mathlib-initiative/mathlib-tactics huggingface dataset:
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), Measurable (f n)
h_mono : Monotone f
c : ℝ≥0 → ℝ≥0∞ := ofNNReal
F : α → ℝ≥0∞ := fun a ↦ ⨆ n, f n a
s : α →ₛ ℝ≥0
hsf : ∀ (x : α), ↑(s x) ≤ ⨆ n, f n x
r : ℝ≥0
right✝ ha✝ : ↑r < 1
ha : r < 1
rs : α →ₛ ℝ≥0 := SimpleFunc.map (fun a ↦ r * a) s
eq_rs : SimpleFunc.map c rs = const α ↑r * SimpleFunc.map c s
eq : ∀ (p : ℝ≥0∞), ⇑(SimpleFunc.map c rs) ⁻¹' {p} = ⋃ n, ⇑(SimpleFunc.map c rs) ⁻¹' {p} ∩ {a | p ≤ f n a}
⊢ ∀ (r : ℝ≥0∞), Monotone fun n ↦ ⇑(SimpleFunc.map c rs) ⁻¹' {r} ∩ {a | r ≤ f n a}

Tactic:
intro r i j h

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f : ℕ → α → ℝ≥0∞
hf : ∀ (n : ℕ), Measurable (f n)
h_mono : Monotone f
c : ℝ≥0 → ℝ≥0∞ := ofNNReal
F : α → ℝ≥0∞ := fun a ↦ ⨆ n, f n a
s : α →ₛ ℝ≥0
hsf : ∀ (x : α), ↑(s x) ≤ ⨆ n, f n x
r✝ : ℝ≥0
right✝ ha✝ : ↑r✝ < 1
ha : r✝ < 1
rs : α →ₛ ℝ≥0 := SimpleFunc.map (fun a ↦ r✝ * a) s
eq_rs : SimpleFunc.map c rs = const α ↑r✝ * SimpleFunc.map c s
eq : ∀ (p : ℝ≥0∞), ⇑(SimpleFunc.map c rs) ⁻¹' {p} = ⋃ n, ⇑(SimpleFunc.map c rs) ⁻¹' {p} ∩ {a | p ≤ f n a}
r : ℝ≥0∞
i j : ℕ
h : i ≤ j
⊢ (fun n ↦ ⇑(SimpleFunc.map c rs) ⁻¹' {r} ∩ {a | r ≤ f n a}) i ⊆
    (fun n ↦ ⇑(SimpleFunc.map c rs) ⁻¹' {r} ∩ {a | r ≤ f n a}) j
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: case neg.inr
α : Type u_1
β : Type u_5
f : α → β
inst✝¹ : SeminormedAddCommGroup β
inst✝ : NormedSpace ℝ β
m : MeasurableSpace α
c : ℝ
hf : StronglyMeasurable f
hc : 0 ≤ c
n : ℕ
x : α
h0 : ¬‖(hf.approx n) x‖ = 0
h : c ≤ ‖(hf.approx n) x‖
⊢ ‖c / ‖(hf.approx n) x‖‖ * ‖(hf.approx n) x‖ ≤ c

Tactic:
rw [norm_div, norm_norm, mul_comm, mul_div, div_eq_mul_inv, mul_comm, ← mul_assoc,
        inv_mul_cancel₀ h0, one_mul, Real.norm_of_nonneg hc]

Goal state after:
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
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
b₁ b₂ z : β
hz₁ : f b₁ ≤ f z
hz₂ : f b₂ ≤ f z
⊢ ∃ z, aeSeq hf p b₁ ≤ aeSeq hf p z ∧ aeSeq hf p b₂ ≤ aeSeq hf p z

Tactic:
refine ⟨z, ?_, ?_⟩

Goal state after:
case refine_1
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
b₁ b₂ z : β
hz₁ : f b₁ ≤ f z
hz₂ : f b₂ ≤ f z
⊢ aeSeq hf p b₁ ≤ aeSeq hf p z

case refine_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
b₁ b₂ z : β
hz₁ : f b₁ ≤ f z
hz₂ : f b₂ ≤ f z
⊢ aeSeq hf p b₂ ≤ aeSeq hf p z
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

