mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Unital

Goal state before:
pp: R : Type u_1
A : Type u_2
p : A → Prop
inst✝¹⁰ : Semifield R
inst✝⁹ : StarRing R
inst✝⁸ : MetricSpace R
inst✝⁷ : IsTopologicalSemiring R
inst✝⁶ : ContinuousStar R
inst✝⁵ : TopologicalSpace A
inst✝⁴ : Ring A
inst✝³ : StarRing A
inst✝² : Algebra R A
inst✝¹ : ContinuousFunctionalCalculus R A p
inst✝ : ContinuousInv₀ R
f : R → R
a : A
hf' : ∀ x ∈ spectrum R a, f x ≠ 0
hf : ContinuousOn f (spectrum R a)
ha : p a
⊢ cfc (fun x ↦ (f x)⁻¹ * f x) a = cfc 1 a

Tactic:
exact cfc_congr fun _ _ ↦ by aesop

Goal state after:
Module: Mathlib.Topology.ContinuousMap.Polynomial

Goal state before:
pp: R : Type u_1
inst✝⁷ : CommSemiring R
inst✝⁶ : TopologicalSpace R
inst✝⁵ : IsTopologicalSemiring R
A : Type u_2
inst✝⁴ : StarRing R
inst✝³ : ContinuousStar R
inst✝² : Semiring A
inst✝¹ : StarRing A
inst✝ : Algebra R A
s : Set R
φ ψ : C(↑s, R) →⋆ₐ[R] A
h : φ ((toContinuousMapOnAlgHom s) X) = ψ ((toContinuousMapOnAlgHom s) X)
⊢ (polynomialFunctions s).starClosure ≤ StarAlgHom.equalizer φ ψ

Tactic:
rw [polynomialFunctions.starClosure_eq_adjoin_X s]
  exact StarAlgHom.adjoin_le_equalizer φ ψ fun x hx => (Set.mem_singleton_iff.1 hx).symm ▸ h

Goal state after:
Module: Mathlib.Analysis.SpecialFunctions.Bernstein

Goal state before:
pp: E : Type u_1
inst✝⁵ : AddCommGroup E
inst✝⁴ : TopologicalSpace E
inst✝³ : IsTopologicalAddGroup E
inst✝² : Module ℝ E
inst✝¹ : ContinuousSMul ℝ E
inst✝ : LocallyConvexSpace ℝ E
f : C(↑I, E)
this✝ : UniformSpace E := IsTopologicalAddGroup.rightUniformSpace E
this : IsUniformAddGroup E
U : Set E
hU₀ : U ∈ 𝓝 0
hUc : Convex ℝ U
C : ℝ
hC : ∀ (x y : ↑I), gauge U (f x - f y) ≤ C
hC₀ : 0 ≤ C
δ : ℝ
hδ₀ : δ > 0
hδ : ∀ (x y : ↑I), dist x y < δ → gauge U (f x - f y) < 1 / 2
nhds_zero : Tendsto (fun n ↦ C / δ ^ 2 / ↑n) atTop (𝓝 0)
n : ℕ
nh : C / δ ^ 2 / ↑n < 1 / 2
hn₀ : n ≠ 0
x : ↑I
S : Finset (Fin (n + 1)) := {k | dist k/ₙ x < δ}
⊢ C / δ ^ 2 * 1 * 1 / ↑n < 1 / 2

Tactic:
simpa only [mul_one]

Goal state after:
Module: Mathlib.Topology.ContinuousMap.StoneWeierstrass

Goal state before:
pp: X : Type u_2
inst✝ : TopologicalSpace X
A : Subalgebra ℝ C(X, ℝ)
hA : A.SeparatesPoints
f : C(X, ℝ)
K : Set X
hK : IsCompact K
ε : ℝ
pos : 0 < ε
restrict_on_K : C(X, ℝ) →⋆ₐ[ℝ] C(↑K, ℝ) := compStarAlgHom' ℝ ℝ { toFun := Subtype.val, continuous_toFun := ⋯ }
AK : Subalgebra ℝ C(↑K, ℝ) := Subalgebra.map (↑restrict_on_K) A
x y : ↑K
hxy : x ≠ y
⊢ ∃ f ∈ (fun f ↦ ⇑f) '' ↑AK, f x ≠ f y

Tactic:
obtain ⟨_, ⟨g, hg1, hg2⟩, hg_sep⟩ := hA (Subtype.coe_ne_coe.mpr hxy)

