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

Goal state before:
pp: α : Type u_1
m₀ : MeasurableSpace α
μ : Measure α
inst✝² : TopologicalSpace α
inst✝¹ : PseudoMetrizableSpace α
inst✝ : OpensMeasurableSpace α
s : Set α
h1 : IsSeparable s
h2 : μ sᶜ = 0
a✝ : Nontrivial α
a : α
this : SecondCountableTopology ↑(closure[inst✝²] s)
⊢ StronglyMeasurable Subtype.val

Tactic:
exact continuous_subtype_val.stronglyMeasurable

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

Goal state before:
pp: α : Type u_1
β : Type u_2
x✝ : MeasurableSpace α
f : α → β
inst✝ : TopologicalSpace β
hf : ∀ (x y : α), f x = f y
⊢ StronglyMeasurable f

Tactic:
by
  nontriviality α
  inhabit α
  convert! stronglyMeasurable_const (β := β) using 1
  exact funext fun x => hf x default

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

Goal state before:
pp: case cons
α : Type u_1
m₀ : MeasurableSpace α
μ : Measure α
M : Type u_5
inst✝² : Monoid M
inst✝¹ : TopologicalSpace M
inst✝ : ContinuousMul M
f : α → M
l : List (α → M)
ihl : (∀ f ∈ l, AEStronglyMeasurable f μ) → AEStronglyMeasurable l.prod μ
hl : ∀ f_1 ∈ f :: l, AEStronglyMeasurable f_1 μ
⊢ AEStronglyMeasurable (f :: l).prod μ

Tactic:
rw [List.forall_mem_cons] at hl
    rw [List.prod_cons]
    exact hl.1.mul (ihl hl.2)

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

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝³ : TopologicalSpace β
m₀ : MeasurableSpace α
μ : Measure α
inst✝² : Preorder β
inst✝¹ : OrderClosedTopology β
inst✝ : PseudoMetrizableSpace β
f g : α → β
hf : AEStronglyMeasurable f μ
hg : AEStronglyMeasurable g μ
⊢ NullMeasurableSet {a | f a < g a} μ

Tactic:
apply
    (hf.stronglyMeasurable_mk.measurableSet_lt hg.stronglyMeasurable_mk).nullMeasurableSet.congr
  filter_upwards [hf.ae_eq_mk, hg.ae_eq_mk] with x hfx hgx
  change (hf.mk f x < hg.mk g x) = (f x < g x)
  simp only [hfx, hgx]

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

Goal state before:
pp: α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hle : f ≤ᵐ[μ] g
hg : AEMeasurable g μ
ε : ℝ≥0∞
φ : α → ℝ≥0∞
hφm : Measurable φ
hφ_le : φ ≤ f
hφ_eq : ∫⁻ (a : α), f a ∂μ = ∫⁻ (a : α), φ a ∂μ
⊢ ∫⁻ (x : α), φ x ∂μ + ε * μ {x | φ x + ε ≤ g x} = ∫⁻ (a : α), φ a ∂μ + ∫⁻ (a : α) in {x | φ x + ε ≤ g x}, ε ∂μ

pp: case hs
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hle : f ≤ᵐ[μ] g
hg : AEMeasurable g μ
ε : ℝ≥0∞
φ : α → ℝ≥0∞
hφm : Measurable φ
hφ_le : φ ≤ f
hφ_eq : ∫⁻ (a : α), f a ∂μ = ∫⁻ (a : α), φ a ∂μ
⊢ NullMeasurableSet {x | φ x + ε ≤ g x} μ

Tactic:
setLIntegral_const

Goal state after:
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hle : f ≤ᵐ[μ] g
hg : AEMeasurable g μ
ε : ℝ≥0∞
φ : α → ℝ≥0∞
hφm : Measurable φ
hφ_le : φ ≤ f
hφ_eq : ∫⁻ (a : α), f a ∂μ = ∫⁻ (a : α), φ a ∂μ
⊢ ∫⁻ (x : α), φ x ∂μ + ε * μ {x | φ x + ε ≤ g x} = ∫⁻ (a : α), φ a ∂μ + ε * μ {x | φ x + ε ≤ g x}

