mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Add

Goal state before:
pp: case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
f✝ : α → ℝ≥0∞
hf✝ : Measurable f✝
f g : α → ℝ≥0∞
a✝¹ : Disjoint (Function.support f) (Function.support g)
hf : Measurable f
a✝ : Measurable g
hf_prop : ∫⁻ (a : α), f a ∂μ.trim hm = ∫⁻ (a : α), f a ∂μ
⊢ ∫⁻ (a : α), g a ∂μ.trim hm = ∫⁻ (a : α), g a ∂μ → ∫⁻ (a : α), (f + g) a ∂μ.trim hm = ∫⁻ (a : α), (f + g) a ∂μ

Tactic:
hg_prop

Goal state after:
case refine_2
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
f✝ : α → ℝ≥0∞
hf✝ : Measurable f✝
f g : α → ℝ≥0∞
a✝¹ : Disjoint (Function.support f) (Function.support g)
hf : Measurable f
a✝ : Measurable g
hf_prop : ∫⁻ (a : α), f a ∂μ.trim hm = ∫⁻ (a : α), f a ∂μ
hg_prop : ∫⁻ (a : α), g a ∂μ.trim hm = ∫⁻ (a : α), g a ∂μ
⊢ ∫⁻ (a : α), (f + g) a ∂μ.trim hm = ∫⁻ (a : α), (f + g) a ∂μ
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: α : Type u_1
E : Type u_5
m m₀ : MeasurableSpace α
μ : Measure α
f g : α → E
inst✝³ : TopologicalSpace E
inst✝² : Preorder E
inst✝¹ : OrderClosedTopology E
inst✝ : PseudoMetrizableSpace E
hm : m ≤ m₀
hf : StronglyMeasurable f
hg : StronglyMeasurable g
hfg : f ≤ᵐ[μ] g
⊢ MeasurableSet {a | ¬f a ≤ g a}

Tactic:
exact (hf.measurableSet_le hg).compl

Goal state after:
Module: Mathlib.Topology.Perfect

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

Tactic:
by_cases h : x ∈ C <;> apply AccPt.mono _ (principal_mono.mpr subset_closure)

Goal state after:
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)

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)
Module: Mathlib.Analysis.Normed.Group.InfiniteSum

Goal state before:
pp: ι : Type u_1
E : Type u_3
inst✝ : SeminormedAddCommGroup E
f : ι → E
g : ι → ℝ≥0
a : ℝ≥0
hg : HasSum g a
h : ∀ (i : ι), ‖f i‖₊ ≤ g i
⊢ ‖∑' (i : ι), f i‖₊ ≤ a

Tactic:
by
  simp only [← NNReal.coe_le_coe, ← NNReal.hasSum_coe, coe_nnnorm] at *
  exact tsum_of_norm_bounded hg h

Goal state after:
Module: Mathlib.Topology.Algebra.MetricSpace.Lipschitz

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
f : α → β
s : Set α
hs : IsCompact s
hf' : ContinuousOn f s
ε : (x : α) → x ∈ s → ℝ
hε : ∀ (x : α) (a : x ∈ s), ε x a > 0
K : (x : α) → x ∈ s → ℝ≥0
hf : ∀ (x : α) (a : x ∈ s), LipschitzOnWith (K x a) f (ball x (ε x a) ∩ s)
x : α
hx : x ∈ s
K' : ℝ
hK' : K' ∈ upperBounds ((fun y ↦ dist (f x) (f y) / dist x y) '' (s \ ball x (ε x hx)))
y : α
hy : y ∈ s.diff (ball x (ε x hx))
⊢ edist (f x) (f y) ≤ ↑(NNReal.mk (max K' 0) ⋯) * edist x y