Goal state after:
X : Type u_2
inst✝ : TopologicalSpace X
A : Subalgebra ℝ C(X, ℝ)
hA : A.SeparatesPoints
f : C(X, ℝ)
K : Set X
hK : IsCompact K
ε : ℝ
pos : 0 < ε
restrict_on_K : C(X, ℝ) →⋆ₐ[ℝ] C(↑K, ℝ) := compStarAlgHom' ℝ ℝ { toFun := Subtype.val, continuous_toFun := ⋯ }
AK : Subalgebra ℝ C(↑K, ℝ) := Subalgebra.map (↑restrict_on_K) A
x y : ↑K
hxy : x ≠ y
w✝ : X → ℝ
hg_sep : w✝ ↑x ≠ w✝ ↑y
g : C(X, ℝ)
hg1 : g ∈ ↑A
hg2 : (fun f ↦ ⇑f) g = w✝
⊢ ∃ f ∈ (fun f ↦ ⇑f) '' ↑AK, f x ≠ f y
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Unique

Goal state before:
pp: F : Type u_1
R : Type u_2
S : Type u_3
A : Type u_4
B : Type u_5
p : A → Prop
q : B → Prop
inst✝²⁹ : CommSemiring R
inst✝²⁸ : Nontrivial R
inst✝²⁷ : StarRing R
inst✝²⁶ : MetricSpace R
inst✝²⁵ : IsTopologicalSemiring R
inst✝²⁴ : ContinuousStar R
inst✝²³ : CommRing S
inst✝²² : Algebra R S
inst✝²¹ : NonUnitalRing A
inst✝²⁰ : StarRing A
inst✝¹⁹ : TopologicalSpace A
inst✝¹⁸ : Module R A
inst✝¹⁷ : IsScalarTower R A A
inst✝¹⁶ : SMulCommClass R A A
inst✝¹⁵ : NonUnitalRing B
inst✝¹⁴ : StarRing B
inst✝¹³ : TopologicalSpace B
inst✝¹² : Module R B
inst✝¹¹ : IsScalarTower R B B
inst✝¹⁰ : SMulCommClass R B B
inst✝⁹ : Module S A
inst✝⁸ : Module S B
inst✝⁷ : IsScalarTower R S A
inst✝⁶ : IsScalarTower R S B
inst✝⁵ : NonUnitalContinuousFunctionalCalculus R A p
inst✝⁴ : NonUnitalContinuousFunctionalCalculus R B q
inst✝³ : ContinuousMapZero.UniqueHom R B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F S A B
inst✝ : StarHomClass F A B
φ : F
f : R → R
a : A
hf : ContinuousOn f (quasispectrum R a)
hf₀ : f 0 = 0
hφ : Continuous[inst✝¹⁹, inst✝¹³] ⇑φ
ha : p a
hφa : q (φ a)
ψ : A →⋆ₙₐ[R] B := ⋯
this : Continuous[inst✝¹⁹, inst✝¹³] ⇑ψ
h_spec : quasispectrum R (φ a) ⊆ quasispectrum R a
hψa : q (ψ a)
ι : C(↑(quasispectrum R (ψ a)), ↑(quasispectrum R a))₀ := ⋯
⊢ (ψ.comp (cfcₙHom ha)) (ContinuousMapZero.id (quasispectrum R a)) =
    (cfcₙHom hψa) (ContinuousMapZero.id (quasispectrum R (ψ a)))

Tactic:
simp [cfcₙHom_id]

Goal state after:
Module: Mathlib.Topology.Semicontinuity.Hemicontinuity

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝² : TopologicalSpace α
f : α → Set β
s : Set α
ι : Type u_3
F : ι → α → Set β
l : Filter ι
inst✝¹ : l.NeBot
inst✝ : UniformSpace β
htendsto : TendstoUniformlyOn F f l s
hF : ∀ (n : ι), LowerHemicontinuousOn (F n) s
x₀ : α
hx₀s : x₀ ∈ s
V : Set β
hV : IsOpen[inst✝.toTopologicalSpace] V
⊢ (f x₀ ∩ V).Nonempty → ∀ᶠ (x' : α) in 𝓝[s] x₀, (f x' ∩ V).Nonempty

Tactic:
⟨y₀, hy₀f, hy₀V⟩

Goal state after:
α : Type u_1
β : Type u_2
inst✝² : TopologicalSpace α
f : α → Set β
s : Set α
ι : Type u_3
F : ι → α → Set β
l : Filter ι
inst✝¹ : l.NeBot
inst✝ : UniformSpace β
htendsto : TendstoUniformlyOn F f l s
hF : ∀ (n : ι), LowerHemicontinuousOn (F n) s
x₀ : α
hx₀s : x₀ ∈ s
V : Set β
hV : IsOpen[inst✝.toTopologicalSpace] V
y₀ : β
hy₀f : y₀ ∈ f x₀
hy₀V : y₀ ∈ V
⊢ ∀ᶠ (x' : α) in 𝓝[s] x₀, (f x' ∩ V).Nonempty
Module: Mathlib.Analysis.Normed.Algebra.Spectrum

Goal state before:
pp: 𝕜 : Type u_1
A : Type u_2
inst✝³ : NormedField 𝕜
inst✝² : NormedRing A
inst✝¹ : NormedAlgebra 𝕜 A
inst✝ : CompleteSpace A
a : A
k : 𝕜
h : ‖a‖ * ‖1‖ < ‖k‖
⊢ k ∈ ρ a

Tactic:
rw [resolventSet, Set.mem_ofPred_eq, Algebra.algebraMap_eq_smul_one]

Goal state after:
𝕜 : Type u_1
A : Type u_2
inst✝³ : NormedField 𝕜
inst✝² : NormedRing A
inst✝¹ : NormedAlgebra 𝕜 A
inst✝ : CompleteSpace A
a : A
k : 𝕜
h : ‖a‖ * ‖1‖ < ‖k‖
⊢ IsUnit (k • 1 - a)
Module: Mathlib.Topology.Sets.VietorisTopology

Goal state before:
pp: case inr
α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
inst✝ : TopologicalSpace β
f : α → Set β
x✝ :
  (∀ (U : Set β), IsOpen[inst✝] U → IsOpen[inst✝¹] (f ⁻¹' 𝒫 U)) ∧
    ∀ (F : Set β), IsClosed[inst✝] F → IsClosed[inst✝¹] (f ⁻¹' 𝒫 F)
h₁ : ∀ (U : Set β), IsOpen[inst✝] U → IsOpen[inst✝¹] (f ⁻¹' 𝒫 U)
h₂ : ∀ (F : Set β), IsClosed[inst✝] F → IsClosed[inst✝¹] (f ⁻¹' 𝒫 F)
U : Set β
hU : U ∈ {V | IsOpen[inst✝] V}
⊢ IsOpen[inst✝¹] (f ⁻¹' (fun V ↦ {s | (s ∩ V).Nonempty}) U)

Tactic:
simp_rw [preimage_ofPred_eq, ← not_disjoint_iff_nonempty_inter, ← compl_ofPred,
      isOpen_compl_iff, ← subset_compl_iff_disjoint_right]

Goal state after:
case inr
α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
inst✝ : TopologicalSpace β
f : α → Set β
x✝ :
  (∀ (U : Set β), IsOpen[inst✝] U → IsOpen[inst✝¹] (f ⁻¹' 𝒫 U)) ∧
    ∀ (F : Set β), IsClosed[inst✝] F → IsClosed[inst✝¹] (f ⁻¹' 𝒫 F)
h₁ : ∀ (U : Set β), IsOpen[inst✝] U → IsOpen[inst✝¹] (f ⁻¹' 𝒫 U)
h₂ : ∀ (F : Set β), IsClosed[inst✝] F → IsClosed[inst✝¹] (f ⁻¹' 𝒫 F)
U : Set β
hU : U ∈ {V | IsOpen[inst✝] V}
⊢ IsClosed[inst✝¹] {a | f a ⊆ Uᶜ}
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Instances

Goal state before:
pp: case refine_1
𝕜 : Type u_1
A : Type u_2
inst✝⁸ : RCLike 𝕜
inst✝⁷ : NonUnitalNormedRing A
inst✝⁶ : StarRing A
inst✝⁵ : NormedSpace 𝕜 A
inst✝⁴ : IsScalarTower 𝕜 A A
inst✝³ : SMulCommClass 𝕜 A A
inst✝² : StarModule 𝕜 A
p : A → Prop
p₁ : Unitization 𝕜 A → Prop
hp₁ : ∀ {x : A}, p₁ ↑x ↔ p x
a : A
ha : p a
inst✝¹ : ClosedEmbeddingContinuousFunctionalCalculus 𝕜 (Unitization 𝕜 A) p₁
inst✝ : CompleteSpace A
f : C(↑(σₙ 𝕜 a), 𝕜)₀
h₁ :
  (cfcₙAux ⋯ a ha) f ∈
    closure[Unitization.instUniformSpace.toTopologicalSpace]
      (⇑(cfcₙAux ⋯ a ha) '' ↑(NonUnitalStarAlgebra.adjoin 𝕜 {ContinuousMapZero.id (σₙ 𝕜 a)}))
⊢ ↑(NonUnitalStarSubalgebra.map (cfcₙAux ⋯ a ha) (NonUnitalStarAlgebra.adjoin 𝕜 {ContinuousMapZero.id (σₙ 𝕜 a)})) ⊆
    ↑(NonUnitalStarAlgHom.range (Unitization.inrNonUnitalStarAlgHom 𝕜 A))

Tactic:
SetLike.coe_subset_coe,

Goal state after:
case refine_1
𝕜 : Type u_1
A : Type u_2
inst✝⁸ : RCLike 𝕜
inst✝⁷ : NonUnitalNormedRing A
inst✝⁶ : StarRing A
inst✝⁵ : NormedSpace 𝕜 A
inst✝⁴ : IsScalarTower 𝕜 A A
inst✝³ : SMulCommClass 𝕜 A A
inst✝² : StarModule 𝕜 A
p : A → Prop
p₁ : Unitization 𝕜 A → Prop
hp₁ : ∀ {x : A}, p₁ ↑x ↔ p x
a : A
ha : p a
inst✝¹ : ClosedEmbeddingContinuousFunctionalCalculus 𝕜 (Unitization 𝕜 A) p₁
inst✝ : CompleteSpace A
f : C(↑(σₙ 𝕜 a), 𝕜)₀
h₁ :
  (cfcₙAux ⋯ a ha) f ∈
    closure[Unitization.instUniformSpace.toTopologicalSpace]
      (⇑(cfcₙAux ⋯ a ha) '' ↑(NonUnitalStarAlgebra.adjoin 𝕜 {ContinuousMapZero.id (σₙ 𝕜 a)}))
⊢ NonUnitalStarSubalgebra.map (cfcₙAux ⋯ a ha) (NonUnitalStarAlgebra.adjoin 𝕜 {ContinuousMapZero.id (σₙ 𝕜 a)}) ≤
    NonUnitalStarAlgHom.range (Unitization.inrNonUnitalStarAlgHom 𝕜 A)
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Isometric

Goal state before:
pp: case a
𝕜 : Type u_1
A : Type u_2
p : A → Prop
inst✝⁶ : RCLike 𝕜
inst✝⁵ : NonUnitalNormedRing A
inst✝⁴ : StarRing A
inst✝³ : NormedSpace 𝕜 A
inst✝² : IsScalarTower 𝕜 A A
inst✝¹ : SMulCommClass 𝕜 A A
inst✝ : NonUnitalIsometricContinuousFunctionalCalculus 𝕜 A p
f : 𝕜 → 𝕜
a : A
hf : ContinuousOn f (σₙ 𝕜 a)
hf₀ : f 0 = 0
ha : p a
x : 𝕜
hx' : x ∈ σₙ 𝕜 a
hx : IsGreatest ((fun x ↦ ‖f x‖) '' σₙ 𝕜 a) ((fun x ↦ ‖f x‖) x)
⊢ (fun x ↦ ‖f x‖) x ≤ ‖{ toFun := (σₙ 𝕜 a).domRestrict f, continuous_toFun := ⋯, map_zero' := ⋯ }‖

Tactic:
· exact le_trans (by simp) <| ContinuousMap.norm_coe_le_norm _ (⟨x, hx'⟩ : σₙ 𝕜 a)

Goal state after:
Module: Mathlib.Analysis.Normed.Algebra.Spectrum

Goal state before:
pp: 𝕜 : Type u_1
A : Type u_2
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : ProperSpace 𝕜
inst✝⁴ : NonUnitalNormedRing A
inst✝³ : NormedSpace 𝕜 A
inst✝² : SMulCommClass 𝕜 A A
inst✝¹ : IsScalarTower 𝕜 A A
inst✝ : CompleteSpace A
a : A
⊢ spectrum 𝕜 ↑a = (spectrum 𝕜 ∘ fun x ↦ toLp 1 ↑x) a

Tactic:
← AlgEquiv.spectrum_eq (unitizationAlgEquiv 𝕜 (𝕜 := 𝕜) (A := A) |>.symm)

Goal state after:
𝕜 : Type u_1
A : Type u_2
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : ProperSpace 𝕜
inst✝⁴ : NonUnitalNormedRing A
inst✝³ : NormedSpace 𝕜 A
inst✝² : SMulCommClass 𝕜 A A
inst✝¹ : IsScalarTower 𝕜 A A
inst✝ : CompleteSpace A
a : A
⊢ spectrum 𝕜 ((unitizationAlgEquiv 𝕜).symm ↑a) = (spectrum 𝕜 ∘ fun x ↦ toLp 1 ↑x) a
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: case upper
A : Type u_1
inst✝ : CStarAlgebra A
a : A
ha : IsSelfAdjoint a
⊢ IsConnected ((σ ℂ a)ᶜ ∩ {z | 0 ≤ z.im})

Tactic:
case' =>

Goal state after:
A : Type u_1
inst✝ : CStarAlgebra A
a : A
ha : IsSelfAdjoint a
⊢ {z | 0 < z.im} ⊆ (σ ℂ a)ᶜ ∩ {z | 0 ≤ z.im}
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: case lower
A : Type u_1
inst✝ : CStarAlgebra A
a : A
ha : IsSelfAdjoint a
⊢ IsConnected ((σ ℂ a)ᶜ ∩ {z | z.im ≤ 0})

Tactic:
case' =>

Goal state after:
A : Type u_1
inst✝ : CStarAlgebra A
a : A
ha : IsSelfAdjoint a
⊢ {z | z.im < 0} ⊆ (σ ℂ a)ᶜ ∩ {z | z.im ≤ 0}
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: F : Type u_1
A : Type u_2
B : Type u_3
inst✝⁴ : NonUnitalCStarAlgebra A
inst✝³ : NonUnitalCStarAlgebra B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F ℂ A B
inst✝ : StarHomClass F A B
φ : F
a : A
ψ : Unitization ℂ A →⋆ₐ[ℂ] Unitization ℂ B
x : Unitization ℂ A
this : ∀ {s : Unitization ℂ A}, IsSelfAdjoint s → ‖ψ s‖₊ ≤ ‖s‖₊
⊢ ‖ψ x‖₊ ≤ ‖x‖₊

Tactic:
refine nonneg_le_nonneg_of_sq_le_sq zero_le ?_

Goal state after:
F : Type u_1
A : Type u_2
B : Type u_3
inst✝⁴ : NonUnitalCStarAlgebra A
inst✝³ : NonUnitalCStarAlgebra B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F ℂ A B
inst✝ : StarHomClass F A B
φ : F
a : A
ψ : Unitization ℂ A →⋆ₐ[ℂ] Unitization ℂ B
x : Unitization ℂ A
this : ∀ {s : Unitization ℂ A}, IsSelfAdjoint s → ‖ψ s‖₊ ≤ ‖s‖₊
⊢ ‖ψ x‖₊ * ‖ψ x‖₊ ≤ ‖x‖₊ * ‖x‖₊
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: F : Type u_1
A : Type u_2
B : Type u_3
inst✝⁴ : NonUnitalCStarAlgebra A
inst✝³ : NonUnitalCStarAlgebra B
inst✝² : FunLike F A B
inst✝¹ : NonUnitalAlgHomClass F ℂ A B
inst✝ : StarHomClass F A B
φ : F
a : A
ψ : Unitization ℂ A →⋆ₐ[ℂ] Unitization ℂ B
x : Unitization ℂ A
this : ∀ {s : Unitization ℂ A}, IsSelfAdjoint s → ‖ψ s‖₊ ≤ ‖s‖₊
⊢ ‖ψ x‖₊ ≤ ‖x‖₊

Tactic:
by
      refine nonneg_le_nonneg_of_sq_le_sq zero_le ?_
      simp_rw [← nnnorm_star_mul_self, ← map_star, ← map_mul]
      exact this <| .star_mul_self x

Goal state after:
Module: Mathlib.Topology.ContinuousMap.ZeroAtInfty

Goal state before:
pp: F : Type u_1
α : Type u
β : Type v
γ : Type w
inst✝⁴ : TopologicalSpace α
inst✝³ : TopologicalSpace β
inst✝² : Zero β
inst✝¹ : FunLike F α β
inst✝ : ZeroAtInftyContinuousMapClass F α β
f : α →C₀ β
f' : α → β
h : f' = ⇑f
⊢ Tendsto f' (cocompact α) (𝓝 0)

Tactic:
simp_rw [h]
    exact f.zero_at_infty'

Goal state after:
Module: Mathlib.Topology.ContinuousMap.ZeroAtInfty

Goal state before:
pp: F : Type u_1
α : Type u
β : Type v
γ : Type w
inst✝⁷ : TopologicalSpace α
inst✝⁶ : TopologicalSpace β
x : α
R : Type u_2
inst✝⁵ : Semiring R
inst✝⁴ : NonUnitalNonAssocSemiring β
inst✝³ : IsTopologicalSemiring β
inst✝² : Module R β
inst✝¹ : ContinuousConstSMul R β
inst✝ : SMulCommClass R β β
r : R
f g : α →C₀ β
⊢ r • f • g = f • r • g

Tactic:
ext
    simp only [smul_eq_mul, coe_smul, coe_mul, Pi.smul_apply, Pi.mul_apply]
    rw [← smul_eq_mul, ← smul_eq_mul, smul_comm]

Goal state after:
Module: Mathlib.Topology.ContinuousMap.ZeroAtInfty

Goal state before:
pp: α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : PseudoMetricSpace β
inst✝ : Zero β
⊢ IsClosed (range toBCF)

Tactic:
by
  refine isClosed_iff_clusterPt.mpr fun f hf => ?_
  rw [clusterPt_principal_iff] at hf
  have : Tendsto f (cocompact α) (𝓝 0) := by
    refine Metric.tendsto_nhds.mpr fun ε hε => ?_
    obtain ⟨_, hg, g, rfl⟩ := hf (ball f (ε / 2)) (ball_mem_nhds f <| half_pos hε)
    refine (Metric.tendsto_nhds.mp (zero_at_infty g) (ε / 2) (half_pos hε)).mp
      (Eventually.of_forall fun x hx => ?_)
    calc
      dist (f x) 0 ≤ dist (g.toBCF x) (f x) + dist (g x) 0 := dist_triangle_left _ _ _
      _ < dist g.toBCF f + ε / 2 := add_lt_add_of_le_of_lt (dist_coe_le_dist x) hx
      _ ≤ ε := by grw [mem_ball.1 hg, add_halves ε]
  exact ⟨⟨f.toContinuousMap, this⟩, rfl⟩

Goal state after:
Module: Mathlib.Topology.Sets.VietorisTopology

Goal state before:
pp: case a
α : Type u_1
β : Type u_2
γ : Type u_3
inst✝³ : TopologicalSpace α
inst✝² : TopologicalSpace β
inst✝¹ : TopologicalSpace γ
f : α → β
inst✝ : LocallyConnectedSpace α
basis :
  IsTopologicalBasis
    ((fun u ↦ {K | ↑K ⊆ ⋃₀ u ∧ ∀ U ∈ u, (↑K ∩ U).Nonempty}) ''
      {u | u.Finite ∧ u ⊆ {s | IsOpen[inst✝³] s ∧ IsPreconnected s}})
u : Set (Set α)
hu' : u.Finite
hu : u ⊆ {s | IsOpen[inst✝³] s ∧ IsPreconnected s}
this : Fintype ↑u := hu'.fintype
⊢ (univ.pi fun U ↦ {K | (↑K).Nonempty ∧ (↑K).Finite ∧ ↑K ⊆ ↑U}) ⊆
    {a |
      (Finset.univ.sup fun i ↦ ↑(a i)) ⊆ ⋃₀ u ∧
        (∀ U ∈ u, ((Finset.univ.sup fun i ↦ ↑(a i)) ∩ U).Nonempty) ∧ (Finset.univ.sup fun i ↦ ↑(a i)).Finite}

Tactic:
Finset.sup_eq_iSup,

Goal state after:
case a
α : Type u_1
β : Type u_2
γ : Type u_3
inst✝³ : TopologicalSpace α
inst✝² : TopologicalSpace β
inst✝¹ : TopologicalSpace γ
f : α → β
inst✝ : LocallyConnectedSpace α
basis :
  IsTopologicalBasis
    ((fun u ↦ {K | ↑K ⊆ ⋃₀ u ∧ ∀ U ∈ u, (↑K ∩ U).Nonempty}) ''
      {u | u.Finite ∧ u ⊆ {s | IsOpen[inst✝³] s ∧ IsPreconnected s}})
u : Set (Set α)
hu' : u.Finite
hu : u ⊆ {s | IsOpen[inst✝³] s ∧ IsPreconnected s}
this : Fintype ↑u := hu'.fintype
⊢ (univ.pi fun U ↦ {K | (↑K).Nonempty ∧ (↑K).Finite ∧ ↑K ⊆ ↑U}) ⊆
    {a |
      ⨆ a_1 ∈ Finset.univ, ↑(a a_1) ⊆ ⋃₀ u ∧
        (∀ U ∈ u, ((⨆ a_2 ∈ Finset.univ, ↑(a a_2)) ∩ U).Nonempty) ∧ (⨆ a_1 ∈ Finset.univ, ↑(a a_1)).Finite}
Module: Mathlib.Analysis.LocallyConvex.HahnBanach

Goal state before:
pp: case refine_1
𝕜 : Type u_1
E : Type u_2
inst✝³ : AddCommGroup E
inst✝² : NormedField 𝕜
inst✝¹ : IsRCLikeNormedField 𝕜
inst✝ : Module 𝕜 E
S : Submodule 𝕜 E
f : Dual 𝕜 ↥S
p : Seminorm 𝕜 E
hp : ∀ (x : ↥S), ‖f x‖ ≤ p ↑x
this✝¹ : RCLike 𝕜 := IsRCLikeNormedField.rclike 𝕜
this✝ : Module ℝ E := restrictScalars ℝ 𝕜 E
this : IsScalarTower ℝ 𝕜 E := IsScalarTower.restrictScalars ℝ 𝕜 E
fr : Dual ℝ ↥S := reLm ∘ₗ ↑ℝ f
g : Dual ℝ E
hg : ∀ (x : ↥S), g ↑x = fr x
hgp : ∀ (x : E), |g x| ≤ (Seminorm.restrictScalars ℝ p) x
x : ↥S
⊢ g.extendRCLike ↑x = f x

pp: case refine_2
𝕜 : Type u_1
E : Type u_2
inst✝³ : AddCommGroup E
inst✝² : NormedField 𝕜
inst✝¹ : IsRCLikeNormedField 𝕜
inst✝ : Module 𝕜 E
S : Submodule 𝕜 E
f : Dual 𝕜 ↥S
p : Seminorm 𝕜 E
hp : ∀ (x : ↥S), ‖f x‖ ≤ p ↑x
this✝¹ : RCLike 𝕜 := IsRCLikeNormedField.rclike 𝕜
this✝ : Module ℝ E := restrictScalars ℝ 𝕜 E
this : IsScalarTower ℝ 𝕜 E := IsScalarTower.restrictScalars ℝ 𝕜 E
fr : Dual ℝ ↥S := reLm ∘ₗ ↑ℝ f
g : Dual ℝ E
hg : ∀ (x : ↥S), g ↑x = fr x
hgp : ∀ (x : E), |g x| ≤ (Seminorm.restrictScalars ℝ p) x
x : E
⊢ ‖g.extendRCLike x‖ ≤ p x

Tactic:
· rw [g.extendRCLike_apply, ← Submodule.coe_smul, hg, hg]
    simp [fr, mul_comm I]

Goal state after:
case refine_2
𝕜 : Type u_1
E : Type u_2
inst✝³ : AddCommGroup E
inst✝² : NormedField 𝕜
inst✝¹ : IsRCLikeNormedField 𝕜
inst✝ : Module 𝕜 E
S : Submodule 𝕜 E
f : Dual 𝕜 ↥S
p : Seminorm 𝕜 E
hp : ∀ (x : ↥S), ‖f x‖ ≤ p ↑x
this✝¹ : RCLike 𝕜 := IsRCLikeNormedField.rclike 𝕜
this✝ : Module ℝ E := restrictScalars ℝ 𝕜 E
this : IsScalarTower ℝ 𝕜 E := IsScalarTower.restrictScalars ℝ 𝕜 E
fr : Dual ℝ ↥S := reLm ∘ₗ ↑ℝ f
g : Dual ℝ E
hg : ∀ (x : ↥S), g ↑x = fr x
hgp : ∀ (x : E), |g x| ≤ (Seminorm.restrictScalars ℝ p) x
x : E
⊢ ‖g.extendRCLike x‖ ≤ p x
Module: Mathlib.Analysis.LocallyConvex.HahnBanach

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁹ : NormedField 𝕜
inst✝⁸ : IsRCLikeNormedField 𝕜
F : Type u_3
inst✝⁷ : AddCommGroup F
inst✝⁶ : TopologicalSpace F
inst✝⁵ : IsTopologicalAddGroup F
inst✝⁴ : Module 𝕜 F
inst✝³ : ContinuousSMul 𝕜 F
inst✝² : T2Space F
inst✝¹ : PolynormableSpace 𝕜 F
S : Submodule 𝕜 F
inst✝ : FiniteDimensional 𝕜 ↥S
⊢ S.ClosedComplemented

Tactic:
let ⟨g, hg⟩ := (ContinuousLinearMap.id 𝕜 S).exist_extension_of_finiteDimensional_range
  exact ⟨g, DFunLike.congr_fun hg.symm⟩

Goal state after:
Module: Mathlib.Analysis.Normed.Module.Dual

Goal state before:
pp: 𝕜 : Type u_1
inst✝² : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹ : SeminormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
s : Set E
x' : StrongDual 𝕜 E
c : 𝕜
hc : ∀ z ∈ s, ‖x' z‖ ≤ ‖c‖
c_zero : ¬c = 0
eq : ∀ (z : E), ‖c⁻¹ • x' z‖ = ‖c⁻¹‖ * ‖x' z‖
z : E
hzs : z ∈ s
⊢ ‖c⁻¹‖ * ‖x' z‖ ≤ ‖c⁻¹‖ * ‖c‖

Tactic:
apply mul_le_mul (le_of_eq rfl) (hc z hzs) (norm_nonneg _) (norm_nonneg _)

Goal state after:
Module: Mathlib.Analysis.Normed.Affine.AddTorsor

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁴ : SeminormedAddCommGroup V
inst✝³ : PseudoMetricSpace P
inst✝² : NormedAddTorsor V P
𝕜 : Type u_5
inst✝¹ : NormedField 𝕜
inst✝ : NormedSpace 𝕜 V
p₁ p₂ : P
c : 𝕜
⊢ dist ((homothety p₁ c) p₂) p₂ = ‖1 - c‖ * dist p₁ p₂

Tactic:
dist_homothety_self

Goal state after:
V : Type u_1
P : Type u_2
inst✝⁴ : SeminormedAddCommGroup V
inst✝³ : PseudoMetricSpace P
inst✝² : NormedAddTorsor V P
𝕜 : Type u_5
inst✝¹ : NormedField 𝕜
inst✝ : NormedSpace 𝕜 V
p₁ p₂ : P
c : 𝕜
⊢ ‖1 - c‖ * dist p₁ p₂ = ‖1 - c‖ * dist p₁ p₂
Module: Mathlib.Analysis.Normed.Module.WeakDual

Goal state before:
pp: case h.left
𝕜 : Type u_1
E : Type u_3
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : SeminormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : SeparableSpace E
⊢ ∀ (n : ℕ), Continuous[_, PseudoMetricSpace.toUniformSpace.toTopologicalSpace] fun φ ↦ φ (denseSeq E n)

pp: case h.right
𝕜 : Type u_1
E : Type u_3
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : SeminormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : SeparableSpace E
⊢ ∀ ⦃x y : WeakDual 𝕜 E⦄, x ≠ y → ∃ n, x (denseSeq E n) ≠ y (denseSeq E n)

Tactic:
· exact fun _ ↦ eval_continuous _

Goal state after:
case h.right
𝕜 : Type u_1
E : Type u_3
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : SeminormedAddCommGroup E
inst✝¹ : NormedSpace 𝕜 E
inst✝ : SeparableSpace E
⊢ ∀ ⦃x y : WeakDual 𝕜 E⦄, x ≠ y → ∃ n, x (denseSeq E n) ≠ y (denseSeq E n)
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
h0 : 0 < 2⁻¹
h1234 : 2⁻¹ < 3 / 4
h1 : 3 / 4 < 1
x : X
x✝ : True
n : ℕ
ihn : ∀ (c : CU P), ∀ᶠ (x_1 : X) in 𝓝 x, dist (c.lim x_1) (c.lim x) ≤ (3 / 4) ^ n
c : CU P
hxl : x ∈ c.left.U
a✝ : X
hyl : a✝ ∈ c.left.U
hyd : dist (c.left.lim a✝) (c.left.lim x) ≤ (3 / 4) ^ n
⊢ (dist (c.left.lim a✝) (c.left.lim x) + dist 0 0) / 2 ≤ 3 / 4 * (3 / 4) ^ n

Tactic:
dist_self,

Goal state after:
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
h0 : 0 < 2⁻¹
h1234 : 2⁻¹ < 3 / 4
h1 : 3 / 4 < 1
x : X
x✝ : True
n : ℕ
ihn : ∀ (c : CU P), ∀ᶠ (x_1 : X) in 𝓝 x, dist (c.lim x_1) (c.lim x) ≤ (3 / 4) ^ n
c : CU P
hxl : x ∈ c.left.U
a✝ : X
hyl : a✝ ∈ c.left.U
hyd : dist (c.left.lim a✝) (c.left.lim x) ≤ (3 / 4) ^ n
⊢ (dist (c.left.lim a✝) (c.left.lim x) + 0) / 2 ≤ 3 / 4 * (3 / 4) ^ n
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
h0 : 0 < 2⁻¹
h1234 : 2⁻¹ < 3 / 4
h1 : 3 / 4 < 1
x : X
x✝ : True
n : ℕ
ihn : ∀ (c : CU P), ∀ᶠ (x_1 : X) in 𝓝 x, dist (c.lim x_1) (c.lim x) ≤ (3 / 4) ^ n
c : CU P
y : X
hydl : dist (c.left.right.lim y) (c.left.right.lim x) ≤ (3 / 4) ^ n
hydr : dist (c.right.lim y) (c.right.lim x) ≤ (3 / 4) ^ n
hxl : x ∉ c.left.left.U
hyl : y ∉ c.left.left.U
⊢ ((dist 1 1 + dist (c.left.right.lim y) (c.left.right.lim x)) / 2 + dist (c.right.lim y) (c.right.lim x)) / 2 ≤
    (3 / 4) ^ n * (3 / 4)

Tactic:
dist_self,

Goal state after:
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
h0 : 0 < 2⁻¹
h1234 : 2⁻¹ < 3 / 4
h1 : 3 / 4 < 1
x : X
x✝ : True
n : ℕ
ihn : ∀ (c : CU P), ∀ᶠ (x_1 : X) in 𝓝 x, dist (c.lim x_1) (c.lim x) ≤ (3 / 4) ^ n
c : CU P
y : X
hydl : dist (c.left.right.lim y) (c.left.right.lim x) ≤ (3 / 4) ^ n
hydr : dist (c.right.lim y) (c.right.lim x) ≤ (3 / 4) ^ n
hxl : x ∉ c.left.left.U
hyl : y ∉ c.left.left.U
⊢ ((0 + dist (c.left.right.lim y) (c.left.right.lim x)) / 2 + dist (c.right.lim y) (c.right.lim x)) / 2 ≤
    (3 / 4) ^ n * (3 / 4)
Module: Mathlib.Analysis.SpecialFunctions.ContinuousFunctionalCalculus.PosPart.Basic

Goal state before:
pp: A : Type u_1
inst✝⁶ : NonUnitalRing A
inst✝⁵ : Module ℝ A
inst✝⁴ : SMulCommClass ℝ A A
inst✝³ : IsScalarTower ℝ A A
inst✝² : StarRing A
inst✝¹ : TopologicalSpace A
inst✝ : NonUnitalContinuousFunctionalCalculus ℝ A IsSelfAdjoint
a : A
ha : IsSelfAdjoint a
⊢ cfcₙ (fun x ↦ x⁺) a - cfcₙ (fun x ↦ x⁻) a = a

Tactic:
← cfcₙ_sub _ _

Goal state after:
A : Type u_1
inst✝⁶ : NonUnitalRing A
inst✝⁵ : Module ℝ A
inst✝⁴ : SMulCommClass ℝ A A
inst✝³ : IsScalarTower ℝ A A
inst✝² : StarRing A
inst✝¹ : TopologicalSpace A
inst✝ : NonUnitalContinuousFunctionalCalculus ℝ A IsSelfAdjoint
a : A
ha : IsSelfAdjoint a
⊢ cfcₙ (fun x ↦ x⁺ - x⁻) a = a