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

Goal state before:
pp: 𝕜 : Type u_1
inst✝ : RCLike 𝕜
s : Set 𝕜
x : C(↑s, 𝕜)
⊢ x ∈ StarAlgebra.adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)} ↔
    x ∈ span 𝕜 ({1} ∪ ↑(adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}))

Tactic:
← StarAlgebra.adjoin_nonUnitalStarSubalgebra,

Goal state after:
𝕜 : Type u_1
inst✝ : RCLike 𝕜
s : Set 𝕜
x : C(↑s, 𝕜)
⊢ x ∈ StarAlgebra.adjoin 𝕜 ↑(adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}) ↔
    x ∈ span 𝕜 ({1} ∪ ↑(adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}))
Module: Mathlib.Topology.ContinuousMap.StoneWeierstrass

Goal state before:
pp: 𝕜 : Type u_1
inst✝ : RCLike 𝕜
s : Set 𝕜
x : C(↑s, 𝕜)
⊢ x ∈ StarAlgebra.adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)} ↔
    x ∈ ↑(𝕜 ∙ 1) + ↑(adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)})

Tactic:
← StarAlgebra.adjoin_nonUnitalStarSubalgebra,

Goal state after:
𝕜 : Type u_1
inst✝ : RCLike 𝕜
s : Set 𝕜
x : C(↑s, 𝕜)
⊢ x ∈ StarAlgebra.adjoin 𝕜 ↑(adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}) ↔
    x ∈ ↑(𝕜 ∙ 1) + ↑(adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)})
Module: Mathlib.Topology.ContinuousMap.StoneWeierstrass

Goal state before:
pp: case mp
𝕜 : Type u_1
inst✝ : RCLike 𝕜
s : Set 𝕜
h0 : 0 ∈ s
r : 𝕜
f : C(↑s, 𝕜)
hf : f ∈ adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}
hf₂ : (r • 1) ⟨0, h0⟩ = 0
this : f ⟨0, h0⟩ = 0
⊢ r • 1 + f ∈ adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}

Tactic:
smul_apply,

Goal state after:
case mp
𝕜 : Type u_1
inst✝ : RCLike 𝕜
s : Set 𝕜
h0 : 0 ∈ s
r : 𝕜
f : C(↑s, 𝕜)
hf : f ∈ adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}
hf₂ : r • 1 ⟨0, h0⟩ = 0
this : f ⟨0, h0⟩ = 0
⊢ r • 1 + f ∈ adjoin 𝕜 {restrict s (ContinuousMap.id 𝕜)}
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
⊢ IsOpenMap f ↔ LowerHemicontinuous fun x ↦ f ⁻¹' {x}

Tactic:
isOpenMap_iff_kernImage,

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)) ↔ LowerHemicontinuous fun x ↦ f ⁻¹' {x}
Module: Mathlib.Topology.Semicontinuity.Hemicontinuity

Goal state before:
pp: α : Type u_3
β : Type u_4
inst✝² : TopologicalSpace α
inst✝¹ : TopologicalSpace β
f : α → Set β
s : Set α
γ : Type u_5
inst✝ : TopologicalSpace γ
i : γ → β
hf : UpperHemicontinuousOn f s
hi : IsInducing i
h_cl : IsClosed[inst✝¹] (range i)
⊢ UpperHemicontinuousOn (fun x ↦ i ⁻¹' f x) s

Tactic:
by
  rw [upperHemicontinuousOn_iff] at hf ⊢
  exact fun x hx ↦ (hf x hx).isInducing_comp hi h_cl

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

Goal state before:
pp: α : Type u_3
β : Type u_4
inst✝² : TopologicalSpace α
inst✝¹ : TopologicalSpace β
f : α → Set β
x₀ : α
inst✝ : (𝓝 x₀).IsCountablyGenerated
K : Set β
hK : IsSeqCompact K
hf : ∀ᶠ (x : α) in 𝓝 x₀, f x ⊆ K
h :
  ∀ (x : ℕ → α),
    Tendsto x atTop (𝓝 x₀) → ∀ (y : ℕ → β), (∀ (n : ℕ), y n ∈ f (x n)) → ∀ (y₀ : β), Tendsto y atTop (𝓝 y₀) → y₀ ∈ f x₀
t : Set β
ht : IsClosed[inst✝¹] t
hft : ∃ᶠ (x' : α) in 𝓝 x₀, (f x' ∩ t).Nonempty
x : ℕ → α
hx : Tendsto x atTop (𝓝 x₀)
y : ℕ → β
hy : ∀ (n : ℕ), y n ∈ f (x n) ∩ t
⊢ ∃ᶠ (n : ℕ) in atTop, y n ∈ K

