Theorem: MeasureTheory.tendsto_measure_Ioc_atBot
File: Mathlib/MeasureTheory/Measure/MeasureSpace.lean

Proof steps:
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
⊢ Tendsto (fun x => μ (Ioc x a)) atBot (𝓝 (μ (Iic a)))
state_after: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
⊢ Tendsto (fun x => μ (Ioc x a)) atBot (𝓝 (μ (Iic a)))
tactic: haveI : Nonempty α := ⟨a⟩
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
⊢ Tendsto (fun x => μ (Ioc x a)) atBot (𝓝 (μ (Iic a)))
state_after: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
⊢ Tendsto (fun x => μ (Ioc x a)) atBot (𝓝 (μ (Iic a)))
tactic: have h_mono : Antitone fun x => μ (Ioc x a) := fun i j hij => by simp only; gcongr
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
⊢ Tendsto (fun x => μ (Ioc x a)) atBot (𝓝 (μ (Iic a)))
state_after: case h.e'_5.h.e'_3
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
⊢ μ (Iic a) = ⨆ i, μ (Ioc i a)
tactic: convert tendsto_atBot_iSup h_mono
state_before: case h.e'_5.h.e'_3
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
⊢ μ (Iic a) = ⨆ i, μ (Ioc i a)
state_after: case h.e'_5.h.e'_3.intro.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
xs : ℕ → α
hxs_mono : Antitone xs
hxs_tendsto : Tendsto xs atTop atBot
⊢ μ (Iic a) = ⨆ i, μ (Ioc i a)
tactic: obtain ⟨xs, hxs_mono, hxs_tendsto⟩ := exists_seq_antitone_tendsto_atTop_atBot α
state_before: case h.e'_5.h.e'_3.intro.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
xs : ℕ → α
hxs_mono : Antitone xs
hxs_tendsto : Tendsto xs atTop atBot
⊢ μ (Iic a) = ⨆ i, μ (Ioc i a)
state_after: case h.e'_5.h.e'_3.intro.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
xs : ℕ → α
hxs_mono : Antitone xs
hxs_tendsto : Tendsto xs atTop atBot
h_Iic : Iic a = ⋃ n, Ioc (xs n) a
⊢ μ (Iic a) = ⨆ i, μ (Ioc i a)
tactic: have h_Iic : Iic a = ⋃ n, Ioc (xs n) a := by
    ext1 x
    simp only [mem_Iic, mem_iUnion, mem_Ioc, exists_and_right, iff_and_self]
    intro
    obtain ⟨y, hxy⟩ := NoMinOrder.exists_lt x
    obtain ⟨n, hn⟩ := tendsto_atTop_atBot.mp hxs_tendsto y
    exact ⟨n, (hn n le_rfl).trans_lt hxy⟩
state_before: case h.e'_5.h.e'_3.intro.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
xs : ℕ → α
hxs_mono : Antitone xs
hxs_tendsto : Tendsto xs atTop atBot
h_Iic : Iic a = ⋃ n, Ioc (xs n) a
⊢ μ (Iic a) = ⨆ i, μ (Ioc i a)
state_after: case h.e'_5.h.e'_3.intro.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
xs : ℕ → α
hxs_mono : Antitone xs
hxs_tendsto : Tendsto xs atTop atBot
h_Iic : Iic a = ⋃ n, Ioc (xs n) a
⊢ Directed (fun x x_1 => x ⊆ x_1) fun n => Ioc (xs n) a
tactic: rw [h_Iic, measure_iUnion_eq_iSup, iSup_eq_iSup_subseq_of_antitone h_mono hxs_tendsto]
state_before: case h.e'_5.h.e'_3.intro.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι : Type u_5
R : Type u_6
R' : Type u_7
m0 : MeasurableSpace α
inst✝⁴ : MeasurableSpace β
inst✝³ : MeasurableSpace γ
μ✝ μ₁ μ₂ μ₃ ν ν' ν₁ ν₂ : Measure α
s s' t : Set α
inst✝² : SemilatticeInf α
inst✝¹ : NoMinOrder α
inst✝ : atBot.IsCountablyGenerated
μ : Measure α
a : α
this : Nonempty α
h_mono : Antitone fun x => μ (Ioc x a)
xs : ℕ → α
hxs_mono : Antitone xs
hxs_tendsto : Tendsto xs atTop atBot
h_Iic : Iic a = ⋃ n, Ioc (xs n) a
⊢ Directed (fun x x_1 => x ⊆ x_1) fun n => Ioc (xs n) a
state_after: no goals
tactic: exact Monotone.directed_le fun i j hij => Ioc_subset_Ioc_left (hxs_mono hij)