mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Topology.ContinuousMap.StoneWeierstrass

Goal state before:
pp: case pos
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : CompactSpace X
L : Set C(X, ℝ)
nA : L.Nonempty
inf_mem : ∀ f ∈ L, ∀ g ∈ L, f ⊓ g ∈ L
sup_mem : ∀ f ∈ L, ∀ g ∈ L, f ⊔ g ∈ L
sep : ∀ (v : X → ℝ) (x y : X), ∃ f ∈ L, f x = v x ∧ f y = v y
f : C(X, ℝ)
ε : ℝ
pos : 0 < ε
nX : Nonempty X
g : X → X → C(X, ℝ)
hg : ∀ (x y : X), g x y ∈ L
w₁ : ∀ (x y : X), (g x y) x = f x
w₂ : ∀ (x y : X), (g x y) y = f y
U : X → X → Set X := fun x y ↦ {z | f z - ε < (g x y) z}
U_nhds_y : ∀ (x y : X), U x y ∈ 𝓝 y
ys : X → Finset X := fun x ↦ ⋯.choose
ys_w : ∀ (x : X), ⋃ y ∈ ys x, U x y = ⊤ :=
  fun x ↦ Exists.choose_spec (CompactSpace.elim_nhds_subcover (U x) (U_nhds_y x))
ys_nonempty : ∀ (x : X), (ys x).Nonempty
h : X → ↑L := fun x ↦ ⟨(ys x).sup' ⋯ fun y ↦ g x y, ⋯⟩
lt_h : ∀ (x z : X), f z - ε < ↑(h x) z
⊢ ∃ x, dist x f < ε ∧ x ∈ L

Tactic:
have h_eq : ∀ x, (h x : X → ℝ) x = f x := by intro x; simp [h, w₁]

Goal state after:
case pos
X : Type u_1
inst✝¹ : TopologicalSpace X
inst✝ : CompactSpace X
L : Set C(X, ℝ)
nA : L.Nonempty
inf_mem : ∀ f ∈ L, ∀ g ∈ L, f ⊓ g ∈ L
sup_mem : ∀ f ∈ L, ∀ g ∈ L, f ⊔ g ∈ L
sep : ∀ (v : X → ℝ) (x y : X), ∃ f ∈ L, f x = v x ∧ f y = v y
f : C(X, ℝ)
ε : ℝ
pos : 0 < ε
nX : Nonempty X
g : X → X → C(X, ℝ)
hg : ∀ (x y : X), g x y ∈ L
w₁ : ∀ (x y : X), (g x y) x = f x
w₂ : ∀ (x y : X), (g x y) y = f y
U : X → X → Set X := fun x y ↦ {z | f z - ε < (g x y) z}
U_nhds_y : ∀ (x y : X), U x y ∈ 𝓝 y
ys : X → Finset X := fun x ↦ ⋯.choose
ys_w : ∀ (x : X), ⋃ y ∈ ys x, U x y = ⊤ :=
  fun x ↦ Exists.choose_spec (CompactSpace.elim_nhds_subcover (U x) (U_nhds_y x))
ys_nonempty : ∀ (x : X), (ys x).Nonempty
h : X → ↑L := fun x ↦ ⟨(ys x).sup' ⋯ fun y ↦ g x y, ⋯⟩
lt_h : ∀ (x z : X), f z - ε < ↑(h x) z
h_eq : ∀ (x : X), ↑(h x) x = f x
⊢ ∃ x, dist x f < ε ∧ x ∈ L
Module: Mathlib.Analysis.Normed.Algebra.Unitization

Goal state before:
pp: 𝕜 : Type u_1
A : Type u_2
inst✝⁵ : NontriviallyNormedField 𝕜
inst✝⁴ : NonUnitalNormedRing A
inst✝³ : NormedSpace 𝕜 A
inst✝² : IsScalarTower 𝕜 A A
inst✝¹ : SMulCommClass 𝕜 A A
inst✝ : RegularNormedAlgebra 𝕜 A
x : Unitization 𝕜 A
a✝ : Nontrivial A
⊢ ‖((addEquiv 𝕜 A) x).2‖ ≤ 2 * max ‖x.toProd.1‖ ‖(algebraMap 𝕜 (A →L[𝕜] A)) x.toProd.1 + (mul 𝕜 A) x.toProd.2‖

