mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.MeasureTheory.Constructions.BorelSpace.Order

Goal state before:
pp: 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
A : MeasurableSet {b | BddAbove (range fun i ↦ f i b)}
⊢ Measurable fun b ↦ ⨆ i, f i b

Tactic:
have : Measurable (fun (_b : δ) ↦ sSup (∅ : Set α)) := measurable_const

Goal state after:
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
A : MeasurableSet {b | BddAbove (range fun i ↦ f i b)}
this : Measurable fun _b ↦ sSup ∅
⊢ Measurable fun b ↦ ⨆ i, f i b
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.AEStronglyMeasurable

Goal state before:
pp: α : Type u_5
β : Type u_6
inst✝² : TopologicalSpace β
inst✝¹ : PseudoMetrizableSpace β
mb : MeasurableSpace β
inst✝ : BorelSpace β
m : MeasurableSpace α
μ : Measure α
f : α → β
s : Set β
hs : MeasurableSet s
h_nonempty : s.Nonempty
h_mem : ∀ᵐ (x : α) ∂μ, f x ∈ s
f' : α → β
hf' : StronglyMeasurable f'
hff' : f =ᵐ[μ] f'
x : α
hx : f x ∈ s
⊢ f x = f' x → f' x = (f' ⁻¹' s).piecewise f' (fun x ↦ h_nonempty.some) x

Tactic:
hx'

Goal state after:
α : Type u_5
β : Type u_6
inst✝² : TopologicalSpace β
inst✝¹ : PseudoMetrizableSpace β
mb : MeasurableSpace β
inst✝ : BorelSpace β
m : MeasurableSpace α
μ : Measure α
f : α → β
s : Set β
hs : MeasurableSet s
h_nonempty : s.Nonempty
h_mem : ∀ᵐ (x : α) ∂μ, f x ∈ s
f' : α → β
hf' : StronglyMeasurable f'
hff' : f =ᵐ[μ] f'
x : α
hx : f x ∈ s
hx' : f x = f' x
⊢ f' x = (f' ⁻¹' s).piecewise f' (fun x ↦ h_nonempty.some) x
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
ι : Type u_4
f : α → ℝ≥0∞
μ : ι → Measure α
⊢ ∫⁻ (a : α), f a ∂Measure.sum μ = ⨆ s, ∑ i ∈ s, ∫⁻ (a : α), f a ∂μ i

Tactic:
← lintegral_finsetSum_measure,

Goal state after:
α : Type u_1
m : MeasurableSpace α
ι : Type u_4
f : α → ℝ≥0∞
μ : ι → Measure α
⊢ ∫⁻ (a : α), f a ∂Measure.sum μ = ⨆ s, ∫⁻ (a : α), f a ∂∑ i ∈ s, μ i
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Sub

Goal state before:
pp: α : Type u_1
inst✝ : MeasurableSpace α
μ : Measure α
f : ℕ → α → ℝ≥0∞
h_meas : ∀ (n : ℕ), AEMeasurable (f n) μ
h_anti : ∀ᵐ (a : α) ∂μ, Antitone fun i ↦ f i a
h_fin : ∫⁻ (a : α), f 0 a ∂μ ≠ ∞
p : α → (ℕ → ℝ≥0∞) → Prop := fun x f' ↦ Antitone f'
hp : ∀ᵐ (x : α) ∂μ, p x fun i ↦ f i x
h_ae_seq_mono : Antitone (aeSeq h_meas p)
⊢ ∫⁻ (a : α), aeSeq h_meas p 0 a ∂μ ≠ ∞

Tactic:
· rwa [lintegral_congr_ae (aeSeq.aeSeq_n_eq_fun_n_ae h_meas hp 0)]

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), (⨆ n, (eapprox f n) a) + ⨆ n, (eapprox g n) a ∂μ = ∫⁻ (a : α), ⨆ n, (⇑(eapprox f n) + ⇑(eapprox g n)) a ∂μ

Tactic:
congr; funext a
      rw [ENNReal.iSup_add_iSup_of_monotone]
      · simp only [Pi.add_apply]
      · intro i j h
        exact monotone_eapprox _ h a
      · intro i j h
        exact monotone_eapprox _ h a

