Theorem: ProbabilityTheory.measurableSet_isRatStieltjesPoint
File: Mathlib/Probability/Kernel/Disintegration/MeasurableStieltjes.lean

Proof steps:
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
tactic: have h1 : MeasurableSet {a | Monotone (f a)} := by
    change MeasurableSet {a | ∀ q r (_ : q ≤ r), f a q ≤ f a r}
    simp_rw [Set.setOf_forall]
    refine MeasurableSet.iInter (fun q ↦ ?_)
    refine MeasurableSet.iInter (fun r ↦ ?_)
    refine MeasurableSet.iInter (fun _ ↦ ?_)
    exact measurableSet_le hf.eval hf.eval
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
tactic: have h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)} :=
    measurableSet_tendsto _ (fun q ↦ hf.eval)
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
tactic: have h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)} :=
    measurableSet_tendsto _ (fun q ↦ hf.eval)
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
tactic: have h4 : MeasurableSet {a | ∀ t : ℚ, ⨅ r : Ioi t, f a r = f a t} := by
    rw [Set.setOf_forall]
    refine MeasurableSet.iInter (fun q ↦ ?_)
    exact measurableSet_eq_fun (measurable_iInf fun _ ↦ hf.eval) hf.eval
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
⊢ MeasurableSet {a | IsRatStieltjesPoint f a}
state_after: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
⊢ {a | IsRatStieltjesPoint f a} =
    {a | Monotone (f a)} ∩ {a | Tendsto (f a) atTop (𝓝 1)} ∩ {a | Tendsto (f a) atBot (𝓝 0)} ∩
      {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
tactic: suffices {a | IsRatStieltjesPoint f a}
      = ({a | Monotone (f a)} ∩ {a | Tendsto (f a) atTop (𝓝 1)} ∩ {a | Tendsto (f a) atBot (𝓝 0)}
        ∩ {a | ∀ t : ℚ, ⨅ r : Ioi t, f a r = f a t}) by
    rw [this]
    exact (((h1.inter h2).inter h3).inter h4)
state_before: α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
⊢ {a | IsRatStieltjesPoint f a} =
    {a | Monotone (f a)} ∩ {a | Tendsto (f a) atTop (𝓝 1)} ∩ {a | Tendsto (f a) atBot (𝓝 0)} ∩
      {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
state_after: case h
α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
a : α
⊢ a ∈ {a | IsRatStieltjesPoint f a} ↔
    a ∈
      {a | Monotone (f a)} ∩ {a | Tendsto (f a) atTop (𝓝 1)} ∩ {a | Tendsto (f a) atBot (𝓝 0)} ∩
        {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
tactic: ext a
state_before: case h
α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
a : α
⊢ a ∈ {a | IsRatStieltjesPoint f a} ↔
    a ∈
      {a | Monotone (f a)} ∩ {a | Tendsto (f a) atTop (𝓝 1)} ∩ {a | Tendsto (f a) atBot (𝓝 0)} ∩
        {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
state_after: case h
α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
a : α
⊢ IsRatStieltjesPoint f a ↔
    ((Monotone (f a) ∧ Tendsto (f a) atTop (𝓝 1)) ∧ Tendsto (f a) atBot (𝓝 0)) ∧ ∀ (t : ℚ), ⨅ r, f a ↑r = f a t
tactic: simp only [mem_setOf_eq, mem_inter_iff]
state_before: case h
α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
a : α
⊢ IsRatStieltjesPoint f a ↔
    ((Monotone (f a) ∧ Tendsto (f a) atTop (𝓝 1)) ∧ Tendsto (f a) atBot (𝓝 0)) ∧ ∀ (t : ℚ), ⨅ r, f a ↑r = f a t
state_after: case h.refine_1
α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
a : α
h : IsRatStieltjesPoint f a
⊢ ((Monotone (f a) ∧ Tendsto (f a) atTop (𝓝 1)) ∧ Tendsto (f a) atBot (𝓝 0)) ∧ ∀ (t : ℚ), ⨅ r, f a ↑r = f a t

case h.refine_2
α : Type u_1
β : Type u_2
ι : Type u_3
inst✝ : MeasurableSpace α
f : α → ℚ → ℝ
hf : Measurable f
h1 : MeasurableSet {a | Monotone (f a)}
h2 : MeasurableSet {a | Tendsto (f a) atTop (𝓝 1)}
h3 : MeasurableSet {a | Tendsto (f a) atBot (𝓝 0)}
h4 : MeasurableSet {a | ∀ (t : ℚ), ⨅ r, f a ↑r = f a t}
a : α
h : ((Monotone (f a) ∧ Tendsto (f a) atTop (𝓝 1)) ∧ Tendsto (f a) atBot (𝓝 0)) ∧ ∀ (t : ℚ), ⨅ r, f a ↑r = f a t
⊢ IsRatStieltjesPoint f a
tactic: refine ⟨fun h ↦ ?_, fun h ↦ ?_⟩