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

Tactic:
funext a

Goal state after:
case e_f
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hf : Measurable f
hg : Measurable g
a : α
⊢ (⨆ n, (eapprox f n) a) + ⨆ n, (eapprox g n) a = ⨆ n, (⇑(eapprox f n) + ⇑(eapprox g n)) a
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
M : Type u_5
inst✝² : CommMonoid M
inst✝¹ : TopologicalSpace M
inst✝ : ContinuousMul M
m : MeasurableSpace α
n : MeasurableSpace β
ι : Type u_6
f : ι → α → β → M
g : α → β
s : Finset ι
hf : ∀ i ∈ s, StronglyMeasurable ↿(f i)
hg : Measurable g
⊢ StronglyMeasurable fun a ↦ (∏ i ∈ s, f i a) (g a)

Tactic:
simp only [Finset.prod_apply]; fun_prop

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

Goal state before:
pp: α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
F : ℕ → α → ℝ≥0∞
f bound : α → ℝ≥0∞
hF_meas : ∀ (n : ℕ), AEMeasurable (F n) μ
h_bound : ∀ (n : ℕ), F n ≤ᵐ[μ] bound
h_fin : ∫⁻ (a : α), bound a ∂μ ≠ ∞
h_lim : ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ F n a) atTop (𝓝 (f a))
this✝¹ : ∀ (n : ℕ), ∫⁻ (a : α), F n a ∂μ = ∫⁻ (a : α), AEMeasurable.mk (F n) ⋯ a ∂μ
this✝ : ∀ (n : ℕ), ∀ᵐ (a : α) ∂μ, AEMeasurable.mk (F n) ⋯ a = F n a
this : ∀ᵐ (a : α) ∂μ, ∀ (n : ℕ), AEMeasurable.mk (F n) ⋯ a = F n a
⊢ ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ AEMeasurable.mk (F n) ⋯ a) atTop (𝓝 (f a))

Tactic:
filter_upwards [this, h_lim] with a H H'

Goal state after:
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
F : ℕ → α → ℝ≥0∞
f bound : α → ℝ≥0∞
hF_meas : ∀ (n : ℕ), AEMeasurable (F n) μ
h_bound : ∀ (n : ℕ), F n ≤ᵐ[μ] bound
h_fin : ∫⁻ (a : α), bound a ∂μ ≠ ∞
h_lim : ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ F n a) atTop (𝓝 (f a))
this✝¹ : ∀ (n : ℕ), ∫⁻ (a : α), F n a ∂μ = ∫⁻ (a : α), AEMeasurable.mk (F n) ⋯ a ∂μ
this✝ : ∀ (n : ℕ), ∀ᵐ (a : α) ∂μ, AEMeasurable.mk (F n) ⋯ a = F n a
this : ∀ᵐ (a : α) ∂μ, ∀ (n : ℕ), AEMeasurable.mk (F n) ⋯ a = F n a
a : α
H : ∀ (n : ℕ), AEMeasurable.mk (F n) ⋯ a = F n a
H' : Tendsto (fun n ↦ F n a) atTop (𝓝 (f a))
⊢ Tendsto (fun n ↦ AEMeasurable.mk (F n) ⋯ a) atTop (𝓝 (f a))
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: case h_directed
α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : Countable β
f : β → α → ℝ≥0∞
hf : ∀ (i : β), AEMeasurable (f i) μ
⊢ Directed (fun x1 x2 ↦ x1 ≤ x2) fun s a ↦ ∑ i ∈ s, f i a

Tactic:
intro s t
    use s ∪ t
    constructor
    · exact fun a => Finset.sum_le_sum_of_subset Finset.subset_union_left
    · exact fun a => Finset.sum_le_sum_of_subset Finset.subset_union_right

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

Goal state before:
pp: case e_f
α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
hf : Measurable f
⊢ (fun a ↦ r * f a) = fun a ↦ ⨆ n, (const α r * eapprox f n) a

Tactic:
funext a

Goal state after:
case e_f
α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
hf : Measurable f
a : α
⊢ r * f a = ⨆ n, (const α r * eapprox f n) a
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
    refine (h _ ?_).1
    exact Nat.le_add_left _ _

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

Goal state before:
pp: case refine_2
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)
⊢ ⨆ (_ : SigmaFinite (μ.restrict (μ.sigmaFiniteSetWRT' ν ∪ s))), ν (μ.sigmaFiniteSetWRT' ν ∪ s) ≤
    ⨆ s, ⨆ (_ : MeasurableSet s), ⨆ (_ : SigmaFinite (μ.restrict s)), ν s

Tactic:
· exact le_iSup₂ (f := fun s _ ↦ ⨆ (_ : SigmaFinite (μ.restrict _)), ν s)
        (μ.sigmaFiniteSetWRT' ν ∪ s) (measurableSet_sigmaFiniteSetWRT'.union hs)

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

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
s : Set α
inst✝ : IsFiniteMeasure ν
hs_subset : s ⊆ (μ.sigmaFiniteSetWRT' ν)ᶜ
hνs : ν s ≠ 0
⊢ ⨅ t, ⨅ (_ : s ⊆ t), ⨅ (_ : MeasurableSet t), μ t = ∞

Tactic:
simp_rw [iInf_eq_top]

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
s : Set α
inst✝ : IsFiniteMeasure ν
hs_subset : s ⊆ (μ.sigmaFiniteSetWRT' ν)ᶜ
hνs : ν s ≠ 0
⊢ ∀ (i : Set α), s ⊆ i → MeasurableSet i → μ i = ∞
Module: Mathlib.MeasureTheory.Measure.Decomposition.Exhaustion

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
s : Set α
inst✝ : IsFiniteMeasure ν
hs_subset : s ⊆ (μ.sigmaFiniteSetWRT' ν)ᶜ
hνs : ν s ≠ 0
⊢ ∀ t ⊆ (μ.sigmaFiniteSetWRT' ν)ᶜ, s ⊆ t → MeasurableSet t → μ t = ∞

Tactic:
intro t ht_subset hst ht

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ ν : Measure α
s : Set α
inst✝ : IsFiniteMeasure ν
hs_subset : s ⊆ (μ.sigmaFiniteSetWRT' ν)ᶜ
hνs : ν s ≠ 0
t : Set α
ht_subset : t ⊆ (μ.sigmaFiniteSetWRT' ν)ᶜ
hst : s ⊆ t
ht : MeasurableSet t
⊢ μ t = ∞
Module: Mathlib.Topology.Perfect

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
C : Set α
hC : Preperfect C
x : α
hx : x ∈ closure[inst✝] C
h : x ∈ C
⊢ AccPt x (𝓟 C)

Tactic:
exact hC _ h

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

Goal state before:
pp: α : Type u_1
β : Type u_2
m0 : MeasurableSpace α
μ : Measure α
f : α → β
inst✝² : Zero β
inst✝¹ : TopologicalSpace β
inst✝ : T2Space β
fs : ℕ → α →ₛ β
hT_lt_top : ∀ (n : ℕ), μ (support ⇑(fs n)) < ∞
h_approx : ∀ (x : α), Tendsto (fun n ↦ (fs n) x) atTop (𝓝 (f x))
T : ℕ → Set α := fun n ↦ support ⇑(fs n)
hT_meas : ∀ (n : ℕ), MeasurableSet (T n)
t : Set α := ⋃ n, T n
n : ℕ
x : α
hxt : x ∈ tᶜ
⊢ (fs n) x = 0

Tactic:
rw [Set.mem_compl_iff, Set.mem_iUnion, not_exists] at hxt

Goal state after:
α : Type u_1
β : Type u_2
m0 : MeasurableSpace α
μ : Measure α
f : α → β
inst✝² : Zero β
inst✝¹ : TopologicalSpace β
inst✝ : T2Space β
fs : ℕ → α →ₛ β
hT_lt_top : ∀ (n : ℕ), μ (support ⇑(fs n)) < ∞
h_approx : ∀ (x : α), Tendsto (fun n ↦ (fs n) x) atTop (𝓝 (f x))
T : ℕ → Set α := fun n ↦ support ⇑(fs n)
hT_meas : ∀ (n : ℕ), MeasurableSet (T n)
t : Set α := ⋃ n, T n
n : ℕ
x : α
hxt : ∀ (x_1 : ℕ), x ∉ T x_1
⊢ (fs n) x = 0
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
β : Type u_2
m0 : MeasurableSpace α
μ : Measure α
f : α → β
inst✝² : TopologicalSpace β
inst✝¹ : SubtractionMonoid β
inst✝ : ContinuousNeg β
hf : FinStronglyMeasurable f μ
n : ℕ
⊢ μ (support ⇑(hf.approx n)) < ∞

Tactic:
exact hf.fin_support_approx n

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

Goal state before:
pp: case refine_2
X : Type u
Y : Type v
Z : Type w
inst✝² : MetricSpace X
inst✝¹ : MetricSpace Y
inst✝ : Nonempty Z
Φ : Z → X
Ψ : Z → Y
ε : ℝ
x : X
y z : Y
p : Z
⊢ dist x (Φ p) + dist z (Ψ p) ≤ dist x (Φ p) + dist y (Ψ p) + dist y z

Tactic:
linarith [dist_triangle_left z (Ψ p) y]

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

Goal state before:
pp: case mpr
E : ℕ → Type u_1
α : Type u_2
inst✝ : PseudoMetricSpace α
f : ((n : ℕ) → E n) → α
⊢ (∀ (x y : (n : ℕ) → E n) (n : ℕ), y ∈ cylinder x n → dist (f x) (f y) ≤ (1 / 2) ^ n) →
    ∀ (x y : (n : ℕ) → E n), dist (f x) (f y) ≤ dist x y

Tactic:
intro H x y
    rcases eq_or_ne x y with (rfl | hne)
    · simp [PiNat.dist_nonneg]
    rw [dist_eq_of_ne hne]
    apply H x y (firstDiff x y)
    rw [firstDiff_comm]
    exact mem_cylinder_firstDiff _ _

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

Goal state before:
pp: E : ℕ → Type u_1
inst✝¹ : (n : ℕ) → TopologicalSpace (E n)
inst✝ : ∀ (n : ℕ), DiscreteTopology (E n)
s : Set ((n : ℕ) → E n)
hs : IsClosed[Pi.topologicalSpace] s
x y : (n : ℕ) → E n
hx : x ∉ s
hy : y ∈ s
⊢ firstDiff x y < shortestPrefixDiff x s

Tactic:
by
  have A := exists_disjoint_cylinder hs hx
  rw [shortestPrefixDiff, dif_pos A]
  classical
  have B := Nat.find_spec A
  contrapose! B
  rw [not_disjoint_iff_nonempty_inter]
  refine ⟨y, hy, ?_⟩
  rw [mem_cylinder_comm]
  exact cylinder_anti y B (mem_cylinder_firstDiff x y)

Goal state after:
Module: Mathlib.Dynamics.Ergodic.MeasurePreserving

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : MeasurableSpace α
inst✝ : MeasurableSpace β
μa : Measure α
μb : Measure β
f : α → β
ga : α → α
gb : β → β
hfm : MeasurePreserving f μa μb
hga : MeasurePreserving ga μa μa
hf : Semiconj f ga gb
hgb : Measurable gb
⊢ MeasurePreserving gb μb μb

Tactic:
by
  have := hf.comp_eq ▸ hfm.comp hga |>.map_of_comp hgb hfm.measurable
  rwa [hfm.map_eq] at this

Goal state after:
Module: Mathlib.Dynamics.Ergodic.MeasurePreserving

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
inst✝³ : MeasurableSpace α
inst✝² : MeasurableSpace β
inst✝¹ : MeasurableSpace γ
μa : Measure α
μb : Measure β
inst✝ : MeasurableSingletonClass γ
f : α → β
hf : MeasurePreserving f μa μb
g : β → γ
hg : NullMeasurable g μb
s : Set γ
hs : s.Subsingleton
⊢ s ∈ Filter.map (g ∘ f) (ae μa) ↔ s ∈ Filter.map g (ae μb)

Tactic:
simp only [Filter.mem_map, mem_ae_iff, ← hf.measure_preimage (hg hs.measurableSet).compl,
      preimage_comp, preimage_compl]

Goal state after:
Module: Mathlib.Dynamics.Ergodic.MeasurePreserving

Goal state before:
pp: case succ
α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
f : α → α
s : Set α
hf : MeasurePreserving f μ μ
n : ℕ
ih : μ (s ∆ (f^[n] ⁻¹' s)) ≤ n • μ (s ∆ (f ⁻¹' s))
hs : NullMeasurableSet (s ∆ (f ⁻¹' s)) μ
⊢ μ (s ∆ (f^[n] ⁻¹' s)) + μ ((f^[n] ⁻¹' s) ∆ (f^[n + 1] ⁻¹' s)) ≤ μ (s ∆ (f^[n] ⁻¹' s)) + μ (s ∆ (f ⁻¹' s))

Tactic:
rw [iterate_succ', preimage_comp, ← preimage_symmDiff, (hf.iterate n).measure_preimage hs]

Goal state after:
Module: Mathlib.Dynamics.Ergodic.MeasurePreserving

Goal state before:
pp: α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
f : α → α
s : Set α
hf : MeasurePreserving f μ μ
hs : NullMeasurableSet s μ
n : ℕ
hvol : μ univ < ↑n * μ s
A : ∀ (m : ℕ), NullMeasurableSet (f^[m] ⁻¹' s) μ
B : ∀ (m : ℕ), μ (f^[m] ⁻¹' s) = μ s
⊢ μ univ < ∑ m ∈ Finset.range n, μ (f^[m] ⁻¹' s)

Tactic:
simpa [B]

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

Goal state before:
pp: case refine_2
α : Type u_1
m0 : MeasurableSpace α
ν : Measure α
ι : Type u_2
inst✝ : Countable ι
μ : ι → Measure α
s : ι → Set α
hsm : ∀ (i : ι), MeasurableSet (s i)
hsμ : ∀ (i : ι), (μ i) (s i) = 0
hsν : ∀ (i : ι), ν (s i)ᶜ = 0
⊢ ν (⋂ i, s i)ᶜ = 0

Tactic:
compl_iInter,

Goal state after:
case refine_2
α : Type u_1
m0 : MeasurableSpace α
ν : Measure α
ι : Type u_2
inst✝ : Countable ι
μ : ι → Measure α
s : ι → Set α
hsm : ∀ (i : ι), MeasurableSet (s i)
hsμ : ∀ (i : ι), (μ i) (s i) = 0
hsν : ∀ (i : ι), ν (s i)ᶜ = 0
⊢ ν (⋃ i, (s i)ᶜ) = 0
Module: Mathlib.Topology.MetricSpace.Perfect

Goal state before:
pp: case refine_3
α : Type u_1
inst✝¹ : MetricSpace α
C : Set α
hC : Perfect C
hnonempty : C.Nonempty
inst✝ : CompleteSpace α
u : ℕ → ℝ≥0∞
upos' : ∀ (n : ℕ), u n ∈ Ioo 0 1
hu : Tendsto u atTop (nhds 0)
upos : ∀ (n : ℕ), 0 < u n
P : Type (max 0 u_1) := { E // Perfect E ∧ E.Nonempty }
C0 C1 : {C : Set α} → Perfect C → C.Nonempty → {ε : ℝ≥0∞} → 0 < ε → Set α
h0 :
  ∀ {C : Set α} (hC : Perfect C) (hnonempty : C.Nonempty) {ε : ℝ≥0∞} (hε : 0 < ε),
    Perfect (C0 hC hnonempty hε) ∧
      (C0 hC hnonempty hε).Nonempty ∧ C0 hC hnonempty hε ⊆ C ∧ ediam (C0 hC hnonempty hε) ≤ ε
h1 :
  ∀ {C : Set α} (hC : Perfect C) (hnonempty : C.Nonempty) {ε : ℝ≥0∞} (hε : 0 < ε),
    Perfect (C1 hC hnonempty hε) ∧
      (C1 hC hnonempty hε).Nonempty ∧ C1 hC hnonempty hε ⊆ C ∧ ediam (C1 hC hnonempty hε) ≤ ε
hdisj :
  ∀ {C : Set α} (hC : Perfect C) (hnonempty : C.Nonempty) {ε : ℝ≥0∞} (hε : 0 < ε),
    Disjoint (C0 hC hnonempty hε) (C1 hC hnonempty hε)
DP : List Bool → P :=
  fun l ↦
    List.rec ⟨C, ⋯⟩
      (fun a l ih ↦ Bool.casesOn (motive := fun t ↦ a = t → P) a (fun h ↦ ⟨C0 ⋯ ⋯ ⋯, ⋯⟩) (fun h ↦ ⟨C1 ⋯ ⋯ ⋯, ⋯⟩) ⋯) l
D : List Bool → Set α := fun l ↦ ↑(DP l)
hanti : ClosureAntitone D
hdiam : VanishingDiam D
hdisj' : CantorScheme.Disjoint D
hdom : ∀ {x : ℕ → Bool}, x ∈ (inducedMap D).fst
x y : ℕ → Bool
hxy : (fun x ↦ (inducedMap D).snd ⟨x, ⋯⟩) x = (fun x ↦ (inducedMap D).snd ⟨x, ⋯⟩) y
⊢ x = y

Tactic:
simpa only [← Subtype.val_inj] using hdisj'.map_injective hxy

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

Goal state before:
pp: case refine_2
α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
h : Disjoint μ ν
ε : ℝ≥0
hε : 0 < ε
h₁ : sInf {m | ∃ t, m = μ t + ν tᶜ} = 0
t : ℕ → Set α
ht₂ : ∀ (n : ℕ), μ (t n) + ν (t n)ᶜ < ↑ε * (1 / 2) ^ n
⊢ ν (⋂ n, t n)ᶜ ≤ 2 * ↑ε

Tactic:
compl_iInter,

Goal state after:
case refine_2
α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
h : Disjoint μ ν
ε : ℝ≥0
hε : 0 < ε
h₁ : sInf {m | ∃ t, m = μ t + ν tᶜ} = 0
t : ℕ → Set α
ht₂ : ∀ (n : ℕ), μ (t n) + ν (t n)ᶜ < ↑ε * (1 / 2) ^ n
⊢ ν (⋃ i, (t i)ᶜ) ≤ 2 * ↑ε
Module: Mathlib.Topology.MetricSpace.PiNat

Goal state before:
pp: α : Type u_2
inst✝³ : MetricSpace α
inst✝² : CompleteSpace α
inst✝¹ : SecondCountableTopology α
inst✝ : Nonempty α
this : MetricSpace (ℕ → ℕ) := metricSpaceNatNat
I0 : 0 < 1 / 2
I1 : 1 / 2 < 1
u : ℕ → α
hu : DenseRange u
s : Set (ℕ → ℕ) := {x | (⋂ n, closedBall (u (x n)) ((1 / 2) ^ n)).Nonempty}
g : ↑s → α := fun x ↦ Set.Nonempty.some ⋯
A : ∀ (x : ↑s) (n : ℕ), dist (g x) (u (↑x n)) ≤ (1 / 2) ^ n
y : ↑s
⊢ ContinuousAt g y

Tactic:
refine continuousAt_of_locally_lipschitz zero_lt_one 4 fun x hxy => ?_

Goal state after:
α : Type u_2
inst✝³ : MetricSpace α
inst✝² : CompleteSpace α
inst✝¹ : SecondCountableTopology α
inst✝ : Nonempty α
this : MetricSpace (ℕ → ℕ) := metricSpaceNatNat
I0 : 0 < 1 / 2
I1 : 1 / 2 < 1
u : ℕ → α
hu : DenseRange u
s : Set (ℕ → ℕ) := {x | (⋂ n, closedBall (u (x n)) ((1 / 2) ^ n)).Nonempty}
g : ↑s → α := fun x ↦ Set.Nonempty.some ⋯
A : ∀ (x : ↑s) (n : ℕ), dist (g x) (u (↑x n)) ≤ (1 / 2) ^ n
y x : ↑s
hxy : dist x y < 1
⊢ dist (g x) (g y) ≤ 4 * dist x y
Module: Mathlib.MeasureTheory.Measure.GiryMonad

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
ι : Type u_3
m : ι → Measure (Measure α)
s : Set α
hs : MeasurableSet s
⊢ (sum m).join s = (sum fun i ↦ (m i).join) s

Tactic:
sum_apply _ hs,

Goal state after:
α : Type u_1
mα : MeasurableSpace α
ι : Type u_3
m : ι → Measure (Measure α)
s : Set α
hs : MeasurableSet s
⊢ (sum m).join s = ∑' (i : ι), (m i).join s
Module: Mathlib.MeasureTheory.Measure.GiryMonad

Goal state before:
pp: α : Type u_1
β : Type u_2
mα : MeasurableSpace α
mβ : MeasurableSpace β
R : Type u_3
inst✝¹ : SMul R ℝ≥0∞
inst✝ : IsScalarTower R ℝ≥0∞ ℝ≥0∞
c : R
m : Measure α
f : α → Measure β
⊢ (c • m).bind f = c • m.bind f

Tactic:
simp_rw [bind, Measure.map_smul, join_smul]

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

Goal state before:
pp: case right
E : ℕ → Type u_1
ι : Type u_2
inst✝¹ : Encodable ι
F : ι → Type u_3
inst✝ : (i : ι) → PseudoEMetricSpace (F i)
i : ι
ε : ℝ≥0∞
hε₀ : 0 < ε
⊢ {a | edist (a.1 i) (a.2 i) < ε} ∈ ⨅ ε, ⨅ (_ : 0 < ε), 𝓟 {p | edist p.1 p.2 < ε}