Tactic:
edist_nndist,

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
f : α → β
s : Set α
hs : IsCompact s
hf' : ContinuousOn f s
ε : (x : α) → x ∈ s → ℝ
hε : ∀ (x : α) (a : x ∈ s), ε x a > 0
K : (x : α) → x ∈ s → ℝ≥0
hf : ∀ (x : α) (a : x ∈ s), LipschitzOnWith (K x a) f (ball x (ε x a) ∩ s)
x : α
hx : x ∈ s
K' : ℝ
hK' : K' ∈ upperBounds ((fun y ↦ dist (f x) (f y) / dist x y) '' (s \ ball x (ε x hx)))
y : α
hy : y ∈ s.diff (ball x (ε x hx))
⊢ ↑(nndist (f x) (f y)) ≤ ↑(NNReal.mk (max K' 0) ⋯) * ↑(nndist x y)
Module: Mathlib.Topology.MetricSpace.PiNat

Goal state before:
pp: E : ℕ → Type u_1
x y : (n : ℕ) → E n
n : ℕ
⊢ y ∈ cylinder x n ↔ cylinder y n = cylinder x n

Tactic:
constructor
  · intro hy
    apply Subset.antisymm
    · intro z hz i hi
      rw [← hy i hi]
      exact hz i hi
    · intro z hz i hi
      rw [hy i hi]
      exact hz i hi
  · intro h
    rw [← h]
    exact self_mem_cylinder _ _

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

Goal state before:
pp: X : ℕ → Type u
inst✝ : (n : ℕ) → MetricSpace (X n)
f : (n : ℕ) → X n → X (n + 1)
I : ∀ (n : ℕ), Isometry (f n)
x y : (n : ℕ) × X n
hx : x.fst ≤ 0
hy : y.fst ≤ 0
⊢ inductiveLimitDist f x y = dist (leRecOn hx (fun {k} ↦ f k) x.snd) (leRecOn hy (fun {k} ↦ f k) y.snd)

Tactic:
obtain ⟨i, x⟩ := x

Goal state after:
X : ℕ → Type u
inst✝ : (n : ℕ) → MetricSpace (X n)
f : (n : ℕ) → X n → X (n + 1)
I : ∀ (n : ℕ), Isometry (f n)
y : (n : ℕ) × X n
hy : y.fst ≤ 0
i : ℕ
x : X i
hx : ⟨i, x⟩.fst ≤ 0
⊢ inductiveLimitDist f ⟨i, x⟩ y = dist (leRecOn hx (fun {k} ↦ f k) ⟨i, x⟩.snd) (leRecOn hy (fun {k} ↦ f k) y.snd)
Module: Mathlib.Topology.MetricSpace.CantorScheme

Goal state before:
pp: β : Type u_1
α : Type u_2
A : List β → Set α
inst✝¹ : PseudoMetricSpace α
inst✝ : CompleteSpace α
hdiam : VanishingDiam A
hanti : ClosureAntitone A
hnonempty : ∀ (l : List β), (A l).Nonempty
x : ℕ → β
u : ℕ → α
hu : ∀ (n : ℕ), u n ∈ A (res x n)
umem : ∀ (n m : ℕ), n ≤ m → u m ∈ A (res x n)
ε : ℝ
ε_pos : ε > 0
⊢ ∃ N, ∀ m ≥ N, ∀ n ≥ N, dist (u m) (u n) < ε

Tactic:
obtain ⟨n, hn⟩ := hdiam.dist_lt _ ε_pos x

Goal state after:
β : Type u_1
α : Type u_2
A : List β → Set α
inst✝¹ : PseudoMetricSpace α
inst✝ : CompleteSpace α
hdiam : VanishingDiam A
hanti : ClosureAntitone A
hnonempty : ∀ (l : List β), (A l).Nonempty
x : ℕ → β
u : ℕ → α
hu : ∀ (n : ℕ), u n ∈ A (res x n)
umem : ∀ (n m : ℕ), n ≤ m → u m ∈ A (res x n)
ε : ℝ
ε_pos : ε > 0
n : ℕ
hn : ∀ y ∈ A (res x n), ∀ z ∈ A (res x n), dist y z < ε
⊢ ∃ N, ∀ m ≥ N, ∀ n ≥ N, dist (u m) (u n) < ε
Module: Mathlib.Topology.MetricSpace.Gluing

Goal state before:
pp: case neg
X : ℕ → Type u
inst✝ : (n : ℕ) → MetricSpace (X n)
f : (n : ℕ) → X n → X (n + 1)
I : ∀ (n : ℕ), Isometry (f n)
x y : (n : ℕ) × X n
m : ℕ
hx : x.fst ≤ m + 1
hy : y.fst ≤ m + 1
h : ¬max x.fst y.fst = m + 1
⊢ inductiveLimitDist f x y = dist (leRecOn hx (fun {k} ↦ f k) x.snd) (leRecOn hy (fun {k} ↦ f k) y.snd)

Tactic:
have : max x.1 y.1 ≤ succ m := by simp [hx, hy]
      have : max x.1 y.1 ≤ m := by simpa [h] using of_le_succ this
      have xm : x.1 ≤ m := le_trans (le_max_left _ _) this
      have ym : y.1 ≤ m := le_trans (le_max_right _ _) this
      rw [leRecOn_succ xm, leRecOn_succ ym, (I m).dist_eq]
      exact inductiveLimitDist_eq_dist I x y m xm ym

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✝² : MeasurableSpace α
inst✝¹ : MeasurableSpace β
inst✝ : MeasurableSpace γ
μa : Measure α
μb : Measure β
μc : Measure γ
g : α → β
e : β ≃ᵐ γ
h : MeasurePreserving (⇑e) μb μc
hg : MeasurePreserving (⇑e ∘ g) μa μc
⊢ g = ⇑e.symm ∘ ⇑e ∘ g

Tactic:
simp [← Function.comp_assoc e.symm e g]

Goal state after:
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
y : (n : ℕ) → E n
hy : y ∈ s
⊢ f y ∈ s

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
y : (n : ℕ) → E n
hy : y ∉ s
⊢ f y ∈ s

Tactic:
· rwa [fs y hy]

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
y : (n : ℕ) → E n
hy : y ∉ s
⊢ f y ∈ s
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Map

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : MeasurableSpace α
inst✝ : MeasurableSpace β
μ : Measure α
g : α → β
hg : MeasurableEmbedding g
f : β → ℝ≥0∞
f₀ : SimpleFunc β ℝ≥0∞
hf₀ : ⇑f₀ ≤ fun a ↦ f a
this : ⇑(f₀.comp g ⋯) ≤ f ∘ g
⊢ (f₀.comp g ⋯).lintegral μ ≤ ⨆ (_ : ⇑(f₀.comp g ⋯) ≤ fun a ↦ f (g a)), (f₀.comp g ⋯).lintegral μ

Tactic:
exact le_iSup (α := ℝ≥0∞) _ this

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Typeclasses.Probability

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
inst✝ : IsProbabilityMeasure μ
maybe_empty : IsEmpty α
⊢ μ univ = 0

Tactic:
rw [Set.univ_eq_empty_iff.mpr maybe_empty, measure_empty]

Goal state after:
Module: Mathlib.MeasureTheory.Measure.Typeclasses.Probability

Goal state before:
pp: α : Type u_1
β : Type u_2
m0 : MeasurableSpace α
inst✝¹ : MeasurableSpace β
μ : Measure α
s : Set α
inst✝ : IsProbabilityMeasure μ
p : α → Prop
f✝ : β → α
f : β ≃ᵐ α
⊢ IsProbabilityMeasure (Measure.map (⇑f.symm) μ)

Tactic:
exact isProbabilityMeasure_map f.symm.measurable.aemeasurable

Goal state after:
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
⊢ μ sᶜᶜ = 0 ↔ μ s = 0

Tactic:
compl_compl

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 = 0 ↔ μ s = 0
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 (⋃ i, (t i)ᶜ) ≤ 2 * ↑ε

Tactic:
(by simp [ENNReal.tsum_mul_left, mul_comm] :
      2 * (ε : ℝ≥0∞) = ∑' (n : ℕ), ε * (1 / 2 : ℝ≥0∞) ^ n)

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) ≤ ∑' (n : ℕ), ↑ε * (1 / 2) ^ n
Module: Mathlib.MeasureTheory.Measure.MutuallySingular