case hs
α : Type u_1
mα : MeasurableSpace α
μ : Measure α
f g : α → ℝ≥0∞
hle : f ≤ᵐ[μ] g
hg : AEMeasurable g μ
ε : ℝ≥0∞
φ : α → ℝ≥0∞
hφm : Measurable φ
hφ_le : φ ≤ f
hφ_eq : ∫⁻ (a : α), f a ∂μ = ∫⁻ (a : α), φ a ∂μ
⊢ NullMeasurableSet {x | φ x + ε ≤ g x} μ
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
R : Type u_4
inst✝¹ : SMul R ℝ≥0∞
inst✝ : IsScalarTower R ℝ≥0∞ ℝ≥0∞
c : R
f : α → ℝ≥0∞
s : Set α
⊢ ∫⁻ (a : α) in s, f a ∂c • μ = c • ∫⁻ (a : α) in s, f a ∂μ

Tactic:
Measure.restrict_smul,

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
R : Type u_4
inst✝¹ : SMul R ℝ≥0∞
inst✝ : IsScalarTower R ℝ≥0∞ ℝ≥0∞
c : R
f : α → ℝ≥0∞
s : Set α
⊢ ∫⁻ (a : α), f a ∂c • μ.restrict s = c • ∫⁻ (a : α) in s, f a ∂μ
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Basic

Goal state before:
pp: α : Type u_1
m : MeasurableSpace α
μ : Measure α
s : Set α
hs : NullMeasurableSet s μ
c : ℝ≥0∞
⊢ ∫⁻ (a : α) in s, c ∂μ = c * μ s

Tactic:
setLIntegral_const

Goal state after:
α : Type u_1
m : MeasurableSpace α
μ : Measure α
s : Set α
hs : NullMeasurableSet s μ
c : ℝ≥0∞
⊢ c * μ s = c * μ s
Module: Mathlib.MeasureTheory.Function.StronglyMeasurable.Basic

Goal state before:
pp: case cons
α : Type u_1
M : Type u_5
inst✝² : Monoid M
inst✝¹ : TopologicalSpace M
inst✝ : ContinuousMul M
m : MeasurableSpace α
f : α → M
l : List (α → M)
ihl : (∀ f ∈ l, StronglyMeasurable f) → StronglyMeasurable l.prod
hl : ∀ f_1 ∈ f :: l, StronglyMeasurable f_1
⊢ StronglyMeasurable (f :: l).prod

Tactic:
rw [List.forall_mem_cons] at hl
    rw [List.prod_cons]
    exact hl.1.mul (ihl hl.2)

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 : ∀ (i : β), AEMeasurable (f i) μ
⊢ ⨆ b, ∫⁻ (a : α), ∑ i ∈ b, f i a ∂μ = ⨆ s, ∑ i ∈ s, ∫⁻ (a : α), f i a ∂μ

Tactic:
simp [lintegral_finsetSum' _ fun i _ => hf i]

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

Goal state before:
pp: case refine_1
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
f : α → ℝ≥0∞
hf : Measurable f
c : ℝ≥0∞
s : Set α
hs : MeasurableSet s
⊢ c * (μ.trim hm) s = ∫⁻ (a : α) in s, c ∂μ

Tactic:
setLIntegral_const

Goal state after:
case refine_1
α : Type u_1
m m0 : MeasurableSpace α
μ : Measure α
hm : m ≤ m0
f : α → ℝ≥0∞
hf : Measurable f
c : ℝ≥0∞
s : Set α
hs : MeasurableSet s
⊢ c * (μ.trim hm) s = c * μ s
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 : 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)
⊢ ν (μ.sigmaFiniteSetWRT' ν ∪ s) ≤ ν (μ.sigmaFiniteSetWRT' ν)

Tactic:
conv_rhs => rw [measure_sigmaFiniteSetWRT']

Goal state after:
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)
⊢ ν (μ.sigmaFiniteSetWRT' ν ∪ s) ≤ ⨆ s, ⨆ (_ : MeasurableSet s), ⨆ (_ : SigmaFinite (μ.restrict s)), ν s
Module: Mathlib.Topology.Algebra.MetricSpace.Lipschitz

Goal state before:
pp: case refine_1
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
f : α → β
hf : LipschitzWith K f
u : ℕ → α
hu : CauchySeq u
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ ∀ (n : ℕ), 0 ≤ (fun n ↦ ↑K * b n) n

pp: case refine_2
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
f : α → β
hf : LipschitzWith K f
u : ℕ → α
hu : CauchySeq u
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist ((f ∘ u) n) ((f ∘ u) m) ≤ (fun n ↦ ↑K * b n) N

pp: case refine_3
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
f : α → β
hf : LipschitzWith K f
u : ℕ → α
hu : CauchySeq u
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ Tendsto (fun n ↦ ↑K * b n) atTop (nhds 0)

