Theorem: measurable_iSup
File: Mathlib/MeasureTheory/Constructions/BorelSpace/Order.lean

tactic: rcases isEmpty_or_nonempty ι with hι|hι
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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)
⊢ Measurable fun b => ⨆ i, f i b
state_after: case inl
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 : IsEmpty ι
⊢ Measurable fun b => ⨆ i, f i b

case inr
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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
⊢ Measurable fun b => ⨆ i, f i b

tactic: have A : MeasurableSet {b | BddAbove (range (fun i ↦ f i b))} :=
  measurableSet_bddAbove_range hf
state_before: case inr
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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
⊢ Measurable fun b => ⨆ i, f i b
state_after: case inr
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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
state_before: case inr
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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
state_after: case inr
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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

tactic: apply Measurable.isLUB_of_mem hf A _ _ this
state_before: case inr
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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
state_after: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
⊢ ∀ b ∈ {b | BddAbove (range fun i => f i b)}, IsLUB {a | ∃ i, f i b = a} (⨆ i, f i b)

α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
⊢ EqOn (fun b => ⨆ i, f i b) (fun _b => sSup ∅) {b | BddAbove (range fun i => f i b)}ᶜ

tactic: simp [iSup_of_empty']
state_before: case inl
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 : IsEmpty ι
⊢ Measurable fun b => ⨆ i, f i b
state_after: no goals

tactic: rintro b ⟨c, hc⟩
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
⊢ ∀ b ∈ {b | BddAbove (range fun i => f i b)}, IsLUB {a | ∃ i, f i b = a} (⨆ i, f i b)
state_after: case intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
⊢ IsLUB {a | ∃ i, f i b = a} (⨆ i, f i b)

tactic: apply isLUB_ciSup
state_before: case intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
⊢ IsLUB {a | ∃ i, f i b = a} (⨆ i, f i b)
state_after: case intro.H
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
⊢ BddAbove (range fun y => f y b)

tactic: refine ⟨c, ?_⟩
state_before: case intro.H
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
⊢ BddAbove (range fun y => f y b)
state_after: case intro.H
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
⊢ c ∈ upperBounds (range fun y => f y b)

tactic: rintro d ⟨i, rfl⟩
state_before: case intro.H
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
⊢ c ∈ upperBounds (range fun y => f y b)
state_after: case intro.H.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
i : ι
⊢ (fun y => f y b) i ≤ c

tactic: exact hc (mem_range_self i)
state_before: case intro.H.intro
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
c : α
hc : c ∈ upperBounds (range fun i => f i b)
i : ι
⊢ (fun y => f y b) i ≤ c
state_after: no goals

tactic: intro b hb
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
⊢ EqOn (fun b => ⨆ i, f i b) (fun _b => sSup ∅) {b | BddAbove (range fun i => f i b)}ᶜ
state_after: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
hb : b ∈ {b | BddAbove (range fun i => f i b)}ᶜ
⊢ (fun b => ⨆ i, f i b) b = (fun _b => sSup ∅) b

tactic: apply csSup_of_not_bddAbove
state_before: α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
hb : b ∈ {b | BddAbove (range fun i => f i b)}ᶜ
⊢ (fun b => ⨆ i, f i b) b = (fun _b => sSup ∅) b
state_after: case hs
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
hb : b ∈ {b | BddAbove (range fun i => f i b)}ᶜ
⊢ ¬BddAbove (range fun i => f i b)

tactic: exact hb
state_before: case hs
α : Type u_1
β : Type u_2
γ : Type u_3
δ : Type u_4
ι✝ : Sort y
s t u : Set α
inst✝¹⁰ : TopologicalSpace α
inst✝⁹ : MeasurableSpace α
inst✝⁸ : BorelSpace α
inst✝⁷ : TopologicalSpace β
inst✝⁶ : MeasurableSpace β
inst✝⁵ : BorelSpace β
inst✝⁴ : 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 ∅
b : δ
hb : b ∈ {b | BddAbove (range fun i => f i b)}ᶜ
⊢ ¬BddAbove (range fun i => f i b)
state_after: no goals