Theorem: refinement_of_locallyCompact_sigmaCompact_of_nhds_basis_set
File: Mathlib/Topology/Compactness/Paracompact.lean

tactic: set K' : CompactExhaustion X := CompactExhaustion.choice X
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: set K : CompactExhaustion X := K'.shiftr.shiftr
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: set Kdiff := fun n ↦ K (n + 1) \ interior (K n)
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: have hKcov : ∀ x, x ∈ Kdiff (K'.find x + 1) := fun x ↦ by
  simpa only [K'.find_shiftr] using
    diff_subset_diff_right interior_subset (K'.shiftr.mem_diff_shiftr_find x)
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: have Kdiffc : ∀ n, IsCompact (Kdiff n ∩ s) :=
  fun n ↦ ((K.isCompact _).diff isOpen_interior).inter_right hs
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: have : ∀ (n) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 (x : X) :=
  fun n x ↦ (K.isClosed n).compl_mem_nhds fun hx' ↦ x.2.1.2 <| K.subset_interior_succ _ hx'
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: choose! r hrp hr using fun n (x : ↑(Kdiff (n + 1) ∩ s)) ↦ (hB x x.2.2).mem_iff.1 (this n x)
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: have hxr : ∀ (n x) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x := fun n x hx ↦
  (hB x hx.2).mem_of_mem (hrp _ ⟨x, hx⟩)
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: choose T hT using fun n ↦ (Kdiffc (n + 1)).elim_nhds_subcover' _ (hxr n)
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: set T' : ∀ n, Set ↑(Kdiff (n + 1) ∩ s) := fun n ↦ T n
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)

tactic: refine ⟨Σn, T' n, fun a ↦ a.2, fun a ↦ r a.1 a.2, ?_, ?_, ?_⟩
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ ∃ α c r, (∀ (a : α), c a ∈ s ∧ p (c a) (r a)) ∧ s ⊆ ⋃ a, B (c a) (r a) ∧ LocallyFinite fun a => B (c a) (r a)
state_after: case refine_1
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ ∀ (a : (n : ℕ) × ↑(T' n)), (fun a => ↑↑a.snd) a ∈ s ∧ p ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)

case refine_2
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ s ⊆ ⋃ a, B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)

case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ LocallyFinite fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)

tactic: simpa only [K'.find_shiftr] using
  diff_subset_diff_right interior_subset (K'.shiftr.mem_diff_shiftr_find x)
state_before: ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
x : X
⊢ x ∈ Kdiff (K'.find x + 1)
state_after: no goals

tactic: rintro ⟨n, x, hx⟩
state_before: case refine_1
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ ∀ (a : (n : ℕ) × ↑(T' n)), (fun a => ↑↑a.snd) a ∈ s ∧ p ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)
state_after: case refine_1.mk.mk
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
n : ℕ
x : ↑(Kdiff (n + 1) ∩ s)
hx : x ∈ T' n
⊢ (fun a => ↑↑a.snd) ⟨n, ⟨x, hx⟩⟩ ∈ s ∧ p ((fun a => ↑↑a.snd) ⟨n, ⟨x, hx⟩⟩) ((fun a => r a.fst ↑a.snd) ⟨n, ⟨x, hx⟩⟩)

tactic: exact ⟨x.2.2, hrp _ _⟩
state_before: case refine_1.mk.mk
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
n : ℕ
x : ↑(Kdiff (n + 1) ∩ s)
hx : x ∈ T' n
⊢ (fun a => ↑↑a.snd) ⟨n, ⟨x, hx⟩⟩ ∈ s ∧ p ((fun a => ↑↑a.snd) ⟨n, ⟨x, hx⟩⟩) ((fun a => r a.fst ↑a.snd) ⟨n, ⟨x, hx⟩⟩)
state_after: no goals

tactic: refine fun x hx ↦ mem_iUnion.2 ?_
state_before: case refine_2
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ s ⊆ ⋃ a, B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)
state_after: case refine_2
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
hx : x ∈ s
⊢ ∃ i, x ∈ B ((fun a => ↑↑a.snd) i) ((fun a => r a.fst ↑a.snd) i)

tactic: rcases mem_iUnion₂.1 (hT _ ⟨hKcov x, hx⟩) with ⟨⟨c, hc⟩, hcT, hcx⟩
state_before: case refine_2
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
hx : x ∈ s
⊢ ∃ i, x ∈ B ((fun a => ↑↑a.snd) i) ((fun a => r a.fst ↑a.snd) i)
state_after: case refine_2.intro.mk.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
hx : x ∈ s
c : X
hc : c ∈ Kdiff (K'.find x + 1) ∩ s
hcT : ⟨c, hc⟩ ∈ T (K'.find x)
hcx : x ∈ B (↑⟨c, hc⟩) (r (K'.find x) ⟨↑⟨c, hc⟩, ⋯⟩)
⊢ ∃ i, x ∈ B ((fun a => ↑↑a.snd) i) ((fun a => r a.fst ↑a.snd) i)

tactic: exact ⟨⟨_, ⟨c, hc⟩, hcT⟩, hcx⟩
state_before: case refine_2.intro.mk.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
hx : x ∈ s
c : X
hc : c ∈ Kdiff (K'.find x + 1) ∩ s
hcT : ⟨c, hc⟩ ∈ T (K'.find x)
hcx : x ∈ B (↑⟨c, hc⟩) (r (K'.find x) ⟨↑⟨c, hc⟩, ⋯⟩)
⊢ ∃ i, x ∈ B ((fun a => ↑↑a.snd) i) ((fun a => r a.fst ↑a.snd) i)
state_after: no goals

tactic: intro x
state_before: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
⊢ LocallyFinite fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)
state_after: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
⊢ ∃ t ∈ 𝓝 x, {i | ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩ t).Nonempty}.Finite

tactic: refine
  ⟨interior (K (K'.find x + 3)),
    IsOpen.mem_nhds isOpen_interior (K.subset_interior_succ _ (hKcov x).1), ?_⟩
state_before: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
⊢ ∃ t ∈ 𝓝 x, {i | ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩ t).Nonempty}.Finite
state_after: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
⊢ {i |
      ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩
          interior (K (K'.find x + 3))).Nonempty}.Finite

tactic: have : (⋃ k ≤ K'.find x + 2, range (Sigma.mk k) : Set (Σn, T' n)).Finite :=
  (finite_le_nat _).biUnion fun k _ ↦ finite_range _
state_before: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
⊢ {i |
      ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩
          interior (K (K'.find x + 3))).Nonempty}.Finite
state_after: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
⊢ {i |
      ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩
          interior (K (K'.find x + 3))).Nonempty}.Finite

tactic: apply this.subset
state_before: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
⊢ {i |
      ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩
          interior (K (K'.find x + 3))).Nonempty}.Finite
state_after: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
⊢ {i | ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩ interior (K (K'.find x + 3))).Nonempty} ⊆
    ⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)

tactic: rintro ⟨k, c, hc⟩
state_before: case refine_3
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
⊢ {i | ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩ interior (K (K'.find x + 3))).Nonempty} ⊆
    ⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)
state_after: case refine_3.mk.mk
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
⊢ ⟨k, ⟨c, hc⟩⟩ ∈
      {i |
        ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩ interior (K (K'.find x + 3))).Nonempty} →
    ⟨k, ⟨c, hc⟩⟩ ∈ ⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)

tactic: simp only [mem_iUnion, mem_setOf_eq, mem_image, Subtype.coe_mk]
state_before: case refine_3.mk.mk
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
⊢ ⟨k, ⟨c, hc⟩⟩ ∈
      {i |
        ((fun a => B ((fun a => ↑↑a.snd) a) ((fun a => r a.fst ↑a.snd) a)) i ∩ interior (K (K'.find x + 3))).Nonempty} →
    ⟨k, ⟨c, hc⟩⟩ ∈ ⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)
state_after: case refine_3.mk.mk
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
⊢ (B (↑c) (r k c) ∩ interior (K (K'.find x + 3))).Nonempty →
    ∃ i, ∃ (_ : i ≤ K'.find x + 2), ⟨k, ⟨c, hc⟩⟩ ∈ range (Sigma.mk i)

tactic: rintro ⟨x, hxB : x ∈ B c (r k c), hxK⟩
state_before: case refine_3.mk.mk
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
⊢ (B (↑c) (r k c) ∩ interior (K (K'.find x + 3))).Nonempty →
    ∃ i, ∃ (_ : i ≤ K'.find x + 2), ⟨k, ⟨c, hc⟩⟩ ∈ range (Sigma.mk i)
state_after: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
⊢ ∃ i, ∃ (_ : i ≤ K'.find x✝ + 2), ⟨k, ⟨c, hc⟩⟩ ∈ range (Sigma.mk i)

tactic: refine ⟨k, ?_, ⟨c, hc⟩, rfl⟩
state_before: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
⊢ ∃ i, ∃ (_ : i ≤ K'.find x✝ + 2), ⟨k, ⟨c, hc⟩⟩ ∈ range (Sigma.mk i)
state_after: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
⊢ k ≤ K'.find x✝ + 2

tactic: have := (mem_compl_iff _ _).1 (hr k c hxB)
state_before: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
⊢ k ≤ K'.find x✝ + 2
state_after: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝¹ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this✝ : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
this : x ∉ K k
⊢ k ≤ K'.find x✝ + 2

tactic: contrapose! this with hnk
state_before: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝¹ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this✝ : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
this : x ∉ K k
⊢ k ≤ K'.find x✝ + 2
state_after: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
hnk : K'.find x✝ + 2 < k
⊢ x ∈ K k

tactic: exact K.subset hnk (interior_subset hxK)
state_before: case refine_3.mk.mk.intro.intro
ι✝ : Type u
X : Type v
Y : Type w
inst✝⁴ : TopologicalSpace X
inst✝³ : TopologicalSpace Y
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n => K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this✝ : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n => ↑(T n)
x✝ : X
this : (⋃ k, ⋃ (_ : k ≤ K'.find x✝ + 2), range (Sigma.mk k)).Finite
k : ℕ
c : ↑(Kdiff (k + 1) ∩ s)
hc : c ∈ T' k
x : X
hxB : x ∈ B (↑c) (r k c)
hxK : x ∈ interior (K (K'.find x✝ + 3))
hnk : K'.find x✝ + 2 < k
⊢ x ∈ K k
state_after: no goals