Tactic:
· exact fun n ↦ mul_nonneg (by positivity) (b_nonneg n)

Goal state after:
case refine_2
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
f : α → β
hf : LipschitzWith K f
u : ℕ → α
hu : CauchySeq u
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist ((f ∘ u) n) ((f ∘ u) m) ≤ (fun n ↦ ↑K * b n) N

case refine_3
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
f : α → β
hf : LipschitzWith K f
u : ℕ → α
hu : CauchySeq u
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ Tendsto (fun n ↦ ↑K * b n) atTop (nhds 0)
Module: Mathlib.Topology.Algebra.MetricSpace.Lipschitz

Goal state before:
pp: case refine_1
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
s : Set α
f : α → β
hf : LipschitzOnWith K f s
u : ℕ → α
hu : CauchySeq u
h'u : range u ⊆ s
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ ∀ (n : ℕ), 0 ≤ (fun n ↦ ↑K * b n) n

pp: case refine_2
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
s : Set α
f : α → β
hf : LipschitzOnWith K f s
u : ℕ → α
hu : CauchySeq u
h'u : range u ⊆ s
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist ((f ∘ u) n) ((f ∘ u) m) ≤ (fun n ↦ ↑K * b n) N

pp: case refine_3
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
s : Set α
f : α → β
hf : LipschitzOnWith K f s
u : ℕ → α
hu : CauchySeq u
h'u : range u ⊆ s
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ Tendsto (fun n ↦ ↑K * b n) atTop (nhds 0)

Tactic:
· exact fun n ↦ mul_nonneg (by positivity) (b_nonneg n)

Goal state after:
case refine_2
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
s : Set α
f : α → β
hf : LipschitzOnWith K f s
u : ℕ → α
hu : CauchySeq u
h'u : range u ⊆ s
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist ((f ∘ u) n) ((f ∘ u) m) ≤ (fun n ↦ ↑K * b n) N

case refine_3
α : Type u_1
β : Type u_2
inst✝¹ : PseudoMetricSpace α
inst✝ : PseudoMetricSpace β
K : ℝ≥0
s : Set α
f : α → β
hf : LipschitzOnWith K f s
u : ℕ → α
hu : CauchySeq u
h'u : range u ⊆ s
b : ℕ → ℝ
b_nonneg : ∀ (n : ℕ), 0 ≤ b n
hb : ∀ (n m N : ℕ), N ≤ n → N ≤ m → dist (u n) (u m) ≤ b N
blim : Tendsto b atTop (nhds 0)
⊢ Tendsto (fun n ↦ ↑K * b n) atTop (nhds 0)
Module: Mathlib.Topology.MetricSpace.Gluing

Goal state before:
pp: ι : Type u_1
E : ι → Type u_2
inst✝ : (i : ι) → MetricSpace (E i)
i : ι
x y : E i
⊢ dist ⟨i, x⟩ ⟨i, y⟩ = dist x y

Tactic:
by
  simp [Dist.dist, Sigma.dist]

Goal state after:
Module: Mathlib.Topology.UnitInterval

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁴ : Field 𝕜
inst✝³ : LinearOrder 𝕜
inst✝² : IsStrictOrderedRing 𝕜
inst✝¹ : TopologicalSpace 𝕜
inst✝ : IsTopologicalRing 𝕜
a b : 𝕜
h : a < b
⊢ ↑(Icc a b) ≃ₜ ↑(Icc 0 1)

Tactic:
by
  let e := Homeomorph.image (affineHomeomorph (b - a) a (sub_pos.mpr h).ne.symm) (Set.Icc 0 1)
  refine (e.trans ?_).symm
  apply Homeomorph.setCongr
  rw [affineHomeomorph_image_I _ _ (sub_pos.2 h)]
  simp

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

Goal state before:

Tactic:
1 ≤ Sigma.dist ⟨i, x⟩ ⟨j, y⟩ := Sigma.one_le_dist_of_ne hij _ _
        _ < 1 := hy.trans_le (min_le_right _ _)

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

Goal state before:
pp: case refine_1
ι : Type u_1
E : ι → Type u_2
inst✝ : (i : ι) → MetricSpace (E i)
i : ι
x : E i
⊢ Sigma.dist ⟨i, x⟩ ⟨i, x⟩ = 0

Tactic:
simp [Sigma.dist]

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

Goal state before:
pp: case refine_3.inl
ι : Type u_1
E : ι → Type u_2
inst✝ : (i : ι) → MetricSpace (E i)
i : ι
x y : E i
⊢ Sigma.dist ⟨i, x⟩ ⟨i, y⟩ = 0 → ⟨i, x⟩ = ⟨i, y⟩

Tactic:
simp [Sigma.dist]

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

Goal state before:
pp: case mpr
α : Type u_1
inst✝ : TopologicalSpace α
s : Set α
β : Type
h : TopologicalSpace β
h' : PolishSpace β
f : β → α
f_cont : Continuous[h, inst✝] f
f_range : range f = s
⊢ AnalyticSet (range f)

Tactic:
exact analyticSet_range_of_polishSpace f_cont

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

Goal state before:
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 : f x ≠ f y
I2 : cylinder x (firstDiff x y) = cylinder y (firstDiff x y)
xs : x ∉ s
ys : y ∉ s
⊢ firstDiff x y ≤ firstDiff (f x) (f y)

Tactic:
have Ax : (s ∩ cylinder x (longestPrefix x s)).Nonempty :=
          inter_cylinder_longestPrefix_nonempty hs hne x

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 : f x ≠ f y
I2 : cylinder x (firstDiff x y) = cylinder y (firstDiff x y)
xs : x ∉ s
ys : y ∉ s
Ax : (s ∩ cylinder x (longestPrefix x s)).Nonempty
⊢ firstDiff x y ≤ firstDiff (f x) (f y)
Module: Mathlib.MeasureTheory.Measure.Dirac

Goal state before:
pp: α : Type u_1
inst✝¹ : MeasurableSpace α
inst✝ : Countable α
μ : Measure α
measurableAtoms : Set (Set α) := measurableAtom '' univ
h_nonempty : ∀ (s : ↑measurableAtoms), (↑s).Nonempty
points : ↑measurableAtoms → α := fun s ↦ ⋯.some
h_points_mem : ∀ (s : ↑measurableAtoms), points s ∈ ↑s
x : α
⊢ μ (measurableAtom x) = μ (measurableAtom ↑⟨points ⟨measurableAtom x, ⋯⟩, ⋯⟩) * 1 ↑⟨points ⟨measurableAtom x, ⋯⟩, ⋯⟩

Tactic:
simp only [Pi.one_apply, mul_one]
      congr 1
      refine (measurableAtom_eq_of_mem ?_).symm
      convert! h_points_mem _
      simp

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

Goal state before:
pp: X : Type u_3
Y : Type u_4
inst✝³ : TopologicalSpace X
inst✝² : TopologicalSpace Y
inst✝¹ : PolishSpace X
inst✝ : T2Space Y
s : Set Y
hs : AnalyticSet s
f : X → Y
hf : Continuous[inst✝³, inst✝²] f
⊢ AnalyticSet (f ⁻¹' s)

Tactic:
rcases analyticSet_iff_exists_polishSpace_range.1 hs with ⟨Z, _, _, g, hg, rfl⟩

Goal state after:
X : Type u_3
Y : Type u_4
inst✝³ : TopologicalSpace X
inst✝² : TopologicalSpace Y
inst✝¹ : PolishSpace X
inst✝ : T2Space Y
f : X → Y
hf : Continuous[inst✝³, inst✝²] f
Z : Type
w✝¹ : TopologicalSpace Z
w✝ : PolishSpace Z
g : Z → Y
hg : Continuous[w✝¹, inst✝²] g
hs : AnalyticSet (range g)
⊢ AnalyticSet (f ⁻¹' range g)
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: case succ
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
m n : ℕ
⊢ m + 1 ≤ n → (↑(p n)).2.1 m = (↑(p (m + 1))).2.1 m → (↑(p (n + 1))).2.1 m = (↑(p (m + 1))).2.1 m

Tactic:
hmn

Goal state after:
case succ
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
m n : ℕ
hmn : m + 1 ≤ n
⊢ (↑(p n)).2.1 m = (↑(p (m + 1))).2.1 m → (↑(p (n + 1))).2.1 m = (↑(p (m + 1))).2.1 m
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Countable

Goal state before:
pp: α : Type u_1
inst✝ : MeasurableSpace α
f : α → ℝ≥0∞
hf : Measurable f
⊢ ∫⁻ (a : α), f a ∂count = ∑' (a : α), f a

Tactic:
rw [count, lintegral_sum_measure]
  congr
  exact funext fun a => lintegral_dirac' a hf

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

Goal state before:
pp: α : Type u_1
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : MeasurableSingletonClass α
inst✝ : Fintype α
f : α → ℝ≥0∞
⊢ ∫⁻ (x : α), f x ∂μ = ∑ x, f x * μ {x}

Tactic:
← lintegral_finset,

Goal state after:
α : Type u_1
inst✝² : MeasurableSpace α
μ : Measure α
inst✝¹ : MeasurableSingletonClass α
inst✝ : Fintype α
f : α → ℝ≥0∞
⊢ ∫⁻ (x : α), f x ∂μ = ∫⁻ (x : α) in ↑Finset.univ, f x ∂μ
Module: Mathlib.MeasureTheory.Constructions.Polish.Basic

Goal state before:
pp: case succ
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
m n : ℕ
⊢ m + 1 ≤ n → (↑(p n)).2.2 m = (↑(p (m + 1))).2.2 m → (↑(p (n + 1))).2.2 m = (↑(p (m + 1))).2.2 m

Tactic:
hmn

Goal state after:
case succ
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
m n : ℕ
hmn : m + 1 ≤ n
⊢ (↑(p n)).2.2 m = (↑(p (m + 1))).2.2 m → (↑(p (n + 1))).2.2 m = (↑(p (m + 1))).2.2 m
Module: Mathlib.MeasureTheory.Integral.Lebesgue.Countable

Goal state before:
pp: case add
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∞
hL : L < ∫⁻ (x : α), ↑(f₁ x) ∂μ + ∫⁻ (x : α), ↑(f₂ x) ∂μ
⊢ ∃ g, (∀ (x : α), g x ≤ (f₁ + f₂) x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ

Tactic:
by_cases hf₁ : ∫⁻ x, f₁ x ∂μ = 0

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∞
hL : L < ∫⁻ (x : α), ↑(f₁ x) ∂μ + ∫⁻ (x : α), ↑(f₂ x) ∂μ
hf₁ : ∫⁻ (x : α), ↑(f₁ x) ∂μ = 0
⊢ ∃ g, (∀ (x : α), g x ≤ (f₁ + f₂) x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ

case neg
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∞
hL : L < ∫⁻ (x : α), ↑(f₁ x) ∂μ + ∫⁻ (x : α), ↑(f₂ x) ∂μ
hf₁ : ¬∫⁻ (x : α), ↑(f₁ x) ∂μ = 0
⊢ ∃ g, (∀ (x : α), g x ≤ (f₁ + f₂) x) ∧ ∫⁻ (x : α), ↑(g x) ∂μ < ∞ ∧ L < ∫⁻ (x : α), ↑(g x) ∂μ
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
⊢ μ (f '' U) ≠ 0

Tactic:
exact IsOpenPosMeasure.open_pos _ (hf.isOpen_iff_image_isOpen.mp hU) (Une.image f)

Goal state after:
Module: Mathlib.GroupTheory.Complement

Goal state before:
pp: G : Type u_1
inst✝ : Group G
H K : Subgroup G
h : H.IsComplement' K
⊢ K.IsComplement' H

Tactic:
by
  let ϕ : H × K ≃ K × H :=
    Equiv.mk (fun x => ⟨x.2⁻¹, x.1⁻¹⟩) (fun x => ⟨x.2⁻¹, x.1⁻¹⟩)
      (fun x => Prod.ext (inv_inv _) (inv_inv _)) fun x => Prod.ext (inv_inv _) (inv_inv _)
  let ψ : G ≃ G := Equiv.mk (fun g : G => g⁻¹) (fun g : G => g⁻¹) inv_inv inv_inv
  suffices hf : (ψ ∘ fun x : H × K => x.1.1 * x.2.1) = (fun x : K × H => x.1.1 * x.2.1) ∘ ϕ by
    rwa [isComplement'_def, isComplement_iff_bijective, ← Equiv.bijective_comp ϕ, ← hf,
      ψ.comp_bijective]
  exact funext fun x => mul_inv_rev _ _

Goal state after: