆ n, (eapprox f n) a) + ⨆ n, (eapprox g n) a ∂μ

Tactic:
by
      simp only [iSup_eapprox_apply, hf, hg]

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Sub

Goal state before:
pp: α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : ∫⁻ (a : α), f a ∂μ ≠ ∞
ε : ℝ≥0∞
hε : ε ≠ 0
hf₀ : ¬∫⁻ (a : α), f a ∂μ = 0
g : α → ℝ≥0∞
hgf : g ≤ f
hg_meas : Measurable g
hgsupp : μ (support g) < ∞
hgε : ∫⁻ (a : α), f a ∂μ - ε < ∫⁻ (a : α), g a ∂μ
⊢ Set.EqOn f (fun a ↦ f a - g a) (support g)ᶜ

Tactic:
intro

Goal state after:
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : ∫⁻ (a : α), f a ∂μ ≠ ∞
ε : ℝ≥0∞
hε : ε ≠ 0
hf₀ : ¬∫⁻ (a : α), f a ∂μ = 0
g : α → ℝ≥0∞
hgf : g ≤ f
hg_meas : Measurable g
hgsupp : μ (support g) < ∞
hgε : ∫⁻ (a : α), f a ∂μ - ε < ∫⁻ (a : α), g a ∂μ
x✝ : α
⊢ x✝ ∈ (support g)ᶜ → f x✝ = (fun a ↦ f a - g a) x✝
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: case refine_1
α : Type u_1
β : Type u_2
γ : Type u_3
m : MeasurableSpace α
inst✝³ : TopologicalSpace β
inst✝² : PseudoMetrizableSpace β
inst✝¹ : TopologicalSpace γ
inst✝ : PseudoMetrizableSpace γ
g : β → γ
f : α → β
hg : IsEmbedding g
this : PseudoMetricSpace γ := pseudoMetrizableSpacePseudoMetric γ
this✝³ : MeasurableSpace β := borel β
this✝² : BorelSpace β
this✝¹ : MeasurableSpace γ := borel γ
this✝ : BorelSpace γ
H : StronglyMeasurable fun x ↦ g (f x)
⊢ Measurable f

pp: case refine_2
α : Type u_1
β : Type u_2
γ : Type u_3
m : MeasurableSpace α
inst✝³ : TopologicalSpace β
inst✝² : PseudoMetrizableSpace β
inst✝¹ : TopologicalSpace γ
inst✝ : PseudoMetrizableSpace γ
g : β → γ
f : α → β
hg : IsEmbedding g
this : PseudoMetricSpace γ := pseudoMetrizableSpacePseudoMetric γ
this✝³ : MeasurableSpace β := borel β
this✝² : BorelSpace β
this✝¹ : MeasurableSpace γ := borel γ
this✝ : BorelSpace γ
H : StronglyMeasurable fun x ↦ g (f x)
⊢ IsSeparable (range f)

Tactic:
· let G : β → range g := rangeFactorization g
    have hG : IsClosedEmbedding G :=
      { hg.codRestrict _ _ with
        isClosed_range := by
          rw [rangeFactorization_surjective.range_eq]
          exact isClosed_univ }
    have : Measurable (G ∘ f) := Measurable.subtype_mk H.measurable
    exact hG.measurableEmbedding.measurable_comp_iff.1 this

Goal state after:
case refine_2
α : Type u_1
β : Type u_2
γ : Type u_3
m : MeasurableSpace α
inst✝³ : TopologicalSpace β
inst✝² : PseudoMetrizableSpace β
inst✝¹ : TopologicalSpace γ
inst✝ : PseudoMetrizableSpace γ
g : β → γ
f : α → β
hg : IsEmbedding g
this : PseudoMetricSpace γ := pseudoMetrizableSpacePseudoMetric γ
this✝³ : MeasurableSpace β := borel β
this✝² : BorelSpace β
this✝¹ : MeasurableSpace γ := borel γ
this✝ : BorelSpace γ
H : StronglyMeasurable fun x ↦ g (f x)
⊢ IsSeparable (range f)
Module: Mathlib.MeasureTheory.Measure.Decomposition.Exhaustion

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
⊢ MeasurableSet (μ.sigmaFiniteSetWRT ν)

Tactic:
rw [Measure.sigmaFiniteSetWRT]
  split_ifs with h
  · exact h.choose_spec.1
  · exact MeasurableSet.empty

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Decomposition.Exhaustion

Goal state before:
pp: case neg
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
s t : Set α
h : ¬∃ s, MeasurableSet s ∧ SigmaFinite (μ.restrict s) ∧ ∀ t ⊆ sᶜ, ν t ≠ 0 → μ t = ∞
⊢ SigmaFinite 0

Tactic:
infer_instance

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Decomposition.Exhaustion

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
inst✝ : IsFiniteMeasure ν
n : ℕ
hC_lt : ⨆ s, ⨆ (_ : MeasurableSet s), ⨆ (_ : SigmaFinite (μ.restrict s)), ν s ≤ 1 / ↑n
⊢ SigmaFinite 0

Tactic:
infer_instance

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
hr : r ≠ ∞
h : ¬r = 0
rinv : r * r⁻¹ = 1
⊢ r⁻¹ * r = 1

Tactic:
mul_comm

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
hr : r ≠ ∞
h : ¬r = 0
rinv : r * r⁻¹ = 1
⊢ r * r⁻¹ = 1
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: case inl
α : Type u_1
β : Type u_2
inst✝⁵ : MeasurableSpace α
inst✝⁴ : TopologicalSpace α
inst✝³ : OpensMeasurableSpace α
inst✝² : MeasurableSingletonClass α
inst✝¹ : TopologicalSpace β
inst✝ : PseudoMetrizableSpace β
h : SecondCountableTopologyEither α β
f : α → β
s : Set α
hf : ContinuousOn f s
hs : sᶜ.Countable
h's : MeasurableSet s
this : f = fun x ↦ if hx : x ∈ s then f ↑⟨x, hx⟩ else f ↑⟨x, hx⟩
h✝ : SecondCountableTopology α
⊢ SecondCountableTopologyEither (↑s) β

Tactic:
infer_instance

Goal state after:
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: case inr
α : Type u_1
β : Type u_2
inst✝⁵ : MeasurableSpace α
inst✝⁴ : TopologicalSpace α
inst✝³ : OpensMeasurableSpace α
inst✝² : MeasurableSingletonClass α
inst✝¹ : TopologicalSpace β
inst✝ : PseudoMetrizableSpace β
h : SecondCountableTopologyEither α β
f : α → β
s : Set α
hf : ContinuousOn f s
hs : sᶜ.Countable
h's : MeasurableSet s
this : f = fun x ↦ if hx : x ∈ s then f ↑⟨x, hx⟩ else f ↑⟨x, hx⟩
h✝ : SecondCountableTopology β
⊢ SecondCountableTopologyEither (↑s) β

Tactic:
infer_instance

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.DominatedConvergence

Goal state before:
pp: case refine_2
α : Type u_1
inst✝¹ : MeasurableSpace α
μ : Measure α
ι : Type u_2
l : Filter ι
inst✝ : l.IsCountablyGenerated
F : ι → α → ℝ≥0∞
f bound : α → ℝ≥0∞
hF_meas : ∀ᶠ (n : ι) in l, AEMeasurable (F n) μ
h_bound : ∀ᶠ (n : ι) in l, ∀ᵐ (a : α) ∂μ, F n a ≤ bound a
h_fin : ∫⁻ (a : α), bound a ∂μ ≠ ∞
h_lim : ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ F n a) l (𝓝 (f a))
x : ℕ → ι
xl : Tendsto x atTop l
hxl : ∀ s ∈ l, ∃ a, ∀ (b : ℕ), a ≤ b → x b ∈ s
k : ℕ
h : ∀ (b : ℕ), k ≤ b → x b ∈ {x | (fun n ↦ AEMeasurable (F n) μ) x} ∩ {x | (fun n ↦ ∀ᵐ (a : α) ∂μ, F n a ≤ bound a) x}
⊢ ∀ (n : ℕ), AEMeasurable (F (x (n + k))) μ

Tactic:
intro

Goal state after:
case refine_2
α : Type u_1
inst✝¹ : MeasurableSpace α
μ : Measure α
ι : Type u_2
l : Filter ι
inst✝ : l.IsCountablyGenerated
F : ι → α → ℝ≥0∞
f bound : α → ℝ≥0∞
hF_meas : ∀ᶠ (n : ι) in l, AEMeasurable (F n) μ
h_bound : ∀ᶠ (n : ι) in l, ∀ᵐ (a : α) ∂μ, F n a ≤ bound a
h_fin : ∫⁻ (a : α), bound a ∂μ ≠ ∞
h_lim : ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ F n a) l (𝓝 (f a))
x : ℕ → ι
xl : Tendsto x atTop l
hxl : ∀ s ∈ l, ∃ a, ∀ (b : ℕ), a ≤ b → x b ∈ s
k : ℕ
h : ∀ (b : ℕ), k ≤ b → x b ∈ {x | (fun n ↦ AEMeasurable (F n) μ) x} ∩ {x | (fun n ↦ ∀ᵐ (a : α) ∂μ, F n a ≤ bound a) x}
n✝ : ℕ
⊢ AEMeasurable (F (x (n✝ + k))) μ
Module: Mathlib.MeasureTheory.Measure.Decomposition.Exhaustion

Goal state before:
pp: case refine_1
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
s : Set α
inst✝ : IsFiniteMeasure ν
hs : MeasurableSet s
hs_subset : s ⊆ (μ.sigmaFiniteSetWRT' ν)ᶜ
hνs : ν s ≠ 0
hsσ : SigmaFinite (μ.restrict s)
h_lt : ν (μ.sigmaFiniteSetWRT' ν) < ν (μ.sigmaFiniteSetWRT' ν ∪ s)
this : SigmaFinite (μ.restrict (μ.sigmaFiniteSetWRT' ν))
⊢ SigmaFinite (μ.restrict (μ.sigmaFiniteSetWRT' ν ∪ s))

Tactic:
infer_instance

Goal state after:
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: case const
α : Type u_1
β : Type u_2
inst✝² : MeasurableSpace α
inst✝¹ : AddZeroClass β
inst✝ : TopologicalSpace β
P : (f : α → β) → StronglyMeasurable f → Prop
ind : ∀ (c : β) ⦃s : Set α⦄ (hs : MeasurableSet s), P (s.indicator fun x ↦ c) ⋯
add :
  ∀ ⦃f g : α → β⦄ (hf : StronglyMeasurable f) (hg : StronglyMeasurable g) (hfg : StronglyMeasurable (f + g)),
    Disjoint (support f) (support g) → P f hf → P g hg → P (f + g) hfg
lim :
  ∀ ⦃f : ℕ → α → β⦄ ⦃g : α → β⦄ (hf : ∀ (n : ℕ), StronglyMeasurable (f n)) (hg : StronglyMeasurable g),
    (∀ (n : ℕ), P (f n) ⋯) → (∀ (x : α), Tendsto (fun x_1 ↦ f x_1 x) atTop (𝓝 (g x))) → P g hg
f : α → β
hf : StronglyMeasurable f
s : ℕ → α →ₛ β := hf.approx
n : ℕ
c : β
s✝ : Set α
hs : MeasurableSet s✝
⊢ P ⇑(SimpleFunc.piecewise s✝ hs (SimpleFunc.const α c) (SimpleFunc.const α 0)) ⋯

Tactic:
exact ind c hs

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: case refine_3
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
f : α → ℝ≥0∞
hf : Measurable f
⊢ ∀ ⦃f : ℕ → α → ℝ≥0∞⦄,
    (∀ (n : ℕ), Measurable (f n)) →
      Monotone f →
        (∀ (n : ℕ), ∫⁻ (a : α), f n a ∂μ.trim hm = ∫⁻ (a : α), f n a ∂μ) →
          ∫⁻ (a : α), (fun x ↦ ⨆ n, f n x) a ∂μ.trim hm = ∫⁻ (a : α), (fun x ↦ ⨆ n, f n x) a ∂μ

Tactic:
intro f hf hf_mono hf_prop
    rw [lintegral_iSup hf hf_mono]
    rw [lintegral_iSup (fun n => Measurable.mono (hf n) hm le_rfl) hf_mono]
    congr with n
    exact hf_prop n

Goal state after:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.DominatedConvergence

Goal state before:
pp: case refine_3
α : Type u_1
inst✝¹ : MeasurableSpace α
μ : Measure α
ι : Type u_2
l : Filter ι
inst✝ : l.IsCountablyGenerated
F : ι → α → ℝ≥0∞
f bound : α → ℝ≥0∞
hF_meas : ∀ᶠ (n : ι) in l, AEMeasurable (F n) μ
h_bound : ∀ᶠ (n : ι) in l, ∀ᵐ (a : α) ∂μ, F n a ≤ bound a
h_fin : ∫⁻ (a : α), bound a ∂μ ≠ ∞
h_lim : ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ F n a) l (𝓝 (f a))
x : ℕ → ι
xl : Tendsto x atTop l
hxl : ∀ s ∈ l, ∃ a, ∀ (b : ℕ), a ≤ b → x b ∈ s
k : ℕ
h : ∀ (b : ℕ), k ≤ b → x b ∈ {x | (fun n ↦ AEMeasurable (F n) μ) x} ∩ {x | (fun n ↦ ∀ᵐ (a : α) ∂μ, F n a ≤ bound a) x}
⊢ ∀ (n : ℕ), F (x (n + k)) ≤ᵐ[μ] bound

Tactic:
intro

Goal state after:
case refine_3
α : Type u_1
inst✝¹ : MeasurableSpace α
μ : Measure α
ι : Type u_2
l : Filter ι
inst✝ : l.IsCountablyGenerated
F : ι → α → ℝ≥0∞
f bound : α → ℝ≥0∞
hF_meas : ∀ᶠ (n : ι) in l, AEMeasurable (F n) μ
h_bound : ∀ᶠ (n : ι) in l, ∀ᵐ (a : α) ∂μ, F n a ≤ bound a
h_fin : ∫⁻ (a : α), bound a ∂μ ≠ ∞
h_lim : ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ F n a) l (𝓝 (f a))
x : ℕ → ι
xl : Tendsto x atTop l
hxl : ∀ s ∈ l, ∃ a, ∀ (b : ℕ), a ≤ b → x b ∈ s
k : ℕ
h : ∀ (b : ℕ), k ≤ b → x b ∈ {x | (fun n ↦ AEMeasurable (F n) μ) x} ∩ {x | (fun n ↦ ∀ᵐ (a : α) ∂μ, F n a ≤ bound a) x}
n✝ : ℕ
⊢ F (x (n✝ + k)) ≤ᵐ[μ] bound