-- Mathlib/Topology/ContinuousMap/Bounded/Basic.lean
theorem arzela_ascoli₂ (s : Set β) (hs : IsCompact s) (A : Set (α →ᵇ β)) (closed : IsClosed A)
    (in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s) (H : Equicontinuous ((↑) : A → α → β)) :
    IsCompact A

Proof state:
case refine_2
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf✝ : f ∈ A
g : α →ᵇ ↑s := codRestrict s f ⋯
hf : F g ∈ A
⊢ F g ∈ comp Subtype.val M '' (F ⁻¹' A)

Tactic:
exact ⟨g, hf, rfl⟩

Result:
no goals

Proof state:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
⊢ IsCompact A

Tactic:
let F : (α →ᵇ s) → α →ᵇ β := comp (↑) M

Result:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
⊢ IsCompact A

Proof state:
case refine_2
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf : f ∈ A
g : α →ᵇ ↑s := codRestrict s f ⋯
⊢ f ∈ comp Subtype.val M '' (F ⁻¹' A)

Tactic:
rw [show f = F g by ext; rfl] at hf ⊢

Result:
case refine_2
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf✝ : f ∈ A
g : α →ᵇ ↑s := codRestrict s f ⋯
hf : F g ∈ A
⊢ F g ∈ comp Subtype.val M '' (F ⁻¹' A)

Proof state:
case refine_2
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf : f ∈ A
⊢ f ∈ comp Subtype.val M '' (F ⁻¹' A)

Tactic:
let g := codRestrict s f fun x => in_s f x hf

Result:
case refine_2
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf : f ∈ A
g : α →ᵇ ↑s := codRestrict s f ⋯
⊢ f ∈ comp Subtype.val M '' (F ⁻¹' A)

Proof state:
case refine_1
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
this : CompactSpace ↑s
⊢ Equicontinuous ((fun x => Subtype.val ∘ x) ∘ fun x => ⇑↑x)

Tactic:
exact H.comp (A.restrictPreimage F)

Result:
no goals

Proof state:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
⊢ IsCompact A

Tactic:
have M : LipschitzWith 1 Subtype.val := LipschitzWith.subtype_val s

Result:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
⊢ IsCompact A

Proof state:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf✝ : f ∈ A
g : α →ᵇ ↑s := codRestrict s f ⋯
hf : F g ∈ A
⊢ f = F g

Tactic:
ext

Result:
case h
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf✝ : f ∈ A
g : α →ᵇ ↑s := codRestrict s f ⋯
hf : F g ∈ A
x✝ : α
⊢ f x✝ = (F g) x✝

Proof state:
case refine_1
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
⊢ IsCompact (F ⁻¹' A)

Tactic:
haveI : CompactSpace s := isCompact_iff_compactSpace.1 hs

Result:
case refine_1
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
this : CompactSpace ↑s
⊢ IsCompact (F ⁻¹' A)

Proof state:
case refine_1
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
this : CompactSpace ↑s
⊢ Equicontinuous fun x => ⇑↑x

Tactic:
rw [isUniformEmbedding_subtype_val.isUniformInducing.equicontinuous_iff]

Result:
case refine_1
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
this : CompactSpace ↑s
⊢ Equicontinuous ((fun x => Subtype.val ∘ x) ∘ fun x => ⇑↑x)

Proof state:
case h
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : CompactSpace α
inst✝ : PseudoMetricSpace β
s : Set β
hs : IsCompact s
A : Set (α →ᵇ β)
closed : IsClosed A
in_s : ∀ (f : α →ᵇ β) (x : α), f ∈ A → f x ∈ s
H : Equicontinuous fun x => ⇑↑x
M : LipschitzWith 1 Subtype.val
F : (α →ᵇ ↑s) → α →ᵇ β := comp Subtype.val M
f : α →ᵇ β
hf✝ : f ∈ A
g : α →ᵇ ↑s := codRestrict s f ⋯
hf : F g ∈ A
x✝ : α
⊢ f x✝ = (F g) x✝

Tactic:
rfl

Result:
no goals