Tactic:
two_mul

Goal state after:
𝕜 : Type u_1
A : Type u_2
inst✝⁵ : NontriviallyNormedField 𝕜
inst✝⁴ : NonUnitalNormedRing A
inst✝³ : NormedSpace 𝕜 A
inst✝² : IsScalarTower 𝕜 A A
inst✝¹ : SMulCommClass 𝕜 A A
inst✝ : RegularNormedAlgebra 𝕜 A
x : Unitization 𝕜 A
a✝ : Nontrivial A
⊢ ‖((addEquiv 𝕜 A) x).2‖ ≤
    max ‖x.toProd.1‖ ‖(algebraMap 𝕜 (A →L[𝕜] A)) x.toProd.1 + (mul 𝕜 A) x.toProd.2‖ +
      max ‖x.toProd.1‖ ‖(algebraMap 𝕜 (A →L[𝕜] A)) x.toProd.1 + (mul 𝕜 A) x.toProd.2‖
Module: Mathlib.Analysis.CStarAlgebra.Unitization

Goal state before:
pp: case refine_1
𝕜 : Type u_1
E : Type u_2
inst✝⁶ : DenselyNormedField 𝕜
inst✝⁵ : NonUnitalNormedRing E
inst✝⁴ : StarRing E
inst✝³ : CStarRing E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : IsScalarTower 𝕜 E E
inst✝ : SMulCommClass 𝕜 E E
a : E
⊢ ((fun x ↦ ‖((mul 𝕜 E) a) x‖₊) '' Metric.closedBall 0 1).Nonempty

pp: case refine_2
𝕜 : Type u_1
E : Type u_2
inst✝⁶ : DenselyNormedField 𝕜
inst✝⁵ : NonUnitalNormedRing E
inst✝⁴ : StarRing E
inst✝³ : CStarRing E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : IsScalarTower 𝕜 E E
inst✝ : SMulCommClass 𝕜 E E
a : E
⊢ ∀ a_1 ∈ (fun x ↦ ‖((mul 𝕜 E) a) x‖₊) '' Metric.closedBall 0 1, a_1 ≤ ‖a‖₊

pp: case refine_3
𝕜 : Type u_1
E : Type u_2
inst✝⁶ : DenselyNormedField 𝕜
inst✝⁵ : NonUnitalNormedRing E
inst✝⁴ : StarRing E
inst✝³ : CStarRing E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : IsScalarTower 𝕜 E E
inst✝ : SMulCommClass 𝕜 E E
a : E
r : NNReal
hr : r < ‖a‖₊
⊢ ∃ a_1 ∈ (fun x ↦ ‖((mul 𝕜 E) a) x‖₊) '' Metric.closedBall 0 1, r < a_1

Tactic:
· exact (Metric.nonempty_closedBall.mpr zero_le_one).image _

Goal state after:
case refine_2
𝕜 : Type u_1
E : Type u_2
inst✝⁶ : DenselyNormedField 𝕜
inst✝⁵ : NonUnitalNormedRing E
inst✝⁴ : StarRing E
inst✝³ : CStarRing E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : IsScalarTower 𝕜 E E
inst✝ : SMulCommClass 𝕜 E E
a : E
⊢ ∀ a_1 ∈ (fun x ↦ ‖((mul 𝕜 E) a) x‖₊) '' Metric.closedBall 0 1, a_1 ≤ ‖a‖₊

case refine_3
𝕜 : Type u_1
E : Type u_2
inst✝⁶ : DenselyNormedField 𝕜
inst✝⁵ : NonUnitalNormedRing E
inst✝⁴ : StarRing E
inst✝³ : CStarRing E
inst✝² : NormedSpace 𝕜 E
inst✝¹ : IsScalarTower 𝕜 E E
inst✝ : SMulCommClass 𝕜 E E
a : E
r : NNReal
hr : r < ‖a‖₊
⊢ ∃ a_1 ∈ (fun x ↦ ‖((mul 𝕜 E) a) x‖₊) '' Metric.closedBall 0 1, r < a_1
Module: Mathlib.Analysis.CStarAlgebra.Unitization

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝⁸ : DenselyNormedField 𝕜
inst✝⁷ : NonUnitalNormedRing E
inst✝⁶ : StarRing E
inst✝⁵ : CStarRing E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : IsScalarTower 𝕜 E E
inst✝² : SMulCommClass 𝕜 E E
inst✝¹ : StarRing 𝕜
inst✝ : StarModule 𝕜 E
x : Unitization 𝕜 E
b : E
hb : b ∈ Metric.closedBall 0 1
⊢ √(‖((algebraMap 𝕜 (E →L[𝕜] E)) x.toProd.1 + (mul 𝕜 E) x.toProd.2) b‖ ^ 2) ≤
    √‖(algebraMap 𝕜 (E →L[𝕜] E)) (x⋆ * x).toProd.1 + (mul 𝕜 E) (x⋆ * x).toProd.2‖

Tactic:
Real.sqrt_le_sqrt_iff (norm_nonneg _),

Goal state after:
𝕜 : Type u_1
E : Type u_2
inst✝⁸ : DenselyNormedField 𝕜
inst✝⁷ : NonUnitalNormedRing E
inst✝⁶ : StarRing E
inst✝⁵ : CStarRing E
inst✝⁴ : NormedSpace 𝕜 E
inst✝³ : IsScalarTower 𝕜 E E
inst✝² : SMulCommClass 𝕜 E E
inst✝¹ : StarRing 𝕜
inst✝ : StarModule 𝕜 E
x : Unitization 𝕜 E
b : E
hb : b ∈ Metric.closedBall 0 1
⊢ ‖((algebraMap 𝕜 (E →L[𝕜] E)) x.toProd.1 + (mul 𝕜 E) x.toProd.2) b‖ ^ 2 ≤
    ‖(algebraMap 𝕜 (E →L[𝕜] E)) (x⋆ * x).toProd.1 + (mul 𝕜 E) (x⋆ * x).toProd.2‖
Module: Mathlib.Topology.ContinuousMap.StoneWeierstrass

Goal state before:
pp: case h
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✝
⊢ ∃ x ∈ A, ↑restrict_on_K x = restrict_on_K g

Tactic:
use g, hg1

Goal state after:
case right
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) := ⋯
AK : Subalgebra ℝ C(↑K, ℝ) := ⋯
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✝
⊢ ↑restrict_on_K g = restrict_on_K g
Module: Mathlib.Topology.ContinuousMap.StoneWeierstrass

Goal state before:
pp: case refine_2
F : Type u_2
S : Type u_3
K : Type u_4
A : Type u_5
inst✝¹³ : CommRing K
inst✝¹² : Ring A
inst✝¹¹ : Algebra K A
inst✝¹⁰ : TopologicalSpace K
inst✝⁹ : T1Space K
inst✝⁸ : TopologicalSpace A
inst✝⁷ : ContinuousSub A
inst✝⁶ : ContinuousSMul K A
inst✝⁵ : FunLike F A K
inst✝⁴ : AlgHomClass F K A K
inst✝³ : SetLike S A
inst✝² : OneMemClass S A
inst✝¹ : AddSubgroupClass S A
inst✝ : SMulMemClass S K A
φ : F
hφ : Continuous[inst✝⁸, inst✝¹⁰] ⇑φ
s : S
⊢ closure[inst✝⁸] ↑s ∩ ↑(RingHom.ker φ) ⊆ closure[inst✝⁸] (↑s ∩ ↑(RingHom.ker φ))

Tactic:
· intro x ⟨hxs, (hxφ : φ x = 0)⟩
    rw [mem_closure_iff_clusterPt, ClusterPt] at hxs
    have : Tendsto (fun y ↦ y - φ y • 1) (𝓝 x ⊓ 𝓟 s) (𝓝 x) := by
      conv => congr; rfl; rfl; rw [← sub_zero x, ← zero_smul K 1, ← hxφ]
      exact Filter.tendsto_inf_left (Continuous.tendsto (by fun_prop) x)
    refine mem_closure_of_tendsto this <| eventually_inf_principal.mpr ?_
    filter_upwards [] with g hg using
      ⟨sub_mem hg (SMulMemClass.smul_mem _ <| one_mem _), by simp [RingHom.mem_ker]⟩

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

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
inst✝ : TopologicalSpace β
f : α → β
⊢ (∀ {u : Set α}, IsClosed[inst✝¹] u → IsClosed[inst✝] (kernImage f u)) ↔ LowerHemicontinuous fun x ↦ f ⁻¹' {x}

Tactic:
lowerHemicontinuous_iff_isClosed_preimage_Iic

Goal state after:
α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
inst✝ : TopologicalSpace β
f : α → β
⊢ (∀ {u : Set α}, IsClosed[inst✝¹] u → IsClosed[inst✝] (kernImage f u)) ↔
    ∀ (u : Set α), IsClosed[inst✝¹] u → IsClosed[inst✝] ((fun x ↦ f ⁻¹' {x}) ⁻¹' Iic u)
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
⊢ ∀ x ∈ s, LowerHemicontinuousWithinAt f s x

Tactic:
intro x₀

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
⊢ x₀ ∈ s → LowerHemicontinuousWithinAt f s x₀
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), UpperHemicontinuousOn (F n) s
hf_compact : ∀ x ∈ s, IsCompact (f x)
⊢ ∀ x ∈ s, ∀ (u : Set β), IsOpen[inst✝.toTopologicalSpace] u → f x ⊆ u → ∀ᶠ (x' : α) in 𝓝[s] x, f x' ⊆ u