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), ⨆ n, (⇑(eapprox f n) + ⇑(eapprox g n)) a ∂μ = ⨆ n, (eapprox f n).lintegral μ + (eapprox g n).lintegral μ

Tactic:
rw [lintegral_iSup]

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

case hf
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hf : Measurable f
hg : Measurable g
⊢ ∀ (n : ℕ), Measurable (⇑(eapprox f n) + ⇑(eapprox g n))

case h_mono
α : Type u_1
m : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hf : Measurable f
hg : Measurable g
⊢ Monotone fun n ↦ ⇑(eapprox f n) + ⇑(eapprox g n)
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∞
hf : Measurable f
⊢ ∫⁻ (a : α), ⨆ n, (const α r * eapprox f n) a ∂μ = ⨆ n, r * (eapprox f n).lintegral μ

Tactic:
rw [lintegral_iSup]

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
hf : Measurable f
⊢ ⨆ n, ∫⁻ (a : α), (const α r * eapprox f n) a ∂μ = ⨆ n, r * (eapprox f n).lintegral μ

case hf
α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
hf : Measurable f
⊢ ∀ (n : ℕ), Measurable ⇑(const α r * eapprox f n)

case h_mono
α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
hf : Measurable f
⊢ Monotone fun n ↦ ⇑(const α r * eapprox f n)
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∞
s : α →ₛ ℝ≥0∞
⊢ r * ⨆ (_ : ⇑s ≤ fun a ↦ f a), s.lintegral μ ≤ ∫⁻ (a : α), r * f a ∂μ

Tactic:
ENNReal.mul_iSup,

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
r : ℝ≥0∞
f : α → ℝ≥0∞
s : α →ₛ ℝ≥0∞
⊢ ⨆ (_ : ⇑s ≤ fun a ↦ f a), r * s.lintegral μ ≤ ∫⁻ (a : α), r * f a ∂μ
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
this : {x}ᶜ ∩ C = C
⊢ (𝓝 x ⊓ 𝓟 C).NeBot

Tactic:
rw [closure_eq_cluster_pts] at hx

Goal state after:
α : Type u_1
inst✝ : TopologicalSpace α
C : Set α
hC : Preperfect C
x : α
hx : x ∈ {a | ClusterPt a (𝓟 C)}
h : x ∉ C
this : {x}ᶜ ∩ C = C
⊢ (𝓝 x ⊓ 𝓟 C).NeBot
Module: Mathlib.Topology.Perfect

Goal state before:
pp: α : Type u_1
inst✝³ : TopologicalSpace α
C : Set α
inst✝² : T1Space α
inst✝¹ : ConnectedSpace α
inst✝ : Nontrivial α
⊢ PerfectSpace α

Tactic:
by
  constructor
  apply isPreconnected_univ.preperfect_of_nontrivial
  rw [Set.nontrivial_univ_iff]
  infer_instance

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

Goal state before:
pp: α : Type u_2
mα : MeasurableSpace α
f : ℕ → α → ℝ≥0∞
F : α → ℝ≥0∞
μ : Measure α
hf_meas : ∀ (n : ℕ), AEMeasurable (f n) μ
hf_tendsto : Tendsto (fun i ↦ ∫⁻ (a : α), f i a ∂μ) atTop (𝓝 (∫⁻ (a : α), F a ∂μ))
hf_mono : ∀ᵐ (a : α) ∂μ, Antitone fun i ↦ f i a
h_bound : ∀ᵐ (a : α) ∂μ, ∀ (i : ℕ), F a ≤ f i a
h0 : ∫⁻ (a : α), f 0 a ∂μ ≠ ∞
h_int_finite : ∫⁻ (a : α), F a ∂μ ≠ ∞
⊢ ∀ᵐ (a : α) ∂μ, ∃ l, Tendsto (fun i ↦ f i a) atTop (𝓝 l)

Tactic:
filter_upwards [hf_mono] with a h_mono

Goal state after:
α : Type u_2
mα : MeasurableSpace α
f : ℕ → α → ℝ≥0∞
F : α → ℝ≥0∞
μ : Measure α
hf_meas : ∀ (n : ℕ), AEMeasurable (f n) μ
hf_tendsto : Tendsto (fun i ↦ ∫⁻ (a : α), f i a ∂μ) atTop (𝓝 (∫⁻ (a : α), F a ∂μ))
hf_mono : ∀ᵐ (a : α) ∂μ, Antitone fun i ↦ f i a
h_bound : ∀ᵐ (a : α) ∂μ, ∀ (i : ℕ), F a ≤ f i a
h0 : ∫⁻ (a : α), f 0 a ∂μ ≠ ∞
h_int_finite : ∫⁻ (a : α), F a ∂μ ≠ ∞
a : α
h_mono : Antitone fun i ↦ f i a
⊢ ∃ l, Tendsto (fun i ↦ f i a) atTop (𝓝 l)
Module: Mathlib.Topology.UnitInterval

Goal state before:
pp: x : ↑I
⊢ Subtype.val ⁻¹' Iio ↑x = Ico 0 x

Tactic:
rw [preimage_subtype_val_Iio]

Goal state after:
x : ↑I
⊢ Iio x = Ico 0 x
Module: Mathlib.Topology.MetricSpace.Polish

Goal state before:
pp: α : Type u_1
t : TopologicalSpace α
inst✝ : PolishSpace α
s : ℕ → Set α
hs : ∀ (n : ℕ), IsClopenable (s n)
⊢ IsClopenable (⋃ n, s n)

Tactic:
choose m mt m_polish _ m_open using hs

Goal state after:
α : Type u_1
t : TopologicalSpace α
inst✝ : PolishSpace α
s : ℕ → Set α
m : ℕ → TopologicalSpace α
mt : ∀ (n : ℕ), m n ≤ t
m_polish : ∀ (n : ℕ), PolishSpace α
h✝ : ∀ (n : ℕ), IsClosed[m n] (s n)
m_open : ∀ (n : ℕ), IsOpen[m n] (s n)
⊢ IsClopenable (⋃ n, s n)
Module: Mathlib.Topology.MetricSpace.PiNat

Goal state before:
pp: case pos
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
hne : s.Nonempty
f : ((n : ℕ) → E n) → (n : ℕ) → E n := fun x ↦ if x ∈ s then x else ⋯.some
fs : ∀ x ∈ s, f x = x
x y : (n : ℕ) → E n
hxy : x ≠ y
hfxfy : x ≠ f y
I2 : cylinder x (firstDiff x y) = cylinder y (firstDiff x y)
xs : x ∈ s
ys : y ∈ s
⊢ firstDiff x y ≤ firstDiff x (f y)

pp: case neg
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
hne : s.Nonempty
f : ((n : ℕ) → E n) → (n : ℕ) → E n := fun x ↦ if x ∈ s then x else ⋯.some
fs : ∀ x ∈ s, f x = x
x y : (n : ℕ) → E n
hxy : x ≠ y
hfxfy : x ≠ f y
I2 : cylinder x (firstDiff x y) = cylinder y (firstDiff x y)
xs : x ∈ s
ys : y ∉ s
⊢ firstDiff x y ≤ firstDiff x (f y)

Tactic:
· rw [fs y ys]

Goal state after:
case neg
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
hne : s.Nonempty
f : ((n : ℕ) → E n) → (n : ℕ) → E n := fun x ↦ if x ∈ s then x else ⋯.some
fs : ∀ x ∈ s, f x = x
x y : (n : ℕ) → E n
hxy : x ≠ y
hfxfy : x ≠ f y
I2 : cylinder x (firstDiff x y) = cylinder y (firstDiff x y)
xs : x ∈ s
ys : y ∉ s
⊢ firstDiff x y ≤ firstDiff x (f y)
Module: Mathlib.MeasureTheory.Measure.MutuallySingular

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ ν₁ ν₂ : Measure α
h : μ ≪ ν₁ + ν₂
h_ms : μ ⟂ₘ ν₂
s : Set α
hs : MeasurableSet s
hs_zero : ν₁ s = 0
t : Set α := h_ms.nullSet
ht : MeasurableSet t
htμ : μ t = 0
htν₂ : ν₂ tᶜ = 0
this : μ s = μ (s ∩ tᶜ)
⊢ μ (s ∩ tᶜ) = 0

Tactic:
refine h ?_

Goal state after:
α : Type u_1
m0 : MeasurableSpace α
μ ν₁ ν₂ : Measure α
h : μ ≪ ν₁ + ν₂
h_ms : μ ⟂ₘ ν₂
s : Set α
hs : MeasurableSet s
hs_zero : ν₁ s = 0
t : Set α := h_ms.nullSet
ht : MeasurableSet t
htμ : μ t = 0
htν₂ : ν₂ tᶜ = 0
this : μ s = μ (s ∩ tᶜ)
⊢ (ν₁ + ν₂) (s ∩ tᶜ) = 0
Module: Mathlib.MeasureTheory.Measure.Typeclasses.Probability

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
s : Set α
inst✝ : IsProbabilityMeasure μ
hs : NullMeasurableSet s μ
⊢ 1 ≤ μ s ↔ μ s = 1

Tactic:
one_le_prob_iff

Goal state after:
α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
s : Set α
inst✝ : IsProbabilityMeasure μ
hs : NullMeasurableSet s μ
⊢ μ s = 1 ↔ μ s = 1
Module: Mathlib.MeasureTheory.Measure.Dirac

Goal state before:
pp: δ : Type u_3
ι : Type u_4
mδ : MeasurableSpace δ
c : ι → ℝ
d : ι → δ
h1 : ∀ (i : ι), 0 ≤ c i
h2 : HasSum c 1
⊢ HasSum (fun i ↦ (c i).toNNReal) 1

Tactic:
simpa using h2.toNNReal h1

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

Goal state before:
pp: α : Type u_1
inst✝¹ : MeasurableSpace α
inst✝ : MeasurableSpace.SeparatesPoints α
x y : α
x_ne_y : (fun x ↦ dirac x) x = (fun x ↦ dirac x) y
⊢ x = y

Tactic:
← dirac_eq_dirac_iff

Goal state after:
α : Type u_1
inst✝¹ : MeasurableSpace α
inst✝ : MeasurableSpace.SeparatesPoints α
x y : α
x_ne_y : (fun x ↦ dirac x) x = (fun x ↦ dirac x) y
⊢ dirac x = dirac y
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: case refine_2
ι : Type u_2
inst✝¹ : Countable ι
α : Type u_3
inst✝ : MeasurableSpace α
s t : ι → Set α
u : ι → ι → Set α
hsu : ∀ (m n : ι), s m ⊆ u m n
htu : ∀ (m n : ι), Disjoint (t n) (u m n)
hu : ∀ (m n : ι), MeasurableSet (u m n)
⊢ Disjoint (⋃ m, t m) (⋃ m, ⋂ n, u m n)

Tactic:
simp_rw [disjoint_iUnion_left, disjoint_iUnion_right]
    intro n m
    apply Disjoint.mono_right _ (htu m n)
    apply iInter_subset

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

Goal state before:
pp: ι : Type u_2
inst✝¹ : Encodable ι
F : ι → Type u_3
inst✝ : (i : ι) → PseudoMetricSpace (F i)
x y : (i : ι) → F i
⊢ Summable fun i ↦ 2⁻¹ ^ encode i

Tactic:
by
    simpa [one_div] using summable_geometric_two_encode

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

Goal state before:
pp: α : Type u_1
inst✝² : PseudoMetricSpace α
inst✝¹ : MeasurableSpace α
μ : Measure α
inst✝ : IsUnifLocDoublingMeasure μ
K : ℝ
⊢ ∀ᶠ (r : ℝ) in 𝓝[>] 0, ∀ (x : α), μ (closedBall x (K * r)) ≤ ↑(scalingConstantOf μ K) * μ (closedBall x r)