Tactic:
have : (0 : ℝ≥0∞) < 2⁻¹ ^ encode i := ENNReal.pow_pos (by norm_num) _

Goal state after:
case right
E : ℕ → Type u_1
ι : Type u_2
inst✝¹ : Encodable ι
F : ι → Type u_3
inst✝ : (i : ι) → PseudoEMetricSpace (F i)
i : ι
ε : ℝ≥0∞
hε₀ : 0 < ε
this : 0 < 2⁻¹ ^ encode i
⊢ {a | edist (a.1 i) (a.2 i) < ε} ∈ ⨅ ε, ⨅ (_ : 0 < ε), 𝓟 {p | edist p.1 p.2 < ε}
Module: Mathlib.MeasureTheory.Measure.OpenPos

Goal state before:
pp: X : Type u_1
inst✝⁴ : TopologicalSpace X
m : MeasurableSpace X
inst✝³ : BorelSpace X
Z : Type u_3
inst✝² : TopologicalSpace Z
mZ : MeasurableSpace Z
inst✝¹ : BorelSpace Z
μ : Measure Z
inst✝ : μ.IsOpenPosMeasure
f : X → Z
hf : IsOpenEmbedding f
U : Set X
hU : IsOpen[inst✝⁴] U
Une : U.Nonempty
⊢ (comap f μ) U ≠ 0

Tactic:
rw [hf.measurableEmbedding.comap_apply]

Goal state after:
X : Type u_1
inst✝⁴ : TopologicalSpace X
m : MeasurableSpace X
inst✝³ : BorelSpace X
Z : Type u_3
inst✝² : TopologicalSpace Z
mZ : MeasurableSpace Z
inst✝¹ : BorelSpace Z
μ : Measure Z
inst✝ : μ.IsOpenPosMeasure
f : X → Z
hf : IsOpenEmbedding f
U : Set X
hU : IsOpen[inst✝⁴] U
Une : U.Nonempty
⊢ μ (f '' U) ≠ 0
Module: Mathlib.Topology.MetricSpace.PiNat

Goal state before:
pp: X : Type u_3
inst✝¹ : MetricSpace X
inst✝ : SeparableSpace X
x y : X
hxy : x ≠ y
n : ℕ
hn : {y}ᶜ ∈ comap (distDenseSeq X n) (𝓝 (distDenseSeq X n x))
⊢ ∃ n, distDenseSeq X n x ≠ distDenseSeq X n y

Tactic:
exact ⟨n, fun e ↦ by simp +contextual [e, ← exists_prop, mem_of_mem_nhds] at hn⟩

Goal state after:
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: X : Type u_3
Z : Type u_5
inst✝³ : MeasurableSpace X
inst✝² : StandardBorelSpace X
inst✝¹ : MeasurableSpace Z
f : X → Z
inst✝ : CountablySeparated ↑(range f)
hf : Measurable f
hr : MeasurableSet (range f)
s : Set Z
⊢ MeasurableSet (f ⁻¹' s) ↔ MeasurableSet (s ∩ range f)

Tactic:
rw [hf.measurableSet_preimage_iff_preimage_val, inter_comm,
    ← (MeasurableEmbedding.subtype_coe hr).measurableSet_image, Subtype.image_preimage_coe]

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

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
inst✝² : MeasurableSpace β
ι' : Type u_4
inst✝¹ : Countable ι'
m : Measure α
m' : ι' → Measure β
inst✝ : ∀ (n : ι'), SFinite (m' n)
s : Set (α × β)
hs : MeasurableSet s
M : ∀ (x : α), MeasurableSet (Prod.mk x ⁻¹' s)
⊢ ∫⁻ (x : α), ∑' (i : ι'), (m' i) (Prod.mk x ⁻¹' s) ∂m = ∑' (i : ι'), ∫⁻ (x : α), (m' i) (Prod.mk x ⁻¹' s) ∂m

Tactic:
lintegral_tsum (fun i ↦ (measurable_measure_prodMk_left hs).aemeasurable)

Goal state after:
α : Type u_1
β : Type u_2
inst✝³ : MeasurableSpace α
inst✝² : MeasurableSpace β
ι' : Type u_4
inst✝¹ : Countable ι'
m : Measure α
m' : ι' → Measure β
inst✝ : ∀ (n : ι'), SFinite (m' n)
s : Set (α × β)
hs : MeasurableSet s
M : ∀ (x : α), MeasurableSet (Prod.mk x ⁻¹' s)
⊢ ∑' (i : ι'), ∫⁻ (a : α), (m' i) (Prod.mk a ⁻¹' s) ∂m = ∑' (i : ι'), ∫⁻ (x : α), (m' i) (Prod.mk x ⁻¹' s) ∂m
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: γ : Type u_3
β : Type u_4
inst✝⁵ : TopologicalSpace γ
inst✝⁴ : PolishSpace γ
inst✝³ : TopologicalSpace β
inst✝² : T2Space β
inst✝¹ : MeasurableSpace β
inst✝ : OpensMeasurableSpace β
f : γ → β
f_cont : Continuous[inst✝⁵, inst✝³] f
f_inj : Injective f
this✝ : UpgradedIsCompletelyMetrizableSpace γ := upgradeIsCompletelyMetrizable γ
b : Set (Set γ)
b_count : b.Countable
b_nonempty : ∅ ∉ b
hb : IsTopologicalBasis b
this : Encodable ↑b
A : Type (max 0 u_3) := { p // Disjoint ↑p.1 ↑p.2 }
q : A → Set β
hq1 : ∀ (p : A), f '' ↑(↑p).1 ⊆ q p
hq2 : ∀ (p : A), Disjoint (f '' ↑(↑p).2) (q p)
q_meas : ∀ (p : A), MeasurableSet (q p)
E : ↑b → Set β := fun s ↦ closure[inst✝³] (f '' ↑s) ∩ ⋂ t, ⋂ (ht : Disjoint ↑s ↑t), q ⟨(s, t), ht⟩ \ q ⟨(t, s), ⋯⟩
⊢ MeasurableSet (range f)

Tactic:
obtain ⟨u, u_anti, u_pos, u_lim⟩ :
      ∃ u : ℕ → ℝ, StrictAnti u ∧ (∀ n : ℕ, 0 < u n) ∧ Tendsto u atTop (𝓝 0) :=
    exists_seq_strictAnti_tendsto (0 : ℝ)

Goal state after:
γ : Type u_3
β : Type u_4
inst✝⁵ : TopologicalSpace γ
inst✝⁴ : PolishSpace γ
inst✝³ : TopologicalSpace β
inst✝² : T2Space β
inst✝¹ : MeasurableSpace β
inst✝ : OpensMeasurableSpace β
f : γ → β
f_cont : Continuous[inst✝⁵, inst✝³] f
f_inj : Injective f
this✝ : UpgradedIsCompletelyMetrizableSpace γ := upgradeIsCompletelyMetrizable γ
b : Set (Set γ)
b_count : b.Countable
b_nonempty : ∅ ∉ b
hb : IsTopologicalBasis b
this : Encodable ↑b
A : Type (max 0 u_3) := { p // Disjoint ↑p.1 ↑p.2 }
q : A → Set β
hq1 : ∀ (p : A), f '' ↑(↑p).1 ⊆ q p
hq2 : ∀ (p : A), Disjoint (f '' ↑(↑p).2) (q p)
q_meas : ∀ (p : A), MeasurableSet (q p)
E : ↑b → Set β := fun s ↦ closure[inst✝³] (f '' ↑s) ∩ ⋂ t, ⋂ (ht : Disjoint ↑s ↑t), q ⟨(s, t), ht⟩ \ q ⟨(t, s), ⋯⟩
u : ℕ → ℝ
u_anti : StrictAnti u
u_pos : ∀ (n : ℕ), 0 < u n
u_lim : Tendsto u atTop (𝓝 0)
⊢ MeasurableSet (range f)
Module: Mathlib.GroupTheory.Complement

Goal state before:
pp: G : Type u_1
inst✝ : Group G
H : Subgroup G
T : Set G
hHT : IsComplement (↑H) T
g : G
⊢ RightCosetEquivalence (↑H) g ↑(hHT.equiv g).2

Tactic:
rw [RightCosetEquivalence, rightCoset_eq_iff, equiv_snd_eq_inv_mul]

Goal state after:
G : Type u_1
inst✝ : Group G
H : Subgroup G
T : Set G
hHT : IsComplement (↑H) T
g : G
⊢ (↑(hHT.equiv g).1)⁻¹ * g * g⁻¹ ∈ H