Module: Mathlib.Topology.UniformSpace.UniformConvergenceTopology

Goal state before:
pp: case refine_2
α : Type u_1
β : Type u_2
inst✝ : UniformSpace β
𝔖 : Set (Set α)
δ₁ : Type u_5
δ₂ : Type u_6
φ₁ : δ₁ → α
φ₂ : δ₂ → α
𝔗₁ : Set (Set δ₁)
𝔗₂ : Set (Set δ₂)
h_image₁ : MapsTo (fun x ↦ φ₁ '' x) 𝔗₁ 𝔖
h_image₂ : MapsTo (fun x ↦ φ₂ '' x) 𝔗₂ 𝔖
h_preimage₁ : MapsTo (fun x ↦ φ₁ ⁻¹' x) 𝔖 𝔗₁
h_preimage₂ : MapsTo (fun x ↦ φ₂ ⁻¹' x) 𝔖 𝔗₂
h_cover : ∀ S ∈ 𝔖, S ⊆ range φ₁ ∪ range φ₂
ψ₁ : (S : Set α) → ↑(φ₁ ⁻¹' S) → ↑S := fun S ↦ S.restrictPreimage φ₁
ψ₂ : (S : Set α) → ↑(φ₂ ⁻¹' S) → ↑S := fun S ↦ S.restrictPreimage φ₂
this :
  ∀ S ∈ 𝔖,
    UniformFun.uniformSpace (↑S) β =
      UniformSpace.comap (fun x ↦ x ∘ ψ₁ S) (UniformFun.uniformSpace (↑(φ₁ ⁻¹' S)) β) ⊓
        UniformSpace.comap (fun x ↦ x ∘ ψ₂ S) (UniformFun.uniformSpace (↑(φ₂ ⁻¹' S)) β)
⊢ uniformSpace α β 𝔖 ≤ UniformSpace.comap (⇑(ofFun 𝔗₂) ∘ (fun x ↦ x ∘ φ₂) ∘ ⇑(toFun 𝔖)) (uniformSpace δ₂ β 𝔗₂)

pp: case refine_3
α : Type u_1
β : Type u_2
inst✝ : UniformSpace β
𝔖 : Set (Set α)
δ₁ : Type u_5
δ₂ : Type u_6
φ₁ : δ₁ → α
φ₂ : δ₂ → α
𝔗₁ : Set (Set δ₁)
𝔗₂ : Set (Set δ₂)
h_image₁ : MapsTo (fun x ↦ φ₁ '' x) 𝔗₁ 𝔖
h_image₂ : MapsTo (fun x ↦ φ₂ '' x) 𝔗₂ 𝔖
h_preimage₁ : MapsTo (fun x ↦ φ₁ ⁻¹' x) 𝔖 𝔗₁
h_preimage₂ : MapsTo (fun x ↦ φ₂ ⁻¹' x) 𝔖 𝔗₂
h_cover : ∀ S ∈ 𝔖, S ⊆ range φ₁ ∪ range φ₂
ψ₁ : (S : Set α) → ↑(φ₁ ⁻¹' S) → ↑S := fun S ↦ S.restrictPreimage φ₁
ψ₂ : (S : Set α) → ↑(φ₂ ⁻¹' S) → ↑S := fun S ↦ S.restrictPreimage φ₂
this :
  ∀ S ∈ 𝔖,
    UniformFun.uniformSpace (↑S) β =
      UniformSpace.comap (fun x ↦ x ∘ ψ₁ S) (UniformFun.uniformSpace (↑(φ₁ ⁻¹' S)) β) ⊓
        UniformSpace.comap (fun x ↦ x ∘ ψ₂ S) (UniformFun.uniformSpace (↑(φ₂ ⁻¹' S)) β)
S : Set α
hS : S ∈ 𝔖
⊢ UniformSpace.comap (⇑(ofFun 𝔗₁) ∘ (fun x ↦ x ∘ φ₁) ∘ ⇑(toFun 𝔖)) (uniformSpace δ₁ β 𝔗₁) ⊓
      UniformSpace.comap (⇑(ofFun 𝔗₂) ∘ (fun x ↦ x ∘ φ₂) ∘ ⇑(toFun 𝔖)) (uniformSpace δ₂ β 𝔗₂) ≤
    UniformSpace.comap (⇑UniformFun.ofFun ∘ S.domRestrict ∘ ⇑(toFun 𝔖)) (UniformFun.uniformSpace (↑S) β)

Tactic:
· rw [← uniformContinuous_iff_le_comap]
    exact UniformOnFun.precomp_uniformContinuous h_image₂

Goal state after:
case refine_3
α : Type u_1
β : Type u_2
inst✝ : UniformSpace β
𝔖 : Set (Set α)
δ₁ : Type u_5
δ₂ : Type u_6
φ₁ : δ₁ → α
φ₂ : δ₂ → α
𝔗₁ : Set (Set δ₁)
𝔗₂ : Set (Set δ₂)
h_image₁ : MapsTo (fun x ↦ φ₁ '' x) 𝔗₁ 𝔖
h_image₂ : MapsTo (fun x ↦ φ₂ '' x) 𝔗₂ 𝔖
h_preimage₁ : MapsTo (fun x ↦ φ₁ ⁻¹' x) 𝔖 𝔗₁
h_preimage₂ : MapsTo (fun x ↦ φ₂ ⁻¹' x) 𝔖 𝔗₂
h_cover : ∀ S ∈ 𝔖, S ⊆ range φ₁ ∪ range φ₂
ψ₁ : (S : Set α) → ↑(φ₁ ⁻¹' S) → ↑S := fun S ↦ S.restrictPreimage φ₁
ψ₂ : (S : Set α) → ↑(φ₂ ⁻¹' S) → ↑S := fun S ↦ S.restrictPreimage φ₂
this :
  ∀ S ∈ 𝔖,
    UniformFun.uniformSpace (↑S) β =
      UniformSpace.comap (fun x ↦ x ∘ ψ₁ S) (UniformFun.uniformSpace (↑(φ₁ ⁻¹' S)) β) ⊓
        UniformSpace.comap (fun x ↦ x ∘ ψ₂ S) (UniformFun.uniformSpace (↑(φ₂ ⁻¹' S)) β)
S : Set α
hS : S ∈ 𝔖
⊢ UniformSpace.comap (⇑(ofFun 𝔗₁) ∘ (fun x ↦ x ∘ φ₁) ∘ ⇑(toFun 𝔖)) (uniformSpace δ₁ β 𝔗₁) ⊓
      UniformSpace.comap (⇑(ofFun 𝔗₂) ∘ (fun x ↦ x ∘ φ₂) ∘ ⇑(toFun 𝔖)) (uniformSpace δ₂ β 𝔗₂) ≤
    UniformSpace.comap (⇑UniformFun.ofFun ∘ S.domRestrict ∘ ⇑(toFun 𝔖)) (UniformFun.uniformSpace (↑S) β)