Tactic:
by
  filter_upwards [Classical.choose_spec
      (exists_eventually_forall_measure_closedBall_le_mul μ K)] with r hr x
  grw [hr x K le_rfl, scalingConstantOf, ← le_max_left]

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

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
p q : Set α → Prop
ν : Measure α
hμ : μ.InnerRegularWRT p q
hν : ν.InnerRegularWRT p q
hμν : ∀ (U : Set α), p U → μ U = ν U
U : Set α
hU : q U
⊢ μ U = ν U

Tactic:
hμ.measure_eq_iSup hU,

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
p q : Set α → Prop
ν : Measure α
hμ : μ.InnerRegularWRT p q
hν : ν.InnerRegularWRT p q
hμν : ∀ (U : Set α), p U → μ U = ν U
U : Set α
hU : q U
⊢ ⨆ K, ⨆ (_ : K ⊆ U), ⨆ (_ : p K), μ K = ν U
Module: Mathlib.GroupTheory.Complement

Goal state before:
pp: case mpr.py₁
G : Type u_1
inst✝ : Group G
H : Subgroup G
T : Set G
hHT : IsComplement (↑H) T
g₁ g₂ : G
h : g₂ * g₁⁻¹ ∈ H
⊢ g₁ * (↑(hHT.equiv g₁).2)⁻¹ ∈ ↑H

Tactic:
rw [equiv_snd_eq_inv_mul]; simp

Goal state after:
Module: Mathlib.GroupTheory.Complement

Goal state before:
pp: G : Type u_1
inst✝¹ : Group G
H : Subgroup G
α : Type u_2
inst✝ : MulAction G α
a : α
h1 : ∀ (h : ↥H), h • a = a → h = 1
h2 : ∀ (g : G), ∃ h, h • g • a = a
g : G
h : ↥H
hh : h • g • a = a
⊢ (↑h * g) • a = a

Tactic:
mul_smul

Goal state after:
G : Type u_1
inst✝¹ : Group G
H : Subgroup G
α : Type u_2
inst✝ : MulAction G α
a : α
h1 : ∀ (h : ↥H), h • a = a → h = 1
h2 : ∀ (g : G), ∃ h, h • g • a = a
g : G
h : ↥H
hh : h • g • a = a
⊢ ↑h • g • a = a
Module: Mathlib.MeasureTheory.Measure.Regular

Goal state before:
pp: α : Type u_1
inst✝² : MeasurableSpace α
inst✝¹ : TopologicalSpace α
inst✝ : OpensMeasurableSpace α
μ : Measure α
s : ℕ → Set α
h : ∀ (n : ℕ), (μ.restrict (s n)).OuterRegular
h' : ∀ (n : ℕ), IsOpen[inst✝¹] (s n)
h'' : univ ⊆ ⋃ n, s n
r : ℝ≥0∞
hm : ∀ (n : ℕ), MeasurableSet (s n)
A : ℕ → Set α
hAm : ∀ (n : ℕ), MeasurableSet (A n)
hAs : ∀ (n : ℕ), A n ⊆ s n
hAd : Pairwise (Disjoint on A)
hA : MeasurableSet (⋃ n, A n)
hr : r > μ (⋃ n, A n)
HA : μ (⋃ n, A n) < ∞
δ : ℕ → ℝ≥0∞
δ0 : ∀ (i : ℕ), 0 < δ i
hδε : μ (⋃ n, A n) + ∑' (i : ℕ), δ i < r
this : ∀ (n : ℕ), ∃ U ⊇ A n, IsOpen[inst✝¹] U ∧ μ U < μ (A n) + δ n
⊢ ∃ U ⊇ ⋃ n, A n, IsOpen[inst✝¹] U ∧ μ U < r

Tactic:
choose U hAU hUo hU using this

Goal state after:
α : Type u_1
inst✝² : MeasurableSpace α
inst✝¹ : TopologicalSpace α
inst✝ : OpensMeasurableSpace α
μ : Measure α
s : ℕ → Set α
h : ∀ (n : ℕ), (μ.restrict (s n)).OuterRegular
h' : ∀ (n : ℕ), IsOpen[inst✝¹] (s n)
h'' : univ ⊆ ⋃ n, s n
r : ℝ≥0∞
hm : ∀ (n : ℕ), MeasurableSet (s n)
A : ℕ → Set α
hAm : ∀ (n : ℕ), MeasurableSet (A n)
hAs : ∀ (n : ℕ), A n ⊆ s n
hAd : Pairwise (Disjoint on A)
hA : MeasurableSet (⋃ n, A n)
hr : r > μ (⋃ n, A n)
HA : μ (⋃ n, A n) < ∞
δ : ℕ → ℝ≥0∞
δ0 : ∀ (i : ℕ), 0 < δ i
hδε : μ (⋃ n, A n) + ∑' (i : ℕ), δ i < r
U : ℕ → Set α
hAU : ∀ (n : ℕ), U n ⊇ A n
hUo : ∀ (n : ℕ), IsOpen[inst✝¹] (U n)
hU : ∀ (n : ℕ), μ (U n) < μ (A n) + δ n
⊢ ∃ U ⊇ ⋃ n, A n, IsOpen[inst✝¹] U ∧ μ U < r
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: γ : Type u_3
s : Set γ
tγ : TopologicalSpace γ
inst✝² : PolishSpace γ
inst✝¹ : MeasurableSpace γ
inst✝ : BorelSpace γ
⊢ IsClopenable s ↔ MeasurableSet s

Tactic:
refine ⟨fun hs => ?_, fun hs => hs.isClopenable⟩

Goal state after:
γ : Type u_3
s : Set γ
tγ : TopologicalSpace γ
inst✝² : PolishSpace γ
inst✝¹ : MeasurableSpace γ
inst✝ : BorelSpace γ
hs : IsClopenable s
⊢ MeasurableSet s
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: α : Type u_6
β : Type u_7
t : Set α
g : α → β
inst✝¹¹ : TopologicalSpace α
inst✝¹⁰ : MeasurableSpace α
inst✝⁹ : BorelSpace α
inst✝⁸ : LinearOrder α
inst✝⁷ : OrderTopology α
inst✝⁶ : PolishSpace α
inst✝⁵ : TopologicalSpace β
inst✝⁴ : MeasurableSpace β
inst✝³ : BorelSpace β
inst✝² : LinearOrder β
inst✝¹ : OrderTopology β
inst✝ : SecondCountableTopology β
ht : MeasurableSet t
hg : MonotoneOn g t
t' : Set α := {x | x ∈ t ∧ ¬ContinuousWithinAt g t x}
ht' : t'.Countable
⊢ g '' t = g '' (t \ t') ∪ g '' t'

Tactic:
rw [← image_union]

Goal state after:
α : Type u_6
β : Type u_7
t : Set α
g : α → β
inst✝¹¹ : TopologicalSpace α
inst✝¹⁰ : MeasurableSpace α
inst✝⁹ : BorelSpace α
inst✝⁸ : LinearOrder α
inst✝⁷ : OrderTopology α
inst✝⁶ : PolishSpace α
inst✝⁵ : TopologicalSpace β
inst✝⁴ : MeasurableSpace β
inst✝³ : BorelSpace β
inst✝² : LinearOrder β
inst✝¹ : OrderTopology β
inst✝ : SecondCountableTopology β
ht : MeasurableSet t
hg : MonotoneOn g t
t' : Set α := {x | x ∈ t ∧ ¬ContinuousWithinAt g t x}
ht' : t'.Countable
⊢ g '' t = g '' (t \ t' ∪ t')
Module: Mathlib.MeasureTheory.Group.Measure

Goal state before:
pp: case succ
G : Type u_1
inst✝⁸ : MeasurableSpace G
inst✝⁷ : TopologicalSpace G
inst✝⁶ : BorelSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed[inst✝⁷] K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n ↦ (fun T ↦ T ∪ g T • K)^[n] K
n : ℕ
IH : IsCompact (L n)
⊢ IsCompact ((fun T ↦ T ∪ g T • K)^[n + 1] K)

Tactic:
iterate_succ'

Goal state after:
case succ
G : Type u_1
inst✝⁸ : MeasurableSpace G
inst✝⁷ : TopologicalSpace G
inst✝⁶ : BorelSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed[inst✝⁷] K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n ↦ (fun T ↦ T ∪ g T • K)^[n] K
n : ℕ
IH : IsCompact (L n)
⊢ IsCompact (((fun T ↦ T ∪ g T • K) ∘ (fun T ↦ T ∪ g T • K)^[n]) K)
Module: Mathlib.MeasureTheory.Group.LIntegral

Goal state before:
pp: G : Type u_1
inst✝³ : MeasurableSpace G
μ : Measure G
inst✝² : Group G
inst✝¹ : MeasurableMul G
inst✝ : μ.IsMulRightInvariant
f : G → ℝ≥0∞
g : G
⊢ ∫⁻ (x : G), f (x * g) ∂μ = ∫⁻ (x : G), f x ∂μ

Tactic:
by
  convert! (lintegral_map_equiv f <| MeasurableEquiv.mulRight g).symm using 1
  simp [map_mul_right_eq_self μ g]

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

Goal state before:
pp: case succ
G : Type u_1
inst✝⁸ : MeasurableSpace G
inst✝⁷ : TopologicalSpace G
inst✝⁶ : BorelSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed[inst✝⁷] K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n ↦ (fun T ↦ T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
n : ℕ
IH : IsClosed[inst✝⁷] (L n)
⊢ IsClosed[inst✝⁷] ((fun T ↦ T ∪ g T • K)^[n + 1] K)

Tactic:
iterate_succ'

Goal state after:
case succ
G : Type u_1
inst✝⁸ : MeasurableSpace G
inst✝⁷ : TopologicalSpace G
inst✝⁶ : BorelSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed[inst✝⁷] K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n ↦ (fun T ↦ T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
n : ℕ
IH : IsClosed[inst✝⁷] (L n)
⊢ IsClosed[inst✝⁷] (((fun T ↦ T ∪ g T • K) ∘ (fun T ↦ T ∪ g T • K)^[n]) K)
Module: Mathlib.MeasureTheory.Group.Measure

Goal state before:
pp: G : Type u_1
inst✝⁸ : MeasurableSpace G
inst✝⁷ : TopologicalSpace G
inst✝⁶ : BorelSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed[inst✝⁷] K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n ↦ (fun T ↦ T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed[inst✝⁷] (L n)
n : ℕ
IH : μ (L n) = ↑(n + 1) * μ K
⊢ μ ((fun T ↦ T ∪ g T • K)^[n + 1] K) = μ ((fun T ↦ T ∪ g T • K)^[n] K) + μ (g ((fun T ↦ T ∪ g T • K)^[n] K) • K)

Tactic:
iterate_succ'

Goal state after:
G : Type u_1
inst✝⁸ : MeasurableSpace G
inst✝⁷ : TopologicalSpace G
inst✝⁶ : BorelSpace G
inst✝⁵ : Group G
inst✝⁴ : IsTopologicalGroup G
inst✝³ : WeaklyLocallyCompactSpace G
inst✝² : NoncompactSpace G
μ : Measure G
inst✝¹ : μ.IsOpenPosMeasure
inst✝ : μ.IsMulLeftInvariant
K : Set G
K1 : K ∈ 𝓝 1
hK : IsCompact K
Kclosed : IsClosed[inst✝⁷] K
K_pos : 0 < μ K
g : Set G → G
hg : ∀ (L : Set G), IsCompact L → Disjoint L (g L • K)
L : ℕ → Set G := fun n ↦ (fun T ↦ T ∪ g T • K)^[n] K
Lcompact : ∀ (n : ℕ), IsCompact (L n)
Lclosed : ∀ (n : ℕ), IsClosed[inst✝⁷] (L n)
n : ℕ
IH : μ (L n) = ↑(n + 1) * μ K
⊢ μ (((fun T ↦ T ∪ g T • K) ∘ (fun T ↦ T ∪ g T • K)^[n]) K) =
    μ ((fun T ↦ T ∪ g T • K)^[n] K) + μ (g ((fun T ↦ T ∪ g T • K)^[n] K) • K)
Module: Mathlib.MeasureTheory.Measure.WithDensity

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
hf : ∫⁻ (a : α), f a ∂μ ≠ ∞
⊢ (μ.withDensity f) univ < ∞

Tactic:
rwa [withDensity_apply _ MeasurableSet.univ, Measure.restrict_univ, lt_top_iff_ne_top]

Goal state after:
Module: Mathlib.Algebra.QuadraticDiscriminant

Goal state before:
pp: K : Type u_1
inst✝¹ : Field K
inst✝ : NeZero 2
a b c : K
ha : a ≠ 0
h : ∃! x, a * (x * x) + b * x + c = 0
⊢ discrim a b c = 0

Tactic:
simp_rw [quadratic_eq_zero_iff_discrim_eq_sq ha] at h

Goal state after:
K : Type u_1
inst✝¹ : Field K
inst✝ : NeZero 2
a b c : K
ha : a ≠ 0
h : ∃! x, discrim a b c = (2 * a * x + b) ^ 2
⊢ discrim a b c = 0
Module: Mathlib.MeasureTheory.Function.L1Space.HasFiniteIntegral

Goal state before:
pp: α : Type u_1
β : Type u_2
m : MeasurableSpace α
μ : Measure α
inst✝ : NormedAddCommGroup β
F : ℕ → α → β
f : α → β
bound : α → ℝ
h_bound : ∀ (n : ℕ), ∀ᵐ (a : α) ∂μ, ‖F n a‖ ≤ bound a
h_lim : ∀ᵐ (a : α) ∂μ, Tendsto (fun n ↦ F n a) atTop (𝓝 (f a))
F_le_bound✝ : ∀ᵐ (a : α) ∂μ, ∀ (i : ℕ), ENNReal.ofReal ‖F i a‖ ≤ ENNReal.ofReal (bound a)
a : α
tendsto_norm : Tendsto (fun n ↦ ENNReal.ofReal ‖F n a‖) atTop (𝓝 (ENNReal.ofReal ‖f a‖))
F_le_bound : ∀ (i : ℕ), ENNReal.ofReal ‖F i a‖ ≤ ENNReal.ofReal (bound a)
⊢ ENNReal.ofReal ‖f a‖ ≤ ENNReal.ofReal (bound a)

Tactic:
exact le_of_tendsto' tendsto_norm F_le_bound

Goal state after:
Module: Mathlib.Analysis.Real.Sqrt

Goal state before:
pp: x : ℝ
⊢ √1 ≤ √x ↔ √1 ≤ x

Tactic:
sqrt_le_sqrt_iff' zero_lt_one,

Goal state after:
x : ℝ
⊢ 1 ≤ x ↔ √1 ≤ x
Module: Mathlib.MeasureTheory.Measure.WithDensity

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
f : α → ℝ≥0∞
f_meas : Measurable f
g i : α → ℝ≥0∞
i_meas : Measurable i
hi : i ≤ g
⊢ f * i ≤ f * g

Tactic:
grw [hi]

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

Goal state before:
pp: case refine_2
α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
inst✝ : SigmaFinite μ
f : α → ℝ≥0
⊢ ⋃ i, spanningSets μ i ∩ f ⁻¹' Iic ↑i = univ

Tactic:
iUnion_eq_univ_iff

Goal state after:
case refine_2
α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
inst✝ : SigmaFinite μ
f : α → ℝ≥0
⊢ ∀ (x : α), ∃ i, x ∈ spanningSets μ i ∩ f ⁻¹' Iic ↑i
Module: Mathlib.Algebra.Star.Unitary

Goal state before:
pp: G : Type u_2
inst✝¹ : Group G
inst✝ : StarMul G
a b : G
⊢ a * b⁻¹ ∈ unitary G ↔ star a * a = star b * b

Tactic:
rw [(Group.isUnit _).mem_unitary_iff_star_mul_self, star_mul, star_inv, mul_assoc,
    inv_mul_eq_iff_eq_mul, mul_one, ← mul_assoc, mul_inv_eq_iff_eq_mul]

Goal state after: