-- Mathlib/Topology/Algebra/Module/StrongTopology.lean
theorem t2Space [TopologicalSpace F] [IsTopologicalAddGroup F] [T2Space F]
    (𝔖 : Set (Set E)) (h𝔖 : ⋃₀ 𝔖 = univ) : T2Space (UniformConvergenceCLM σ F 𝔖)

Proof state:
𝕜₁ : Type u_1
𝕜₂ : Type u_2
inst✝⁹ : NormedField 𝕜₁
inst✝⁸ : NormedField 𝕜₂
σ : 𝕜₁ →+* 𝕜₂
E : Type u_3
F : Type u_4
inst✝⁷ : AddCommGroup E
inst✝⁶ : Module 𝕜₁ E
inst✝⁵ : TopologicalSpace E
inst✝⁴ : AddCommGroup F
inst✝³ : Module 𝕜₂ F
inst✝² : TopologicalSpace F
inst✝¹ : IsTopologicalAddGroup F
inst✝ : T2Space F
𝔖 : Set (Set E)
h𝔖 : ⋃₀ 𝔖 = univ
⊢ T2Space (UniformConvergenceCLM σ F 𝔖)

Tactic:
letI : UniformSpace F := IsTopologicalAddGroup.toUniformSpace F

Result:
𝕜₁ : Type u_1
𝕜₂ : Type u_2
inst✝⁹ : NormedField 𝕜₁
inst✝⁸ : NormedField 𝕜₂
σ : 𝕜₁ →+* 𝕜₂
E : Type u_3
F : Type u_4
inst✝⁷ : AddCommGroup E
inst✝⁶ : Module 𝕜₁ E
inst✝⁵ : TopologicalSpace E
inst✝⁴ : AddCommGroup F
inst✝³ : Module 𝕜₂ F
inst✝² : TopologicalSpace F
inst✝¹ : IsTopologicalAddGroup F
inst✝ : T2Space F
𝔖 : Set (Set E)
h𝔖 : ⋃₀ 𝔖 = univ
this : UniformSpace F := IsTopologicalAddGroup.toUniformSpace F
⊢ T2Space (UniformConvergenceCLM σ F 𝔖)

Proof state:
𝕜₁ : Type u_1
𝕜₂ : Type u_2
inst✝⁹ : NormedField 𝕜₁
inst✝⁸ : NormedField 𝕜₂
σ : 𝕜₁ →+* 𝕜₂
E : Type u_3
F : Type u_4
inst✝⁷ : AddCommGroup E
inst✝⁶ : Module 𝕜₁ E
inst✝⁵ : TopologicalSpace E
inst✝⁴ : AddCommGroup F
inst✝³ : Module 𝕜₂ F
inst✝² : TopologicalSpace F
inst✝¹ : IsTopologicalAddGroup F
inst✝ : T2Space F
𝔖 : Set (Set E)
h𝔖 : ⋃₀ 𝔖 = univ
this✝¹ : UniformSpace F := IsTopologicalAddGroup.toUniformSpace F
this✝ : UniformAddGroup F
this : T2Space (E →ᵤ[𝔖] F)
⊢ T2Space (UniformConvergenceCLM σ F 𝔖)

Tactic:
exact (isEmbedding_coeFn σ F 𝔖).t2Space

Result:
no goals

Proof state:
𝕜₁ : Type u_1
𝕜₂ : Type u_2
inst✝⁹ : NormedField 𝕜₁
inst✝⁸ : NormedField 𝕜₂
σ : 𝕜₁ →+* 𝕜₂
E : Type u_3
F : Type u_4
inst✝⁷ : AddCommGroup E
inst✝⁶ : Module 𝕜₁ E
inst✝⁵ : TopologicalSpace E
inst✝⁴ : AddCommGroup F
inst✝³ : Module 𝕜₂ F
inst✝² : TopologicalSpace F
inst✝¹ : IsTopologicalAddGroup F
inst✝ : T2Space F
𝔖 : Set (Set E)
h𝔖 : ⋃₀ 𝔖 = univ
this : UniformSpace F := IsTopologicalAddGroup.toUniformSpace F
⊢ T2Space (UniformConvergenceCLM σ F 𝔖)

Tactic:
haveI : UniformAddGroup F := uniformAddGroup_of_addCommGroup

Result:
𝕜₁ : Type u_1
𝕜₂ : Type u_2
inst✝⁹ : NormedField 𝕜₁
inst✝⁸ : NormedField 𝕜₂
σ : 𝕜₁ →+* 𝕜₂
E : Type u_3
F : Type u_4
inst✝⁷ : AddCommGroup E
inst✝⁶ : Module 𝕜₁ E
inst✝⁵ : TopologicalSpace E
inst✝⁴ : AddCommGroup F
inst✝³ : Module 𝕜₂ F
inst✝² : TopologicalSpace F
inst✝¹ : IsTopologicalAddGroup F
inst✝ : T2Space F
𝔖 : Set (Set E)
h𝔖 : ⋃₀ 𝔖 = univ
this✝ : UniformSpace F := IsTopologicalAddGroup.toUniformSpace F
this : UniformAddGroup F
⊢ T2Space (UniformConvergenceCLM σ F 𝔖)

Proof state:
𝕜₁ : Type u_1
𝕜₂ : Type u_2
inst✝⁹ : NormedField 𝕜₁
inst✝⁸ : NormedField 𝕜₂
σ : 𝕜₁ →+* 𝕜₂
E : Type u_3
F : Type u_4
inst✝⁷ : AddCommGroup E
inst✝⁶ : Module 𝕜₁ E
inst✝⁵ : TopologicalSpace E
inst✝⁴ : AddCommGroup F
inst✝³ : Module 𝕜₂ F
inst✝² : TopologicalSpace F
inst✝¹ : IsTopologicalAddGroup F
inst✝ : T2Space F
𝔖 : Set (Set E)
h𝔖 : ⋃₀ 𝔖 = univ
this✝ : UniformSpace F := IsTopologicalAddGroup.toUniformSpace F
this : UniformAddGroup F
⊢ T2Space (UniformConvergenceCLM σ F 𝔖)

Tactic:
haveI : T2Space (E →ᵤ[𝔖] F) := UniformOnFun.t2Space_of_covering h𝔖

Result:
𝕜₁ : Type u_1
𝕜₂ : Type u_2
inst✝⁹ : NormedField 𝕜₁
inst✝⁸ : NormedField 𝕜₂
σ : 𝕜₁ →+* 𝕜₂
E : Type u_3
F : Type u_4
inst✝⁷ : AddCommGroup E
inst✝⁶ : Module 𝕜₁ E
inst✝⁵ : TopologicalSpace E
inst✝⁴ : AddCommGroup F
inst✝³ : Module 𝕜₂ F
inst✝² : TopologicalSpace F
inst✝¹ : IsTopologicalAddGroup F
inst✝ : T2Space F
𝔖 : Set (Set E)
h𝔖 : ⋃₀ 𝔖 = univ
this✝¹ : UniformSpace F := IsTopologicalAddGroup.toUniformSpace F
this✝ : UniformAddGroup F
this : T2Space (E →ᵤ[𝔖] F)
⊢ T2Space (UniformConvergenceCLM σ F 𝔖)