Goal state before:
pp: case refine_1
α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
h : μ ⟂ₘ ν
s : Set α
a✝ : s ∈ ⊥
⊢ μ (sᶜ ∩ h.nullSetᶜᶜ) = 0

Tactic:
compl_compl

Goal state after:
case refine_1
α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
h : μ ⟂ₘ ν
s : Set α
a✝ : s ∈ ⊥
⊢ μ (sᶜ ∩ h.nullSet) = 0
Module: Mathlib.MeasureTheory.Measure.MutuallySingular

Goal state before:
pp: case refine_3
α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
h : μ ⟂ₘ ν
s : Set α
a✝ : s ∈ ⊥
⊢ s = sᶜᶜ

Tactic:
compl_compl

Goal state after:
case refine_3
α : Type u_1
m0 : MeasurableSpace α
μ ν : Measure α
h : μ ⟂ₘ ν
s : Set α
a✝ : s ∈ ⊥
⊢ s = s
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: X : Type u_3
Y : Type u_4
inst✝⁵ : MeasurableSpace X
inst✝⁴ : StandardBorelSpace X
inst✝³ : TopologicalSpace Y
inst✝² : MeasurableSpace Y
inst✝¹ : OpensMeasurableSpace Y
f : X → Y
inst✝ : SecondCountableTopology ↑(range f)
s : Set X
hs : MeasurableSet s
hf : Measurable f
⊢ AnalyticSet (f '' s)

Tactic:
let := upgradeStandardBorel X

Goal state after:
X : Type u_3
Y : Type u_4
inst✝⁵ : MeasurableSpace X
inst✝⁴ : StandardBorelSpace X
inst✝³ : TopologicalSpace Y
inst✝² : MeasurableSpace Y
inst✝¹ : OpensMeasurableSpace Y
f : X → Y
inst✝ : SecondCountableTopology ↑(range f)
s : Set X
hs : MeasurableSet s
hf : Measurable f
this : UpgradedStandardBorel X := upgradeStandardBorel X
⊢ AnalyticSet (f '' s)
Module: Mathlib.Topology.MetricSpace.PiNat

Goal state before:
pp: case inr
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
hne : x ≠ y
hne' : ↑x ≠ ↑y
dist' : dist x y = dist ↑x ↑y
n : ℕ := firstDiff ↑x ↑y - 1
diff_pos : 0 < firstDiff ↑x ↑y
hn : firstDiff ↑x ↑y = n + 1
⊢ dist (g x) (g y) ≤ 4 * dist x y

Tactic:
dist',

Goal state after:
case inr
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
hne : x ≠ y
hne' : ↑x ≠ ↑y
dist' : dist x y = dist ↑x ↑y
n : ℕ := firstDiff ↑x ↑y - 1
diff_pos : 0 < firstDiff ↑x ↑y
hn : firstDiff ↑x ↑y = n + 1
⊢ dist (g x) (g y) ≤ 4 * dist ↑x ↑y
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: α : Type u_1
inst✝³ : TopologicalSpace α
inst✝² : T2Space α
inst✝¹ : MeasurableSpace α
inst✝ : OpensMeasurableSpace α
f g : (ℕ → ℕ) → α
hf : Continuous[_, inst✝³] f
hg : Continuous[_, inst✝³] g
h : Disjoint (range f) (range g)
hfg : ¬MeasurablySeparable (range f) (range g)
I :
  ∀ (n : ℕ) (x y : ℕ → ℕ),
    ¬MeasurablySeparable (f '' cylinder x n) (g '' cylinder y n) →
      ∃ x' y',
        x' ∈ cylinder x n ∧
          y' ∈ cylinder y n ∧ ¬MeasurablySeparable (f '' cylinder x' (n + 1)) (g '' cylinder y' (n + 1))
A : Type := { p // ¬MeasurablySeparable (f '' cylinder p.2.1 p.1) (g '' cylinder p.2.2 p.1) }
F : A → A
hFn : ∀ (p : A), (↑(F p)).1 = (↑p).1 + 1
hFx : ∀ (p : A), (↑(F p)).2.1 ∈ cylinder (↑p).2.1 (↑p).1
hFy : ∀ (p : A), (↑(F p)).2.2 ∈ cylinder (↑p).2.2 (↑p).1
p0 : A := ⟨(0, fun x ↦ 0, fun x ↦ 0), ⋯⟩
p : ℕ → A := fun n ↦ F^[n] p0
n : ℕ
⊢ p (n + 1) = F (p n)

Tactic:
by simp only [p, iterate_succ', Function.comp]

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

Goal state before:
pp: case pos
α : Type u_1
m : MeasurableSpace α
μ : Measure α
inst✝ : SigmaFinite μ
f₁ f₂ : α →ₛ ℝ≥0
a✝ : Disjoint (Function.support ⇑f₁) (Function.support ⇑f₂)
h₁ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₁ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₁ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
h₂ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₂ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₂ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
L : ℝ≥0∞
hf₁ : ∫⁻ (x : α), ↑(f₁ x) ∂μ = 0
hL : L < ∫⁻ (x : α), ↑(f₂ x) ∂μ
g : α →ₛ ℝ≥0
g_le : ∀ (x : α), g x ≤ f₂ x
g_top : ∫⁻ (x : α), ↑(g x) ∂μ < ∞
gL : L < ∫⁻ (x : α), ↑(g x) ∂μ
⊢ ∃ g, (∀ (x : α), g x ≤ (f₁ + f₂) x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ

Tactic:
refine ⟨g, fun x => (g_le x).trans ?_, g_top, gL⟩

Goal state after:
case pos
α : Type u_1
m : MeasurableSpace α
μ : Measure α
inst✝ : SigmaFinite μ
f₁ f₂ : α →ₛ ℝ≥0
a✝ : Disjoint (Function.support ⇑f₁) (Function.support ⇑f₂)
h₁ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₁ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₁ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
h₂ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₂ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₂ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
L : ℝ≥0∞
hf₁ : ∫⁻ (x : α), ↑(f₁ x) ∂μ = 0
hL : L < ∫⁻ (x : α), ↑(f₂ x) ∂μ
g : α →ₛ ℝ≥0
g_le : ∀ (x : α), g x ≤ f₂ x
g_top : ∫⁻ (x : α), ↑(g x) ∂μ < ∞
gL : L < ∫⁻ (x : α), ↑(g x) ∂μ
x : α
⊢ f₂ x ≤ (f₁ + f₂) x
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
C : ℝ≥0 := doublingConstant μ
this : ∀ (n : ℕ), ∀ᶠ (ε : ℝ) in 𝓝[>] 0, ∀ (x : α), μ (closedBall x (2 ^ n * ε)) ≤ ↑C ^ n * μ (closedBall x ε)
n : ℕ
hn : K < 2 ^ n
ε : ℝ
hε₀ : 0 < ε
hε : ∀ (x : α), μ (closedBall x (2 ^ n * ε)) ≤ ↑C ^ n * μ (closedBall x ε)
x : α
t : ℝ
ht : t ≤ K
⊢ μ (closedBall x (2 ^ n * ε)) ≤ ↑C ^ n * μ (closedBall x ε)

Tactic:
exact hε x

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

Goal state before:
pp: case pos
α : Type u_1
m : MeasurableSpace α
μ : Measure α
inst✝ : SigmaFinite μ
f₁ f₂ : α →ₛ ℝ≥0
a✝ : Disjoint (Function.support ⇑f₁) (Function.support ⇑f₂)
h₁ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₁ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₁ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
h₂ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₂ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₂ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
L : ℝ≥0∞
hf₁ : ¬∫⁻ (x : α), ↑(f₁ x) ∂μ = 0
hf₂ : ∫⁻ (x : α), ↑(f₂ x) ∂μ = 0
hL : L < ∫⁻ (x : α), ↑(f₁ x) ∂μ
g : α →ₛ ℝ≥0
g_le : ∀ (x : α), g x ≤ f₁ x
g_top : ∫⁻ (x : α), ↑(g x) ∂μ < ∞
gL : L < ∫⁻ (x : α), ↑(g x) ∂μ
⊢ ∃ g, (∀ (x : α), g x ≤ (f₁ + f₂) x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ

Tactic:
refine ⟨g, fun x => (g_le x).trans ?_, g_top, gL⟩

Goal state after:
case pos
α : Type u_1
m : MeasurableSpace α
μ : Measure α
inst✝ : SigmaFinite μ
f₁ f₂ : α →ₛ ℝ≥0
a✝ : Disjoint (Function.support ⇑f₁) (Function.support ⇑f₂)
h₁ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₁ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₁ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
h₂ :
  ∀ {L : ℝ≥0∞},
    L < ∫⁻ (x : α), ↑(f₂ x) ∂μ → ∃ g, (∀ (x : α), g x ≤ f₂ x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
L : ℝ≥0∞
hf₁ : ¬∫⁻ (x : α), ↑(f₁ x) ∂μ = 0
hf₂ : ∫⁻ (x : α), ↑(f₂ x) ∂μ = 0
hL : L < ∫⁻ (x : α), ↑(f₁ x) ∂μ
g : α →ₛ ℝ≥0
g_le : ∀ (x : α), g x ≤ f₁ x
g_top : ∫⁻ (x : α), ↑(g x) ∂μ < ∞
gL : L < ∫⁻ (x : α), ↑(g x) ∂μ
x : α
⊢ f₁ x ≤ (f₁ + f₂) x
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: case refine_2
α : Type u_1
inst✝³ : TopologicalSpace α
inst✝² : T2Space α
inst✝¹ : MeasurableSpace α
inst✝ : OpensMeasurableSpace α
f g : (ℕ → ℕ) → α
hf : Continuous[_, inst✝³] f
hg : Continuous[_, inst✝³] g
h : Disjoint (range f) (range g)
hfg : ¬MeasurablySeparable (range f) (range g)
I :
  ∀ (n : ℕ) (x y : ℕ → ℕ),
    ¬MeasurablySeparable (f '' cylinder x n) (g '' cylinder y n) →
      ∃ x' y',
        x' ∈ cylinder x n ∧
          y' ∈ cylinder y n ∧ ¬MeasurablySeparable (f '' cylinder x' (n + 1)) (g '' cylinder y' (n + 1))
A : Type := { p // ¬MeasurablySeparable (f '' cylinder p.2.1 p.1) (g '' cylinder p.2.2 p.1) }
F : A → A
hFn : ∀ (p : A), (↑(F p)).1 = (↑p).1 + 1
hFx : ∀ (p : A), (↑(F p)).2.1 ∈ cylinder (↑p).2.1 (↑p).1
hFy : ∀ (p : A), (↑(F p)).2.2 ∈ cylinder (↑p).2.2 (↑p).1
p0 : A := ⟨(0, fun x ↦ 0, fun x ↦ 0), ⋯⟩
p : ℕ → A := fun n ↦ F^[n] p0
prec : ∀ (n : ℕ), p (n + 1) = F (p n)
pn_fst : ∀ (n : ℕ), (↑(p n)).1 = n
Ix : ∀ (m n : ℕ), m + 1 ≤ n → (↑(p n)).2.1 m = (↑(p (m + 1))).2.1 m
Iy : ∀ (m n : ℕ), m + 1 ≤ n → (↑(p n)).2.2 m = (↑(p (m + 1))).2.2 m
x : ℕ → ℕ := fun n ↦ (↑(p (n + 1))).2.1 n
hx : x = fun n ↦ (↑(p (n + 1))).2.1 n
y : ℕ → ℕ := fun n ↦ (↑(p (n + 1))).2.2 n
hy : y = fun n ↦ (↑(p (n + 1))).2.2 n
M : ∀ (n : ℕ), ¬MeasurablySeparable (f '' cylinder x n) (g '' cylinder y n)
u v : Set α
u_open : IsOpen[inst✝³] u
v_open : IsOpen[inst✝³] v
xu : f x ∈ u
yv : g y ∈ v
huv : Disjoint u v
this : MetricSpace (ℕ → ℕ) := metricSpaceNatNat
εx : ℝ
εxpos : εx > 0
hεx : ball x εx ⊆ f ⁻¹' u
εy : ℝ
εypos : εy > 0
hεy : ball y εy ⊆ g ⁻¹' v
n : ℕ
hn : (1 / 2) ^ n < min εx εy
⊢ cylinder y n ⊆ g ⁻¹' v

Tactic:
apply Subset.trans _ hεy

Goal state after:
α : Type u_1
inst✝³ : TopologicalSpace α
inst✝² : T2Space α
inst✝¹ : MeasurableSpace α
inst✝ : OpensMeasurableSpace α
f g : (ℕ → ℕ) → α
hf : Continuous[_, inst✝³] f
hg : Continuous[_, inst✝³] g
h : Disjoint (range f) (range g)
hfg : ¬MeasurablySeparable (range f) (range g)
I :
  ∀ (n : ℕ) (x y : ℕ → ℕ),
    ¬MeasurablySeparable (f '' cylinder x n) (g '' cylinder y n) →
      ∃ x' y',
        x' ∈ cylinder x n ∧
          y' ∈ cylinder y n ∧ ¬MeasurablySeparable (f '' cylinder x' (n + 1)) (g '' cylinder y' (n + 1))
A : Type := ⋯
F : A → A
hFn : ∀ (p : A), (↑(F p)).1 = (↑p).1 + 1
hFx : ∀ (p : A), (↑(F p)).2.1 ∈ cylinder (↑p).2.1 (↑p).1
hFy : ∀ (p : A), (↑(F p)).2.2 ∈ cylinder (↑p).2.2 (↑p).1
p0 : A := ⋯
p : ℕ → A := ⋯
prec : ∀ (n : ℕ), p (n + 1) = F (p n)
pn_fst : ∀ (n : ℕ), (↑(p n)).1 = n
Ix : ∀ (m n : ℕ), m + 1 ≤ n → (↑(p n)).2.1 m = (↑(p (m + 1))).2.1 m
Iy : ∀ (m n : ℕ), m + 1 ≤ n → (↑(p n)).2.2 m = (↑(p (m + 1))).2.2 m
x : ℕ → ℕ := ⋯
hx : x = fun n ↦ (↑(p (n + 1))).2.1 n
y : ℕ → ℕ := ⋯
hy : y = fun n ↦ (↑(p (n + 1))).2.2 n
M : ∀ (n : ℕ), ¬MeasurablySeparable (f '' cylinder x n) (g '' cylinder y n)
u v : Set α
u_open : IsOpen[inst✝³] u
v_open : IsOpen[inst✝³] v
xu : f x ∈ u
yv : g y ∈ v
huv : Disjoint u v
this : MetricSpace (ℕ → ℕ) := metricSpaceNatNat
εx : ℝ
εxpos : εx > 0
hεx : ball x εx ⊆ f ⁻¹' u
εy : ℝ
εypos : εy > 0
hεy : ball y εy ⊆ g ⁻¹' v
n : ℕ
hn : (1 / 2) ^ n < min εx εy
⊢ cylinder y n ⊆ ball y εy
Module: Mathlib.GroupTheory.Complement

Goal state before:
pp: G : Type u_1
inst✝ : Group G
S : Set G
g : G
⊢ IsComplement {g} S ↔ S = univ

Tactic:
refine
    ⟨fun h => top_le_iff.mp fun x _ => ?_, fun h => (congr_arg _ h).mpr isComplement_singleton_univ⟩

Goal state after:
G : Type u_1
inst✝ : Group G
S : Set G
g : G
h : IsComplement {g} S
x : G
x✝ : x ∈ ⊤
⊢ x ∈ S
Module: Mathlib.GroupTheory.Complement

Goal state before:
pp: G : Type u_1
inst✝ : Group G
H : Subgroup G
f : G ⧸ H → G
hf : ∀ (q : G ⧸ H), ↑(f q) = q
⊢ IsComplement (range f) ↑H

Tactic:
by
  rw [isComplement_subgroup_right_iff_bijective]
  refine ⟨?_, fun q ↦ ⟨⟨f q, q, rfl⟩, hf q⟩⟩
  rintro ⟨-, q₁, rfl⟩ ⟨-, q₂, rfl⟩ h
  exact Subtype.ext <| congr_arg f <| ((hf q₁).symm.trans h).trans (hf q₂)

Goal state after:
Module: Mathlib.GroupTheory.Complement

Goal state before:
pp: case mpr
G : Type u_1
inst✝ : Group G
S T : Set G
hST : IsComplement S T
g : G
h1 : 1 ∈ S
h : g ∈ T
⊢ ↑(hST.equiv g).2 = g

Tactic:
rw [hST.equiv_snd_eq_self_of_mem_of_one_mem h1 h]

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

Goal state before:
pp: α : Type u_1
inst✝³ : MeasurableSpace α
μ : Measure α
inst✝² : TopologicalSpace α
inst✝¹ : R1Space α
inst✝ : μ.OuterRegular
k : Set α
hk : IsCompact k
⊢ μ (closure[inst✝²] k) = μ k

Tactic:
apply le_antisymm ?_ (measure_mono subset_closure)
  simp only [measure_eq_iInf_isOpen k, le_iInf_iff]
  intro u ku u_open
  exact measure_mono (hk.closure_subset_of_isOpen u_open ku)

Goal state after:
Module: Mathlib.Topology.ContinuousMap.CocompactMap

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
inst✝ : TopologicalSpace β
f : CocompactMap α β
s : Set β
hs : IsCompact s
h's : IsClosed s
t : Set α
ht : IsCompact t
hts : (⇑f ⁻¹' s)ᶜᶜ ⊆ t
⊢ IsCompact (⇑f ⁻¹' s)

Tactic:
exact
    ht.of_isClosed_subset (h's.preimage <| map_continuous f) (by simpa using hts)

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

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝⁴ : MeasurableSpace α
inst✝³ : MeasurableSpace β
μ : Measure α
ν : Measure β
inst✝² : SFinite ν
inst✝¹ : SFinite μ
μ' : Measure α
inst✝ : SFinite μ'
i : ℕ × ℕ
s : Set α
t : Set β
x✝¹ : MeasurableSet s
x✝ : MeasurableSet t
⊢ (sfiniteSeq μ i.1) s * (sfiniteSeq ν i.2) t + (sfiniteSeq μ' i.1) s * (sfiniteSeq ν i.2) t =
    ((sfiniteSeq μ i.1) s + (sfiniteSeq μ' i.1) s) * (sfiniteSeq ν i.2) t

Tactic:
right_distrib

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

Goal state before:
pp: G : Type u_1
H✝ : Type u_2
inst✝⁹ : MeasurableSpace G
inst✝⁸ : MeasurableSpace H✝
inst✝⁷ : Mul G
μ : Measure G
inst✝⁶ : MeasurableMul G
inst✝⁵ : μ.IsMulLeftInvariant
inst✝⁴ : SFinite μ
H : Type u_3
inst✝³ : Mul H
mH : MeasurableSpace H
ν : Measure H
inst✝² : MeasurableMul H
inst✝¹ : ν.IsMulLeftInvariant
inst✝ : SFinite ν
⊢ ∀ (g : G × H), map (fun x ↦ g * x) (μ.prod ν) = μ.prod ν

Tactic:
rintro ⟨g, h⟩

Goal state after:
G : Type u_1
H✝ : Type u_2
inst✝⁹ : MeasurableSpace G
inst✝⁸ : MeasurableSpace H✝
inst✝⁷ : Mul G
μ : Measure G
inst✝⁶ : MeasurableMul G
inst✝⁵ : μ.IsMulLeftInvariant
inst✝⁴ : SFinite μ
H : Type u_3
inst✝³ : Mul H
mH : MeasurableSpace H
ν : Measure H
inst✝² : MeasurableMul H
inst✝¹ : ν.IsMulLeftInvariant
inst✝ : SFinite ν
g : G
h : H
⊢ map (fun x ↦ (g, h) * x) (μ.prod ν) = μ.prod ν