Tactic:
refine Eventually.frequently ?_
    filter_upwards [hx hf] with n hn
    exact hn (hy n).1

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

Goal state before:
pp: α : Type u_1
U V : SetRel α α
h : U ⊆ V
⊢ hausdorffEntourage U ⊆ hausdorffEntourage V

Tactic:
unfold hausdorffEntourage
  gcongr

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

Goal state before:
pp: case neg
𝕜 : Type u_1
A : Type u_2
inst✝³ : NontriviallyNormedField 𝕜
inst✝² : NormedRing A
inst✝¹ : NormedAlgebra 𝕜 A
inst✝ : HasSummableGeomSeries A
a : A
r : ℝ≥0
hr : r * ‖a‖₊ < 1
n : ℕ
h : ¬‖a‖₊ = 0
⊢ ‖a‖₊ ^ n.succ * r ^ (n + 1) ≤ 1

Tactic:
simpa only [← mul_pow, mul_comm] using! pow_le_one' hr.le n.succ

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

Goal state before:
pp: case inr.inr
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
⊢ (range fun x ↦ {x})ᶜ ∈ 𝓝 s

Tactic:
filter_upwards [(h₂ hU).inter (h₂ hV) |>.mem_nhds ⟨⟨x, hx, hxU⟩, ⟨y, hy, hyV⟩⟩]

Goal state after:
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
⊢ ∀ a ∈ {s | (s ∩ U).Nonempty} ∩ {s | (s ∩ V).Nonempty}, a ∈ (range fun x ↦ {x})ᶜ
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
⊢ (↑K, ↑L) ∈ hausdorffEntourage (id U)

Tactic:
id,

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
⊢ (↑K, ↑L) ∈ hausdorffEntourage U
Module: Mathlib.Topology.Sets.VietorisTopology

Goal state before:
pp: case refine_2.inr
α : Type u_1
inst✝ : TopologicalSpace α
s t : Set α
x✝ : (∀ x ∈ s, ∃ y ∈ t, x ⤳ y) ∧ t ⊆ closure[inst✝] s
hst : ∀ x ∈ s, ∃ y ∈ t, x ⤳ y
hts : t ⊆ closure[inst✝] s
U : Set α
hU : U ∈ {U | IsOpen[inst✝] U}
x : α
hxt : x ∈ t
hxU : x ∈ U
y : α
hyU : y ∈ U
hys : y ∈ s
⊢ ⨅
      s_1 ∈
        {s_2 |
          s ∈ s_2 ∧
            s_2 ∈ powerset '' {U | IsOpen[inst✝] U} ∪ (fun V ↦ {s | (s ∩ V).Nonempty}) '' {V | IsOpen[inst✝] V}},
      Filter.principal s_1 ≤
    Filter.principal ((fun V ↦ {s | (s ∩ V).Nonempty}) U)

Tactic:
exact iInf₂_le {t | (t ∩ U).Nonempty} ⟨⟨y, hys, hyU⟩, .inr <| mem_image_of_mem _ hU⟩

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

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
s t : Set α
⊢ s ⤳ t ↔ (∀ x ∈ s, ∃ y ∈ t, x ⤳ y) ∧ t ⊆ closure[inst✝] s

Tactic:
refine ⟨fun h => ⟨fun x hx => ?_, subset_closure_of_specializes h⟩, fun ⟨hst, hts⟩ => ?_⟩
  · obtain ⟨y, hyt, hxy⟩ := h.mem_closed (s := {u | (u ∩ closure {x}).Nonempty})
      (isClosed_inter_nonempty_of_isClosed isClosed_closure) ⟨x, hx, subset_closure rfl⟩
    exact ⟨y, hyt, specializes_iff_mem_closure.mpr hxy⟩
  · simp_rw [Specializes, nhds_generateFrom, le_iInf₂_iff]
    rintro _ ⟨hs, ⟨U, hU, rfl⟩ | ⟨U, hU, rfl⟩⟩
    · refine iInf₂_le U.powerset ⟨fun x hx => ?_, .inl <| mem_image_of_mem _ hU⟩
      obtain ⟨y, hyt, hxy⟩ := hst x hx
      exact hxy.mem_open hU <| hs hyt
    · obtain ⟨x, hxt, hxU⟩ := hs
      obtain ⟨y, hyU, hys⟩ := mem_closure_iff.mp (hts hxt) U hU hxU
      exact iInf₂_le {t | (t ∩ U).Nonempty} ⟨⟨y, hys, hyU⟩, .inr <| mem_image_of_mem _ hU⟩

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

Goal state before:
pp: case inr
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
f : 𝕜 → 𝕜
a : A
c : ℝ
hc : 0 < c
h : ∀ x ∈ σ 𝕜 a, ‖f x‖ < c
h✝ : Nontrivial A
⊢ ‖cfc f a‖ < c

Tactic:
refine cfc_cases (‖·‖ < c) a f (by simpa) fun hf ha ↦ ?_
    simp only [← cfc_apply f a, (IsGreatest.norm_cfc f a hf ha |>.lt_iff)]
    rintro - ⟨x, hx, rfl⟩
    exact h x hx

Goal state after:
Module: Mathlib.Analysis.CStarAlgebra.Spectrum

Goal state before:
pp: A : Type u_1
inst✝ : CStarAlgebra A
S : StarSubalgebra ℂ A
hS : IsClosed[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] ↑S
a : ↥S
⊢ IsUnit ↑a ↔ IsUnit a

Tactic:
by
  refine ⟨fun ha ↦ ?_, IsUnit.map S.subtype⟩
  have ha₁ := ha.star.mul ha
  have ha₂ := ha.mul ha.star
  have spec_eq {x : S} (hx : IsSelfAdjoint x) : spectrum ℂ x = spectrum ℂ (x : A) :=
    Subalgebra.spectrum_eq_of_isPreconnected_compl S _ <|
      (hx.map S.subtype).isConnected_spectrum_compl.isPreconnected
  rw [← StarMemClass.coe_star, ← MulMemClass.coe_mul, ← spectrum.zero_notMem_iff ℂ, ← spec_eq,
    spectrum.zero_notMem_iff] at ha₁ ha₂
  · have h₁ : ha₁.unit⁻¹ * star a * a = 1 := mul_assoc _ _ a ▸ ha₁.val_inv_mul
    have h₂ : a * (star a * ha₂.unit⁻¹) = 1 := (mul_assoc a _ _).symm ▸ ha₂.mul_val_inv
    exact ⟨⟨a, ha₁.unit⁻¹ * star a, left_inv_eq_right_inv h₁ h₂ ▸ h₂, h₁⟩, rfl⟩
  · exact IsSelfAdjoint.mul_star_self a
  · exact IsSelfAdjoint.star_mul_self a

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

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
S : Set (Compacts α)
hS : IsCompact S
ι : Type u_1
U : ι → Set α
hU : ∀ (i : ι), IsOpen[inst✝] (U i)
h : ∀ i ∈ S, ↑i ⊆ ⋃ i, U i
⊢ ∃ t, ⋃ K ∈ S, ↑K ⊆ ⋃ i ∈ t, U i

Tactic:
obtain ⟨s, hs⟩ := hS.elim_finite_subcover
    (fun s : Finset ι => {K | (K : Set α) ⊆ ⋃ i ∈ s, U i})
    (fun s => isOpen_subsets_of_isOpen <| isOpen_biUnion fun _ _ => hU _)
    (fun K hK => mem_iUnion.mpr <| K.isCompact.elim_finite_subcover U hU <| h K hK)

Goal state after:
α : Type u_1
inst✝ : TopologicalSpace α
S : Set (Compacts α)
hS : IsCompact S
ι : Type u_1
U : ι → Set α
hU : ∀ (i : ι), IsOpen[inst✝] (U i)
h : ∀ i ∈ S, ↑i ⊆ ⋃ i, U i
s : Finset (Finset ι)
hs : S ⊆ ⋃ i ∈ s, {K | ↑K ⊆ ⋃ i_1 ∈ i, U i_1}
⊢ ∃ t, ⋃ K ∈ S, ↑K ⊆ ⋃ i ∈ t, U i
Module: Mathlib.Analysis.LocallyConvex.Polar

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁴ : NormedCommRing 𝕜
inst✝³ : AddCommMonoid E
inst✝² : AddCommMonoid F
inst✝¹ : Module 𝕜 E
inst✝ : Module 𝕜 F
B : E →ₗ[𝕜] F →ₗ[𝕜] 𝕜
s : Set E
⊢ IsClosed[WeakBilin.instTopologicalSpace B.flip] (B.polar s)

Tactic:
rw [polar_eq_biInter_preimage]
  exact isClosed_biInter
    fun _ _ ↦ Metric.isClosed_closedBall.preimage (WeakBilin.eval_continuous B.flip _)

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
f : α →ᵇ β
hf : ∀ U ∈ 𝓝 f, (U ∩ range toBCF).Nonempty
⊢ Tendsto (⇑f) (cocompact α) (𝓝 0)

Tactic:
refine Metric.tendsto_nhds.mpr fun ε hε => ?_

Goal state after:
α : Type u
β : Type v
inst✝² : TopologicalSpace α
inst✝¹ : PseudoMetricSpace β
inst✝ : Zero β
f : α →ᵇ β
hf : ∀ U ∈ 𝓝 f, (U ∩ range toBCF).Nonempty
ε : ℝ
hε : ε > 0
⊢ ∀ᶠ (x : α) in cocompact α, dist (f x) 0 < ε
Module: Mathlib.Analysis.CStarAlgebra.Fuglede

Goal state before:
pp: A : Type u_2
inst✝ : NonUnitalCStarAlgebra A
a b x : A
ha : IsStarNormal a
hb : IsStarNormal b
h : SemiconjBy x a b
⊢ SemiconjBy ↑x ↑a ↑b

Tactic:
simpa [SemiconjBy] using mod_cast h.eq

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

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
F : Type u_3
inst✝⁴ : NontriviallyNormedField 𝕜
inst✝³ : AddCommMonoid E
inst✝² : AddCommMonoid F
inst✝¹ : Module 𝕜 E
inst✝ : Module 𝕜 F
B : E →ₗ[𝕜] F →ₗ[𝕜] 𝕜
h : B.SeparatingRight
y : F
hy : y ∈ B.polar Set.univ
x : E
ε : ℝ
hε : 0 < ε
c : 𝕜
hc : 0 < ‖c‖
hcε : ‖c‖ < ε
⊢ ‖c‖ * ‖(B (c⁻¹ • x)) y‖ ≤ ε * 1

Tactic:
by gcongr; exact hy _ trivial

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

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
inst✝⁶ : RCLike 𝕜
inst✝⁵ : AddCommGroup E
inst✝⁴ : TopologicalSpace E
inst✝³ : Module 𝕜 E
inst✝² : Module ℝ E
inst✝¹ : IsScalarTower ℝ 𝕜 E
inst✝ : ContinuousSMul ℝ E
s : AbsConvexOpenSets 𝕜 E
⊢ (gaugeSeminormFamily 𝕜 E s).ball 0 1 = ↑s

Tactic:
by
  dsimp only [gaugeSeminormFamily]
  rw [Seminorm.ball_zero_eq]
  simp_rw [gaugeSeminorm_toFun]
  exact setOfPred_gauge_lt_one_eq_self_of_isOpen (s.coe_convex.lift ℝ) s.coe_zero_mem s.coe_isOpen

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

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
⊢ IsOpen {⊥}ᶜ

Tactic:
exact Compacts.isClopen_singleton_bot.compl.isOpen

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

Goal state before:
pp: case refine_3
α : Type u_1
inst✝ : TopologicalSpace α
h : LocallyConnectedSpace (NonemptyCompacts α)
x : α
U : Set α
x✝ : x ∈ U ∧ IsOpen[inst✝] U
hx : x ∈ U
hU : IsOpen[inst✝] U
V : Set (NonemptyCompacts α)
hV₁ : IsOpen V
hV₂ : IsPreconnected V
hxV : {x} ∈ V
hKV : V ⊆ {K | ↑K ⊆ U}
⊢ id (⋃ L ∈ V, ↑L) ⊆ U

Tactic:
id,

Goal state after:
case refine_3
α : Type u_1
inst✝ : TopologicalSpace α
h : LocallyConnectedSpace (NonemptyCompacts α)
x : α
U : Set α
x✝ : x ∈ U ∧ IsOpen[inst✝] U
hx : x ∈ U
hU : IsOpen[inst✝] U
V : Set (NonemptyCompacts α)
hV₁ : IsOpen V
hV₂ : IsPreconnected V
hxV : {x} ∈ V
hKV : V ⊆ {K | ↑K ⊆ U}
⊢ ⋃ L ∈ V, ↑L ⊆ U
Module: Mathlib.Analysis.LocallyConvex.WeakDual

Goal state before:
pp: ι : Type u_4
𝕜 : Type u_5
E : Type u_6
inst✝⁵ : Finite ι
inst✝⁴ : Field 𝕜
t𝕜 : TopologicalSpace 𝕜
inst✝³ : IsTopologicalRing 𝕜
inst✝² : AddCommGroup E
inst✝¹ : Module 𝕜 E
inst✝ : T0Space 𝕜
f : ι → E →ₗ[𝕜] 𝕜
φ : E →ₗ[𝕜] 𝕜
x✝ : TopologicalSpace E := ⨅ i, induced (⇑(f i)) t𝕜
φ_cont : Continuous[⨅ i, induced (⇑(f i)) t𝕜, t𝕜] ⇑φ
x : E
hx : ∀ (i : ι), (f i) x = 0
⊢ Inseparable x 0

Tactic:
Inseparable,

Goal state after:
ι : Type u_4
𝕜 : Type u_5
E : Type u_6
inst✝⁵ : Finite ι
inst✝⁴ : Field 𝕜
t𝕜 : TopologicalSpace 𝕜
inst✝³ : IsTopologicalRing 𝕜
inst✝² : AddCommGroup E
inst✝¹ : Module 𝕜 E
inst✝ : T0Space 𝕜
f : ι → E →ₗ[𝕜] 𝕜
φ : E →ₗ[𝕜] 𝕜
x✝ : TopologicalSpace E := ⨅ i, induced (⇑(f i)) t𝕜
φ_cont : Continuous[⨅ i, induced (⇑(f i)) t𝕜, t𝕜] ⇑φ
x : E
hx : ∀ (i : ι), (f i) x = 0
⊢ 𝓝 x = 𝓝 0
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⁻¹ • x' ∈ polar 𝕜 s

Tactic:
by_cases c_zero : c = 0

Goal state after:
case pos
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
⊢ c⁻¹ • x' ∈ polar 𝕜 s

case neg
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
⊢ c⁻¹ • x' ∈ polar 𝕜 s
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
c : 𝕜
hc : 1 < ‖c‖
r : ℝ
hr : 0 < r
x' : StrongDual 𝕜 E
hx' : x' ∈ polar 𝕜 (ball 0 r)
⊢ x' ∈ closedBall 0 (‖c‖ / r)

Tactic:
StrongDual.mem_polar_iff

Goal state after:
𝕜 : Type u_1
inst✝² : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹ : SeminormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
c : 𝕜
hc : 1 < ‖c‖
r : ℝ
hr : 0 < r
x' : StrongDual 𝕜 E
hx' : ∀ z ∈ ball 0 r, ‖x' z‖ ≤ 1
⊢ x' ∈ closedBall 0 (‖c‖ / r)
Module: Mathlib.Analysis.LocallyConvex.WeakDual

Goal state before:
pp: ι : Type u_4
𝕜 : Type u_5
E : Type u_6
inst✝² : NontriviallyNormedField 𝕜
inst✝¹ : AddCommGroup E
inst✝ : Module 𝕜 E
f : ι → E →ₗ[𝕜] 𝕜
φ : E →ₗ[𝕜] 𝕜
⊢ φ ∈ Submodule.span 𝕜 (Set.range f) ↔ Continuous[⨅ i, induced (⇑(f i)) inferInstance, inferInstance] ⇑φ

Tactic:
let t𝕜 : TopologicalSpace 𝕜 := inferInstance
  let t₁ : TopologicalSpace E := ⨅ i, induced (f i) t𝕜
  let t₂ (s : Finset ι) : TopologicalSpace E := ⨅ i : s, induced (f i) t𝕜
  suffices
      Continuous[t₁, t𝕜] φ ↔ ∃ s : Finset ι, Continuous[t₂ s, t𝕜] φ by
    simp_rw [this, ← mem_span_iff_continuous_of_finite, Submodule.span_range_eq_iSup,
      iSup_subtype]
    rw [Submodule.mem_iSup_iff_exists_finset]
  have t₁_group : @IsTopologicalAddGroup E t₁ _ :=
    topologicalAddGroup_iInf fun _ ↦ topologicalAddGroup_induced _
  have t₂_group (s : Finset ι) : @IsTopologicalAddGroup E (t₂ s) _ :=
    topologicalAddGroup_iInf fun _ ↦ topologicalAddGroup_induced _
  have t₁_smul : @ContinuousSMul 𝕜 E _ _ t₁ :=
    continuousSMul_iInf fun _ ↦ continuousSMul_induced _
  have t₂_smul (s : Finset ι) : @ContinuousSMul 𝕜 E _ _ (t₂ s) :=
    continuousSMul_iInf fun _ ↦ continuousSMul_induced _
  simp_rw [WithSeminorms.continuous_iff_continuous_comp (norm_withSeminorms 𝕜 𝕜), forall_const]
  conv in Continuous _ => rw [Seminorm.continuous_iff one_pos, nhds_iInf]
  conv in Continuous _ =>
    rw [letI := t₂ s; Seminorm.continuous_iff one_pos, nhds_iInf, iInf_subtype]
  rw [Filter.mem_iInf_finite]

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
⊢ Continuous[inst✝³, _] ⇑p

Tactic:
rcases nonempty_interior_of_iUnion_of_closed h₁ h₂ with ⟨n, ⟨x, hxn⟩⟩

Goal state after:
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 : x ∈ interior (p.closedBall 0 ↑n)
⊢ Continuous[inst✝³, _] ⇑p
Module: Mathlib.Topology.ContinuousMap.ContinuousSqrt

Goal state before:
pp: 𝕜 : Type u_1
inst✝ : RCLike 𝕜
x : 𝕜 × 𝕜
hx : 0 ≤ x.2 - x.1
⊢ x.2 = x.1 + ↑√(re (x.2 - x.1)) * ↑√(re (x.2 - x.1))

Tactic:
obtain hx' := nonneg_iff.mp hx |>.right

Goal state after:
𝕜 : Type u_1
inst✝ : RCLike 𝕜
x : 𝕜 × 𝕜
hx : 0 ≤ x.2 - x.1
hx' : im (x.2 - x.1) = 0
⊢ x.2 = x.1 + ↑√(re (x.2 - x.1)) * ↑√(re (x.2 - x.1))
Module: Mathlib.Topology.ContinuousMap.Ideals

Goal state before:
pp: case refine_4
X : Type u_1
𝕜 : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : TopologicalSpace X
inst✝¹ : CompactSpace X
inst✝ : T2Space X
I : Ideal C(X, 𝕜)
f : C(X, 𝕜)
hf : f ∈ idealOfSet 𝕜 (setOfIdeal I)
ε : ℝ≥0
hε : 0 < ε
t : Set X := {x | ε / 2 ≤ ‖f x‖₊}
ht : IsClosed t
htI : Disjoint t (setOfIdeal I)ᶜ
x : X
g : C(X, 𝕜)
hI : g ∈ I
hgx : g x ≠ 0
⊢ ∃ t_1 ∈ nhdsWithin x t, ∃ g', (↑(algebraMapCLM ℝ≥0 𝕜)).comp g' ∈ I ∧ ∀ x ∈ t_1, 0 < g' x

Tactic:
have := (map_continuous g).continuousAt.eventually_ne hgx

Goal state after:
case refine_4
X : Type u_1
𝕜 : Type u_2
inst✝³ : RCLike 𝕜
inst✝² : TopologicalSpace X
inst✝¹ : CompactSpace X
inst✝ : T2Space X
I : Ideal C(X, 𝕜)
f : C(X, 𝕜)
hf : f ∈ idealOfSet 𝕜 (setOfIdeal I)
ε : ℝ≥0
hε : 0 < ε
t : Set X := {x | ε / 2 ≤ ‖f x‖₊}
ht : IsClosed t
htI : Disjoint t (setOfIdeal I)ᶜ
x : X
g : C(X, 𝕜)
hI : g ∈ I
hgx : g x ≠ 0
this : ∀ᶠ (z : X) in nhds x, g z ≠ 0
⊢ ∃ t_1 ∈ nhdsWithin x t, ∃ g', (↑(algebraMapCLM ℝ≥0 𝕜)).comp g' ∈ I ∧ ∀ x ∈ t_1, 0 < g' x
Module: Mathlib.Analysis.CStarAlgebra.GelfandDuality

Goal state before:
pp: A : Type u_1
inst✝ : NonUnitalCommCStarAlgebra A
a b : A
h : a * b = 0
f : A → C(↑(characterSpace ℂ (Unitization ℂ A)), ℂ) :=
  ⇑(gelfandStarTransform (Unitization ℂ A)) ∘ ⇑(inrNonUnitalAlgHom ℂ A)
hf : Isometry f
⊢ ‖a + b‖ = max ‖a‖ ‖b‖

Tactic:
← hf.norm_map_of_map_zero (by simp [f]),

Goal state after:
A : Type u_1
inst✝ : NonUnitalCommCStarAlgebra A
a b : A
h : a * b = 0
f : A → C(↑(characterSpace ℂ (Unitization ℂ A)), ℂ) :=
  ⇑(gelfandStarTransform (Unitization ℂ A)) ∘ ⇑(inrNonUnitalAlgHom ℂ A)
hf : Isometry f
⊢ ‖f (a + b)‖ = max ‖f a‖ ‖f b‖
Module: Mathlib.Analysis.SpecialFunctions.ContinuousFunctionalCalculus.Rpow.Basic

Goal state before:
pp: A : Type u_1
inst✝⁹ : PartialOrder A
inst✝⁸ : Ring A
inst✝⁷ : StarRing A
inst✝⁶ : TopologicalSpace A
inst✝⁵ : StarOrderedRing A
inst✝⁴ : Algebra ℝ A
inst✝³ : ContinuousFunctionalCalculus ℝ A IsSelfAdjoint
inst✝² : NonnegSpectrumClass ℝ A
inst✝¹ : IsSemitopologicalRing A
inst✝ : T2Space A
a : A
x : ℝ≥0
ha : 0 ≤ a
hx : x = 0
⊢ sqrt a ^ ↑x = a ^ (↑x / 2)

Tactic:
have ha' : 0 ≤ sqrt a := sqrt_nonneg _
    simp [hx, rpow_zero _ ha', rpow_zero _ ha]

Goal state after:
Module: Mathlib.Analysis.CStarAlgebra.ApproximateUnit

Goal state before:
pp: A : Type u_1
inst✝² : NonUnitalCStarAlgebra A
inst✝¹ : PartialOrder A
inst✝ : StarOrderedRing A
a b : A
hab : ↑a ≤ ↑b
ha : 0 ≤ ↑a
hb : 0 ≤ ↑b
c : Unitization ℂ A
hc : 0 ≤ c
⊢ 1 - cfc (fun x ↦ x⁻¹) (cfc (fun x ↦ 1 + x) c) = 1 - cfc (fun x ↦ x⁻¹) (1 + c)

pp: A : Type u_1
inst✝² : NonUnitalCStarAlgebra A
inst✝¹ : PartialOrder A
inst✝ : StarOrderedRing A
a b : A
hab : ↑a ≤ ↑b
ha : 0 ≤ ↑a
hb : 0 ≤ ↑b
c : Unitization ℂ A
hc : 0 ≤ c
⊢ ContinuousOn (fun x ↦ x⁻¹) ((fun x ↦ 1 + x) '' σ ℝ≥0 c)

Tactic:
cfc_add ..,

Goal state after:
A : Type u_1
inst✝² : NonUnitalCStarAlgebra A
inst✝¹ : PartialOrder A
inst✝ : StarOrderedRing A
a b : A
hab : ↑a ≤ ↑b
ha : 0 ≤ ↑a
hb : 0 ≤ ↑b
c : Unitization ℂ A
hc : 0 ≤ c
⊢ 1 - cfc (fun x ↦ x⁻¹) (cfc (fun x ↦ 1) c + cfc (fun x ↦ x) c) = 1 - cfc (fun x ↦ x⁻¹) (1 + c)

A : Type u_1
inst✝² : NonUnitalCStarAlgebra A
inst✝¹ : PartialOrder A
inst✝ : StarOrderedRing A
a b : A
hab : ↑a ≤ ↑b
ha : 0 ≤ ↑a
hb : 0 ≤ ↑b
c : Unitization ℂ A
hc : 0 ≤ c
⊢ ContinuousOn (fun x ↦ x⁻¹) ((fun x ↦ 1 + x) '' σ ℝ≥0 c)
Module: Mathlib.Analysis.CStarAlgebra.Module.Constructions

Goal state before:
pp: A : Type u_1
inst✝⁷ : NonUnitalCStarAlgebra A
inst✝⁶ : PartialOrder A
ι : Type u_2
E : ι → Type u_3
inst✝⁵ : Fintype ι
inst✝⁴ : (i : ι) → NormedAddCommGroup (E i)
inst✝³ : (i : ι) → Module ℂ (E i)
inst✝² : (i : ι) → SMul A (E i)
inst✝¹ : (i : ι) → CStarModule A (E i)
inst✝ : StarOrderedRing A
x : C⋆ᵐᵒᵈ(A, (i : ι) → E i)
⊢ ‖(equiv A ((i : ι) → E i)) x‖ ≤ ‖x‖

Tactic:
let _ : NormedAddCommGroup C⋆ᵐᵒᵈ(A, Π i, E i) := normedAddCommGroup A
  rw [pi_norm_le_iff_of_nonneg (by positivity)]
  simpa using norm_apply_le_norm x

Goal state after:
Module: Mathlib.Analysis.CStarAlgebra.ApproximateUnit

Goal state before:
pp: A : Type u_1
inst✝² : NonUnitalCStarAlgebra A
inst✝¹ : PartialOrder A
inst✝ : StarOrderedRing A
f : ℝ≥0 → ℝ≥0 := fun x ↦ 1 - (1 + x)⁻¹
g : ℝ≥0 → ℝ≥0 := fun x ↦ x * (1 - x)⁻¹
⊢ DirectedOn (fun x1 x2 ↦ x1 ≤ x2) ({x | 0 ≤ x} ∩ Metric.ball 0 1)

Tactic:
suffices ∀ a b : A, 0 ≤ a → 0 ≤ b → ‖a‖ < 1 → ‖b‖ < 1 →
      a ≤ cfcₙ f (cfcₙ g a + cfcₙ g b) by
    rintro a ⟨(ha₁ : 0 ≤ a), ha₂⟩ b ⟨(hb₁ : 0 ≤ b), hb₂⟩
    simp only [Metric.mem_ball, dist_zero_right] at ha₂ hb₂
    refine ⟨cfcₙ f (cfcₙ g a + cfcₙ g b), ⟨by simp, ?_⟩, ?_, ?_⟩
    · simpa only [Metric.mem_ball, dist_zero_right] using norm_cfcₙ_one_sub_one_add_inv_lt_one _
    · exact this a b ha₁ hb₁ ha₂ hb₂
    · exact add_comm (cfcₙ g a) (cfcₙ g b) ▸ this b a hb₁ ha₁ hb₂ ha₂

Goal state after:
A : Type u_1
inst✝² : NonUnitalCStarAlgebra A
inst✝¹ : PartialOrder A
inst✝ : StarOrderedRing A
f : ℝ≥0 → ℝ≥0 := fun x ↦ 1 - (1 + x)⁻¹
g : ℝ≥0 → ℝ≥0 := fun x ↦ x * (1 - x)⁻¹
⊢ ∀ (a b : A), 0 ≤ a → 0 ≤ b → ‖a‖ < 1 → ‖b‖ < 1 → a ≤ cfcₙ f (cfcₙ g a + cfcₙ g b)