Tactic:
intro x₀

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), UpperHemicontinuousOn (F n) s
hf_compact : ∀ x ∈ s, IsCompact (f x)
x₀ : α
⊢ x₀ ∈ s → ∀ (u : Set β), IsOpen[inst✝.toTopologicalSpace] u → f x₀ ⊆ u → ∀ᶠ (x' : α) in 𝓝[s] x₀, f x' ⊆ u
Module: Mathlib.Analysis.Normed.Algebra.Spectrum

Goal state before:
pp: 𝕜 : Type u_1
A : Type u_2
inst✝⁴ : NormedField 𝕜
inst✝³ : NormedRing A
inst✝² : NormedAlgebra 𝕜 A
inst✝¹ : CompleteSpace A
inst✝ : NormOneClass A
a : A
k : 𝕜
hk : k ∈ σ a
⊢ ↑‖k‖₊ ≤ ↑‖a‖₊

Tactic:
exact mod_cast norm_le_norm_of_mem hk

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

Goal state before:
pp: α : Type u_1
inst✝¹ : TopologicalSpace α
inst✝ : T2Space α
t : TopologicalSpace (Set α)
h₁ : IsOpen[t] {∅}
h₂ : ∀ {U : Set α}, IsOpen[inst✝¹] U → IsOpen[t] {s | (s ∩ U).Nonempty}
s : Set α
hs : s ∈ (range fun x ↦ {x})ᶜ
h : s.Nonempty
x : α
hx : x ∈ s
y : α
hy : y ∈ s
hxy : x ≠ y
U V : Set α
hU : IsOpen[inst✝¹] U
hV : IsOpen[inst✝¹] V
hxU : x ∈ U
hyV : y ∈ V
hUV : Disjoint U V
z : α
hzU : z ∈ U
hzV : z ∈ V
⊢ False

Tactic:
exact hUV.notMem_of_mem_left hzU hzV

Goal state after:
Module: Mathlib.Topology.UniformSpace.Closeds

Goal state before:
pp: case inr
α : Type u_1
inst✝ : UniformSpace α
s : Set α
hs : IsCompact s
U : Set α
hU : U ∈ {U | IsOpen[inst✝.toTopologicalSpace] U}
hs' : s ∈ (fun V ↦ {s | (s ∩ V).Nonempty}) U
⊢ (fun V ↦ {s | (s ∩ V).Nonempty}) U ∈ 𝓝 s

Tactic:
exact (UniformSpace.hausdorff.isOpen_inter_nonempty_of_isOpen hU).mem_nhds hs'

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

Goal state before:
pp: case neg.inl
α : Type u_1
inst✝ : TopologicalSpace α
K : Set α
hK : IsCompact K
s : Set (Set α)
hsK : s ⊆ 𝒫 K
hs : ∀ L ∈ s, IsCompact L
S : Set (Set (Set α))
hS : S ⊆ powerset '' {U | IsOpen[inst✝] U} ∪ (fun V ↦ {s | (s ∩ V).Nonempty}) '' {V | IsOpen[inst✝] V}
hKS : {t | t ⊆ K ∧ ∀ L ∈ s, (t ∩ L).Nonempty} ⊆ ⋃₀ S
u : Set (Set α) := {U | IsOpen[inst✝] U ∧ {s | (s ∩ U).Nonempty} ∈ S}
hsu : ∀ L ∈ s, (K \ ⋃₀ u ∩ L).Nonempty
U : Set α
hU : U ∈ {U | IsOpen[inst✝] U}
hUS : 𝒫 U ∈ S
hUu : K \ ⋃₀ u ∈ 𝒫 U
⊢ ∃ Q ⊆ S, Q.Finite ∧ {t | t ⊆ K ∧ ∀ L ∈ s, (t ∩ L).Nonempty} ⊆ ⋃₀ Q

Tactic:
rw [mem_powerset_iff, sdiff_subset_comm, sUnion_eq_biUnion] at hUu
      obtain ⟨T, hTS, hT, hKT⟩ := (hK.diff hU).elim_finite_subcover_image (fun _ h => h.1) hUu
      refine ⟨insert U.powerset ((fun V => {s | (s ∩ V).Nonempty}) '' T),
        insert_subset hUS <| Set.image_subset_iff.mpr <| hTS.trans fun _ h => h.2,
        (hT.image _).insert _, ?_⟩
      rw [sUnion_insert, ← sdiff_subset_iff, sUnion_image]
      rintro t ⟨⟨htK, -⟩, htU⟩
      rw [mem_powerset_iff, not_subset] at htU
      obtain ⟨x, hxt, hxU⟩ := htU
      obtain ⟨V, hVT, hxV⟩ := mem_iUnion₂.mp <| hKT ⟨htK hxt, hxU⟩
      exact mem_biUnion hVT ⟨x, hxt, hxV⟩

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

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
s : Set α
hs : IsPreconnected s
x : α
hx : x ∈ s
this : {t | t.Nonempty ∧ t.Finite ∧ t ⊆ s} = ⋃ n, range '' univ.pi fun x ↦ s
⊢ IsPreconnected (⋃ n, range '' univ.pi fun x ↦ s)

Tactic:
exact isPreconnected_iUnion
      ⟨{x}, mem_iInter_of_mem fun n => ⟨fun _ => x, by simpa⟩⟩
      (fun n => .image (isPreconnected_univ_pi fun _ => hs) _ (by fun_prop))

Goal state after:
Module: Mathlib.Topology.UniformSpace.Closeds

Goal state before:
pp: α : Type u_1
β : Type u_2
γ : Type u_3
inst✝³ : UniformSpace α
inst✝² : UniformSpace β
inst✝¹ : UniformSpace γ
inst✝ : CompleteSpace α
f : Filter (Compacts α)
x✝ : Cauchy f
left✝ : f.NeBot
hf : ∀ {U : Set (α × α)}, U ∈ 𝓤 α → ∀ᶠ (K : Compacts α) (K' : Compacts α) in f, (↑K, ↑K') ∈ hausdorffEntourage U
l : Filter α := f.lift' fun s ↦ ⋃ K ∈ s, ↑K
hl : l.TotallyBounded
L : Compacts α := { carrier := {x | ClusterPt x l}, isCompact' := ⋯ }
U : SetRel α α
hU₁ : U ∈ 𝓤 α
hU₂ : IsClosed[instTopologicalSpaceProd] U
K : Compacts α
hK : ∀ᶠ (K' : Compacts α) in f, (↑K, ↑K') ∈ hausdorffEntourage U
x : α
hx : x ∈ ↑K
lx : Filter α := l ⊓ 𝓟 (UniformSpace.ball x U)
le_def : lx = l ⊓ 𝓟 (UniformSpace.ball x U)
hlx : lx.TotallyBounded
s : Set (Compacts α)
hs : s ∈ f
⊢ ((⋃ K ∈ s, ↑K) ∩ UniformSpace.ball x U).Nonempty

Tactic:
obtain ⟨K', ⟨h₁, -⟩, h₂⟩ := Filter.nonempty_of_mem <| Filter.inter_mem hK hs

Goal state after:
α : Type u_1
β : Type u_2
γ : Type u_3
inst✝³ : UniformSpace α
inst✝² : UniformSpace β
inst✝¹ : UniformSpace γ
inst✝ : CompleteSpace α
f : Filter (Compacts α)
x✝ : Cauchy f
left✝ : f.NeBot
hf : ∀ {U : Set (α × α)}, U ∈ 𝓤 α → ∀ᶠ (K : Compacts α) (K' : Compacts α) in f, (↑K, ↑K') ∈ hausdorffEntourage U
l : Filter α := f.lift' fun s ↦ ⋃ K ∈ s, ↑K
hl : l.TotallyBounded
L : Compacts α := { carrier := {x | ClusterPt x l}, isCompact' := ⋯ }
U : SetRel α α
hU₁ : U ∈ 𝓤 α
hU₂ : IsClosed[instTopologicalSpaceProd] U
K : Compacts α
hK : ∀ᶠ (K' : Compacts α) in f, (↑K, ↑K') ∈ hausdorffEntourage U
x : α
hx : x ∈ ↑K
lx : Filter α := l ⊓ 𝓟 (UniformSpace.ball x U)
le_def : lx = l ⊓ 𝓟 (UniformSpace.ball x U)
hlx : lx.TotallyBounded
s : Set (Compacts α)
hs : s ∈ f
K' : Compacts α
h₂ : K' ∈ s
h₁ : (↑K, ↑K').1 ⊆ U.preimage (↑K, ↑K').2
⊢ ((⋃ K ∈ s, ↑K) ∩ UniformSpace.ball x U).Nonempty
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Isometric

Goal state before:
pp: 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
⊢ IsGreatest ((fun x ↦ ‖f x‖) '' σₙ 𝕜 a) ‖cfcₙ f a‖

Tactic:
obtain ⟨x, hx⟩ := NonUnitalContinuousFunctionalCalculus.isCompact_quasispectrum a
      |>.image_of_continuousOn hf.norm |>.exists_isGreatest <|
      (quasispectrum.nonempty 𝕜 a).image _
  obtain ⟨x, hx', rfl⟩ := hx.1
  convert! hx
  rw [cfcₙ_apply f a, norm_cfcₙHom a _]
  apply le_antisymm
  · apply ContinuousMap.norm_le _ (norm_nonneg _) |>.mpr
    rintro ⟨y, hy⟩
    exact hx.2 ⟨y, hy, rfl⟩
  · exact le_trans (by simp) <| ContinuousMap.norm_coe_le_norm _ (⟨x, hx'⟩ : σₙ 𝕜 a)

Goal state after:
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Isometric

Goal state before:
pp: A : Type u_1
inst✝⁷ : NormedRing A
inst✝⁶ : StarRing A
inst✝⁵ : NormedAlgebra ℝ A
inst✝⁴ : PartialOrder A
inst✝³ : StarOrderedRing A
inst✝² : IsometricContinuousFunctionalCalculus ℝ A IsSelfAdjoint
inst✝¹ : NonnegSpectrumClass ℝ A
inst✝ : Nontrivial A
f : ℝ≥0 → ℝ≥0
a : A
hf : ContinuousOn f (σ ℝ≥0 a)
ha : 0 ≤ a
ha' : SpectrumRestricts a ⇑ContinuousMap.realToNNReal
⊢ IsGreatest (f '' σ ℝ≥0 a) ‖cfc (fun x ↦ ↑(f x.toNNReal)) a‖₊

Tactic:
convert! IsGreatest.nnnorm_cfc (fun x : ℝ ↦ (f x.toNNReal : ℝ)) a ?hf_cont

Goal state after:
A : Type u_1
inst✝⁷ : NormedRing A
inst✝⁶ : StarRing A
inst✝⁵ : NormedAlgebra ℝ A
inst✝⁴ : PartialOrder A
inst✝³ : StarOrderedRing A
inst✝² : IsometricContinuousFunctionalCalculus ℝ A IsSelfAdjoint
inst✝¹ : NonnegSpectrumClass ℝ A
inst✝ : Nontrivial A
f : ℝ≥0 → ℝ≥0
a : A
hf : ContinuousOn f (σ ℝ≥0 a)
ha : 0 ≤ a
ha' : SpectrumRestricts a ⇑ContinuousMap.realToNNReal
⊢ f '' σ ℝ≥0 a = (fun x ↦ ‖↑(f x.toNNReal)‖₊) '' σ ℝ a

case hf_cont
A : Type u_1
inst✝⁷ : NormedRing A
inst✝⁶ : StarRing A
inst✝⁵ : NormedAlgebra ℝ A
inst✝⁴ : PartialOrder A
inst✝³ : StarOrderedRing A
inst✝² : IsometricContinuousFunctionalCalculus ℝ A IsSelfAdjoint
inst✝¹ : NonnegSpectrumClass ℝ A
inst✝ : Nontrivial A
f : ℝ≥0 → ℝ≥0
a : A
hf : ContinuousOn f (σ ℝ≥0 a)
ha : 0 ≤ a
ha' : SpectrumRestricts a ⇑ContinuousMap.realToNNReal
⊢ ContinuousOn (fun x ↦ ↑(f x.toNNReal)) (σ ℝ a)
Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Isometric

Goal state before:
pp: 𝕜 : Type u_1
A : Type u_2
p : A → Prop
inst✝⁴ : RCLike 𝕜
inst✝³ : NormedRing A
inst✝² : StarRing A
inst✝¹ : NormedAlgebra 𝕜 A
inst✝ : IsometricContinuousFunctionalCalculus 𝕜 A p
a : A
ha : p a
this : CompactSpace ↑(σₙ 𝕜 a)
⊢ Isometry
    ⇑((↑(cfcHom ha)).comp
        ((↑(ContinuousMap.compStarAlgHom' 𝕜 𝕜 { toFun := Set.inclusion ⋯, continuous_toFun := ⋯ })).comp
          ContinuousMapZero.toContinuousMapHom))

Tactic:
refine isometry_cfcHom a |>.comp ?_

Goal state after:
𝕜 : Type u_1
A : Type u_2
p : A → Prop
inst✝⁴ : RCLike 𝕜
inst✝³ : NormedRing A
inst✝² : StarRing A
inst✝¹ : NormedAlgebra 𝕜 A
inst✝ : IsometricContinuousFunctionalCalculus 𝕜 A p
a : A
ha : p a
this : CompactSpace ↑(σₙ 𝕜 a)
⊢ Isometry
    ⇑↑((↑(ContinuousMap.compStarAlgHom' 𝕜 𝕜 { toFun := Set.inclusion ⋯, continuous_toFun := ⋯ })).comp
            ContinuousMapZero.toContinuousMapHom).toNonUnitalAlgHom
Module: Mathlib.Analysis.LocallyConvex.Polar

Goal state before:
pp: 𝕜 : Type u_4
inst✝³ : NontriviallyNormedField 𝕜
E : Type u_5
inst✝² : AddCommMonoid E
inst✝¹ : TopologicalSpace E
inst✝ : Module 𝕜 E
a : E
⊢ polar 𝕜 {a} = {x | ‖x a‖ ≤ 1}

Tactic:
simp only [polar, LinearMap.polar_singleton, LinearMap.flip_apply, topDualPairing_apply]

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

Goal state before:
pp: case refine_2.inl
α : Type u_1
inst✝ : TopologicalSpace α
B : Set (Set α)
hB : IsTopologicalBasis B
K : NonemptyCompacts α
hu : ∅.Finite
huB : ∅ ⊆ B
hK₁ : ↑K.toCompacts ⊆ ⋃₀ ∅
hK₂ : ∀ U ∈ ∅, (↑K.toCompacts ∩ U).Nonempty
⊢ ∃ v ∈ (fun u ↦ {K | ↑K ⊆ ⋃₀ u ∧ ∀ U ∈ u, (↑K ∩ U).Nonempty}) '' {u | u.Finite ∧ u.Nonempty ∧ u ⊆ B},
    K ∈ v ∧ v ⊆ toCompacts ⁻¹' {K | ↑K ⊆ ⋃₀ ∅ ∧ ∀ U ∈ ∅, (↑K ∩ U).Nonempty}

Tactic:
absurd K.nonempty.mono hK₁; simp

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

Goal state before:
pp: case refine_1
𝕜 : Type v
inst✝² : RCLike 𝕜
E : Type u
inst✝¹ : SeminormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
x : E
h : ‖x‖ ≠ 0
hhomothety : ∀ (c : 𝕜), ‖(LinearEquiv.toSpanNonzeroSingleton 𝕜 E x ⋯) c‖ = ‖x‖ * ‖c‖
coord : ↥(𝕜 ∙ x) →L[𝕜] 𝕜 := ↑(ofHomothety (LinearEquiv.toSpanNonzeroSingleton 𝕜 E x ⋯) ‖x‖ ⋯ hhomothety).symm
g : StrongDual 𝕜 E
hg : (∀ (x_1 : ↥(𝕜 ∙ x)), g ↑x_1 = (↑‖x‖ • coord) x_1) ∧ ‖g‖ = ‖↑‖x‖ • coord‖
hval : g x = ↑‖x‖
⊢ ‖x‖ * ‖coord‖ ≤ 1

Tactic:
coord.opNorm_le_bound (by positivity)
      (fun y ↦ (homothety_inverse _ (by positivity) _ hhomothety y).le),

Goal state after:
case refine_1
𝕜 : Type v
inst✝² : RCLike 𝕜
E : Type u
inst✝¹ : SeminormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
x : E
h : ‖x‖ ≠ 0
hhomothety : ∀ (c : 𝕜), ‖(LinearEquiv.toSpanNonzeroSingleton 𝕜 E x ⋯) c‖ = ‖x‖ * ‖c‖
coord : ↥(𝕜 ∙ x) →L[𝕜] 𝕜 := ↑(ofHomothety (LinearEquiv.toSpanNonzeroSingleton 𝕜 E x ⋯) ‖x‖ ⋯ hhomothety).symm
g : StrongDual 𝕜 E
hg : (∀ (x_1 : ↥(𝕜 ∙ x)), g ↑x_1 = (↑‖x‖ • coord) x_1) ∧ ‖g‖ = ‖↑‖x‖ • coord‖
hval : g x = ↑‖x‖
⊢ ‖x‖ * ‖x‖⁻¹ ≤ 1
Module: Mathlib.Analysis.Normed.Operator.Completeness

Goal state before:
pp: 𝕜 : Type u_1
𝕜₂ : Type u_2
F : Type u_4
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NontriviallyNormedField 𝕜
inst✝⁴ : NontriviallyNormedField 𝕜₂
inst✝³ : NormedSpace 𝕜₂ F
σ₁₂ : 𝕜 →+* 𝕜₂
E' : Type u_6
inst✝² : SeminormedAddCommGroup E'
inst✝¹ : NormedSpace 𝕜 E'
inst✝ : RingHomIsometric σ₁₂
f₀ : E' →SL[σ₁₂] F
r : ℝ
f : E' →SL[σ₁₂] F
hf : ⇑f ∈ closure[Pi.topologicalSpace] (DFunLike.coe '' closedBall f₀ r)
hr : 0 ≤ r
x : E'
this : IsClosed[Pi.topologicalSpace] {g | ‖g x - f₀ x‖ ≤ r * ‖x‖}
g : E' →SL[σ₁₂] F
hg : g ∈ closedBall f₀ r
⊢ g ∈ DFunLike.coe ⁻¹' {g | ‖g x - f₀ x‖ ≤ r * ‖x‖}

Tactic:
exact (g - f₀).le_of_opNorm_le (mem_closedBall_iff_norm.1 hg) _

Goal state after:
Module: Mathlib.Analysis.LocallyConvex.Barrelled

Goal state before:
pp: α : Type u_1
ι : Type u_2
κ : Type u_3
𝕜₁ : Type u_4
𝕜₂ : Type u_5
E : Type u_6
F : Type u_7
inst✝¹⁰ : NontriviallyNormedField 𝕜₁
inst✝⁹ : NontriviallyNormedField 𝕜₂
σ₁₂ : 𝕜₁ →+* 𝕜₂
inst✝⁸ : RingHomIsometric σ₁₂
inst✝⁷ : AddCommGroup E
inst✝⁶ : AddCommGroup F
inst✝⁵ : Module 𝕜₁ E
inst✝⁴ : Module 𝕜₂ F
inst✝³ : TopologicalSpace E
inst✝² : IsTopologicalAddGroup E
inst✝¹ : ContinuousConstSMul 𝕜₁ E
inst✝ : BaireSpace E
p : Seminorm 𝕜₁ E
hp : LowerSemicontinuous ⇑p
h₁ : ∀ (n : ℕ), IsClosed[inst✝³] (p.closedBall 0 ↑n)
h₂ : ⋃ n, p.closedBall 0 ↑n = univ
n : ℕ
x : E
hxn : {y | p y ≤ ↑n} ∈ map (fun x_1 ↦ x + x_1) (𝓝 0)
hxn' : p x ≤ ↑n
y : E
hy : y ∈ (fun x_1 ↦ x + x_1) ⁻¹' {y | p y ≤ ↑n}
⊢ p y ≤ ↑n + ↑n

Tactic:
calc p y = p (x + y - x) := by rw [add_sub_cancel_left]
      _ ≤ p (x + y) + p x := map_sub_le_add _ _ _
      _ ≤ n + n := add_le_add hy hxn'

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

Goal state before:
pp: V : Type u_1
P : Type u_2
inst✝⁵ : SeminormedAddCommGroup V
inst✝⁴ : PseudoMetricSpace P
inst✝³ : NormedAddTorsor V P
𝕜 : Type u_5
inst✝² : NormedField 𝕜
inst✝¹ : NormedSpace 𝕜 V
inst✝ : Invertible 2
p₁ p₂ p₃ p₄ : P
⊢ ‖p₁ -ᵥ p₃ + (p₂ -ᵥ p₄)‖ / ‖2‖ ≤ (‖p₁ -ᵥ p₃‖ + ‖p₂ -ᵥ p₄‖) / ‖2‖

Tactic:
grw [norm_add_le]

Goal state after:
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case succ
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
x : X
n : ℕ
ihn : ∀ (c : CU P), x ∈ c.C → approx n c x = 0
c : CU P
hx : x ∈ c.C
⊢ approx (n + 1) c x = 0

Tactic:
| succ n ihn =>

Goal state after:
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case succ
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
x : X
n : ℕ
ihn : ∀ (c : CU P), x ∉ c.U → approx n c x = 1
c : CU P
hx : x ∉ c.U
⊢ approx (n + 1) c x = 1

Tactic:
| succ n ihn =>

Goal state after:
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case succ
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
x : X
n : ℕ
ihn : ∀ (c : CU P), 0 ≤ approx n c x
c : CU P
⊢ 0 ≤ approx (n + 1) c x

Tactic:
| succ n ihn =>

Goal state after:
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case succ
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
x : X
n : ℕ
ihn : ∀ (c : CU P), approx n c x ≤ 1
c : CU P
⊢ approx (n + 1) c x ≤ 1

Tactic:
| succ n ihn =>

Goal state after:
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case succ
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
x : X
n : ℕ
ihn : ∀ (c : CU P), approx n c x ∈ Icc (approx n c.right x) (approx n c.left x)
c : CU P
⊢ approx (n + 1) c x ∈ Icc (approx (n + 1) c.right x) (approx (n + 1) c.left x)

Tactic:
| succ n ihn =>

Goal state after:
Module: Mathlib.Topology.UrysohnsLemma

Goal state before:
pp: case succ
X : Type u_1
inst✝ : TopologicalSpace X
P : Set X → Set X → Prop
x : X
n : ℕ
ihn : ∀ (c : CU P), approx n c x ≤ approx (n + 1) c x
c : CU P
⊢ approx (n + 1) c x ≤ approx (n + 1 + 1) c x

Tactic:
| succ n ihn =>

Goal state after: