mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Topology.MetricSpace.Kuratowski

Goal state before:
pp: α : Type u
inst✝ : MetricSpace α
x : ℕ → α
H : DenseRange x
a b : α
e : ℝ
epos : 0 < e
n : ℕ
hn : dist a (x n) < e / 2
C : dist b (x n) - dist a (x n) = ↑(embeddingOfSubset x b) n - ↑(embeddingOfSubset x a) n
⊢ dist a b ≤ dist (embeddingOfSubset x a) (embeddingOfSubset x b) + e

Tactic:
have :=
    calc
      dist a b ≤ dist a (x n) + dist (x n) b := dist_triangle _ _ _
      _ = 2 * dist a (x n) + (dist b (x n) - dist a (x n)) := by simp [dist_comm]; ring
      _ ≤ 2 * dist a (x n) + |dist b (x n) - dist a (x n)| := by grw [← le_abs_self]
      _ ≤ 2 * (e / 2) + |embeddingOfSubset x b n - embeddingOfSubset x a n| := by
        rw [C]
        gcongr
      _ ≤ 2 * (e / 2) + dist (embeddingOfSubset x b) (embeddingOfSubset x a) := by
        gcongr
        simp only [dist_eq_norm]
        exact lp.norm_apply_le_norm ENNReal.top_ne_zero
          (embeddingOfSubset x b - embeddingOfSubset x a) n
      _ = dist (embeddingOfSubset x b) (embeddingOfSubset x a) + e := by ring

Goal state after:
α : Type u
inst✝ : MetricSpace α
x : ℕ → α
H : DenseRange x
a b : α
e : ℝ
epos : 0 < e
n : ℕ
hn : dist a (x n) < e / 2
C : dist b (x n) - dist a (x n) = ↑(embeddingOfSubset x b) n - ↑(embeddingOfSubset x a) n
this : dist a b ≤ dist (embeddingOfSubset x b) (embeddingOfSubset x a) + e
⊢ dist a b ≤ dist (embeddingOfSubset x a) (embeddingOfSubset x b) + e
Module: Mathlib.Topology.MetricSpace.Kuratowski

Goal state before:
pp: case h
α : Type u
inst✝¹ : MetricSpace α
inst✝ : SeparableSpace α
h : univ = ∅
x : α
⊢ ∀ (x2 : α), edist ((fun x ↦ 0) x) ((fun x ↦ 0) x2) = edist x x2

Tactic:
exact absurd h (Nonempty.ne_empty ⟨x, mem_univ x⟩)

Goal state after:
Module: Mathlib.Topology.MetricSpace.CoveringNumbers

Goal state before:
pp: case refine_1
X : Type u_1
inst✝ : PseudoEMetricSpace X
A : Set X
ε : ℝ≥0
C' : Set X
hC'_subset : C' ⊆ A
hC'_cover : IsCover ε A C'
hC'_fin : C'.Finite
this : Nonempty { s // s ⊆ A ∧ IsCover ε A s }
C : { s // s ⊆ A ∧ IsCover ε A s }
hC : (↑C).encard = ⨅ x, (↑x).encard
⊢ (↑C).encard < ⊤

Tactic:
simp only [hC, iInf_lt_top, encard_lt_top_iff, Subtype.exists, exists_prop]

Goal state after:
case refine_1
X : Type u_1
inst✝ : PseudoEMetricSpace X
A : Set X
ε : ℝ≥0
C' : Set X
hC'_subset : C' ⊆ A
hC'_cover : IsCover ε A C'
hC'_fin : C'.Finite
this : Nonempty { s // s ⊆ A ∧ IsCover ε A s }
C : { s // s ⊆ A ∧ IsCover ε A s }
hC : (↑C).encard = ⨅ x, (↑x).encard
⊢ ∃ a, (a ⊆ A ∧ IsCover ε A a) ∧ a.Finite
Module: Mathlib.Topology.MetricSpace.CoveringNumbers

Goal state before:
pp: X : Type u_1
inst✝ : PseudoEMetricSpace X
A : Set X
ε : ℝ≥0
h : packingNumber ε A ≠ ⊤
x : X
hxA : x ∈ A
⊢ ∃ y ∈ maximalSeparatedSet ε A, (x, y) ∈ {(x, y) | edist x y ≤ ↑ε}

Tactic:
by_contra! h_dist

Goal state after:
X : Type u_1
inst✝ : PseudoEMetricSpace X
A : Set X
ε : ℝ≥0
h : packingNumber ε A ≠ ⊤
x : X
hxA : x ∈ A
h_dist : ∀ y ∈ maximalSeparatedSet ε A, (x, y) ∉ {x | edist x.1 x.2 ≤ ↑ε}
⊢ False
Module: Mathlib.Topology.MetricSpace.HolderNorm

Goal state before:
pp: X : Type u_1
Y : Type u_2
inst✝¹ : PseudoEMetricSpace X
inst✝ : PseudoEMetricSpace Y
r : ℝ≥0
c : Y
⊢ nnHolderNorm r (Function.const X c) = 0

Tactic:
by
  rw [← nonpos_iff_eq_zero, ← ENNReal.coe_le_coe, ENNReal.coe_zero, ← eHolderNorm_const X r c]
  exact coe_nnHolderNorm_le_eHolderNorm

Goal state after:
Module: Mathlib.Topology.MetricSpace.Ultra.TotallySeparated

Goal state before:
pp: X : Type u_1
inst✝¹ : MetricSpace X
inst✝ : IsUltrametricDist X
x y : X
h : x ≠ y
⊢ (fun x1 x2 ↦ ∃ U, IsClopen U ∧ x1 ∈ U ∧ x2 ∈ Uᶜ) x y

Tactic:
obtain ⟨r, hr, hr'⟩ := exists_between (dist_pos.mpr h)
    refine ⟨_, IsUltrametricDist.isClopen_ball x r, ?_, ?_⟩
    · simp only [mem_ball, dist_self, hr]
    · simp only [Set.mem_compl, mem_ball, dist_comm, not_lt, hr'.le]

Goal state after:
Module: Mathlib.Topology.MetricSpace.Snowflaking

Goal state before:
pp: X : Type u_1
α : ℝ
hα₀ : 0 < α
hα₁ : α ≤ 1
inst✝ : PseudoEMetricSpace X
x : Snowflaking X α hα₀ hα₁
d : ℝ≥0∞
⊢ ⇑toSnowflaking ⁻¹' eball x d = eball (ofSnowflaking x) (d ^ α⁻¹)

Tactic:
by
  rw [toSnowflaking.preimage_eq_iff_eq_image, image_toSnowflaking_eball,
    toSnowflaking_ofSnowflaking, ENNReal.rpow_inv_rpow hα₀.ne']

Goal state after:
Module: Mathlib.Topology.MetricSpace.Snowflaking

Goal state before:
pp: X : Type u_1
α : ℝ
hα₀ : 0 < α
hα₁ : α ≤ 1
inst✝ : PseudoMetricSpace X
x : X
r : ℝ
hr : 0 ≤ r
⊢ ⇑ofSnowflaking ⁻¹' closedBall x r = closedBall (toSnowflaking x) (r ^ α)

Tactic:
by
  ext ⟨y⟩
  simp (disch := positivity) [Real.rpow_le_rpow_iff]

Goal state after:
Module: Mathlib.Topology.NatEmbedding

Goal state before:
pp: case refine_1
X : Type u_1
inst✝² : TopologicalSpace X
inst✝¹ : T2Space X
inst✝ : Infinite X
U : ℕ → Set X
hne : ∀ (n : ℕ), (U n).Nonempty
ho : ∀ (n : ℕ), IsOpen[inst✝²] (U n)
hd : Pairwise (Disjoint on U)
n i j : ℕ
hij : U (Nat.pair n i) = U (Nat.pair n j)
⊢ i = j

Tactic:
suffices n.pair i = n.pair j by simpa

Goal state after:
case refine_1
X : Type u_1
inst✝² : TopologicalSpace X
inst✝¹ : T2Space X
inst✝ : Infinite X
U : ℕ → Set X
hne : ∀ (n : ℕ), (U n).Nonempty
ho : ∀ (n : ℕ), IsOpen[inst✝²] (U n)
hd : Pairwise (Disjoint on U)
n i j : ℕ
hij : U (Nat.pair n i) = U (Nat.pair n j)
⊢ Nat.pair n i = Nat.pair n j
Module: Mathlib.Topology.Order.UpperLowerSetTopology

Goal state before:
pp: α : Type u_1
inst✝¹ : Preorder α
inst✝ : TopologicalSpace α
⊢ Topology.IsUpperSet αᵒᵈ ↔ Topology.IsLowerSet α

Tactic:
constructor
  · apply OrderDual.instIsLowerSet
  · apply OrderDual.instIsUpperSet

Goal state after:
Module: Mathlib.Topology.MetricSpace.GromovHausdorff

Goal state before:
pp: case inr
X : Type u
inst✝⁵ : MetricSpace X
inst✝⁴ : CompactSpace X
inst✝³ : Nonempty X
Y : Type v
inst✝² : MetricSpace Y
inst✝¹ : CompactSpace Y
inst✝ : Nonempty Y
inhabited_h✝ : Inhabited X
inhabited_h : Inhabited Y
p q : NonemptyCompacts ↥(lp (fun n ↦ ℝ) ∞)
hp : ⟦p⟧ = toGHSpace X
hq : ⟦q⟧ = toGHSpace Y
bound : hausdorffDist ↑p ↑q < diam univ + 1 + diam univ
Φ : X → ↥(lp (fun n ↦ ℝ) ∞)
Φisom : Isometry Φ
Φrange : range Φ = ↑p
Ψ : Y → ↥(lp (fun n ↦ ℝ) ∞)
Ψisom : Isometry Ψ
Ψrange : range Ψ = ↑q
I : diam (range Φ ∪ range Ψ) ≤ 2 * diam univ + 1 + 2 * diam univ
f : X ⊕ Y → ↥(lp (fun n ↦ ℝ) ∞) :=
  fun x ↦
    match x with
    | inl y => Φ y
    | inr z => Ψ z
F : (X ⊕ Y) × (X ⊕ Y) → ℝ := fun p ↦ dist (f p.1) (f p.2)
x y : X ⊕ Y
val✝ : Y
⊢ f (inr val✝) ∈ range Φ ∪ range Ψ

Tactic:
· apply mem_union_right; apply mem_range_self

Goal state after:
Module: Mathlib.Topology.Order.Completion

Goal state before:
pp: case refine_2
α : Type u_1
inst✝² : LinearOrder α
inst✝¹ : TopologicalSpace α
inst✝ : OrderTopology α
x : α
q : ℚ
x✝ : (IsSuccPrelimit x → 0 ≤ q) ∧ (IsPredPrelimit x → q ≤ 0)
hx₁ : IsSuccPrelimit x → 0 ≤ q
hx₂ : IsPredPrelimit x → q ≤ 0
⊢ IsOpen (⇑some ⁻¹' Iio ⟨toLex (x, q), ⋯⟩)

Tactic:
· obtain hq | hq := le_or_gt q 0
    · convert isOpen_Iio (a := x)
      ext
      simp [some, Prod.Lex.lt_iff, hq.not_gt]
    · obtain ⟨y, hy⟩ := not_isPredPrelimit_iff.1 <| mt hx₂ hq.not_ge
      convert isOpen_Iio (a := y)
      ext
      simpa [some, Prod.Lex.lt_iff, hq, le_iff_lt_or_eq] using hy.le_iff_lt_left

Goal state after:
Module: Mathlib.Topology.Order.NhdsSet

Goal state before:
pp: α : Type u_1
inst✝² : LinearOrder α
inst✝¹ : TopologicalSpace α
inst✝ : OrderTopology α
a : α
h : Nonempty ↑(Ioi a)
⊢ (𝓝ˢ (Iic a)).HasBasis (fun x ↦ a < x) Iio

Tactic:
refine ⟨fun s ↦ ⟨fun hs ↦ ?_, fun ⟨b, hab, hb⟩ ↦ mem_of_superset (Iio_mem_nhdsSet_Iic hab) hb⟩⟩

Goal state after:
α : Type u_1
inst✝² : LinearOrder α
inst✝¹ : TopologicalSpace α
inst✝ : OrderTopology α
a : α
h : Nonempty ↑(Ioi a)
s : Set α
hs : s ∈ 𝓝ˢ (Iic a)
⊢ ∃ i, a < i ∧ Iio i ⊆ s
Module: Mathlib.Topology.Order.LawsonTopology

Goal state before:
pp: α : Type u_1
inst✝² : Preorder α
inst✝¹ : TopologicalSpace α
inst✝ : IsLawson α
lawsonBasis_image2 :
  lawsonBasis α =
    image2 (fun x x_1 ↦ ⇑WithLower.toLower ⁻¹' x ∩ ⇑WithScott.toScott ⁻¹' x_1) (IsLower.lowerBasis (WithLower α))
      {U | IsOpen[scott α univ] U}
x✝ : TopologicalSpace α := scott α univ
⊢ scott α univ = induced (⇑WithScott.toScott) WithScott.instTopologicalSpace

Tactic:
exact (@IsScott.withScottHomeomorph α _ (scott α univ) ⟨rfl⟩).isInducing.eq_induced

Goal state after:
Module: Mathlib.Topology.Order.LawsonTopology

Goal state before:
pp: α : Type u_1
inst✝² : Preorder α
L S : TopologicalSpace α
inst✝¹ : IsLawson α
inst✝ : IsScott α univ
⊢ L ≤ S

Tactic:
rw [@IsScott.topology_eq α univ _ S _, @IsLawson.topology_eq_lawson α _ L _]

Goal state after:
α : Type u_1
inst✝² : Preorder α
L S : TopologicalSpace α
inst✝¹ : IsLawson α
inst✝ : IsScott α univ
⊢ lawson α ≤ scott α univ
Module: Mathlib.Topology.Separation.Lemmas

Goal state before:
pp: X : Type u_1
inst✝ : MetricSpace X
s : Set X
hs : s.Countable
⊢ IsTotallyDisconnected s

Tactic:
rw [← totallyDisconnectedSpace_subtype_iff]

Goal state after:
X : Type u_1
inst✝ : MetricSpace X
s : Set X
hs : s.Countable
⊢ TotallyDisconnectedSpace ↑s
Module: Mathlib.Topology.Separation.Lemmas

Goal state before:
pp: X : Type u_1
inst✝ : MetricSpace X
s : Set X
hs : s.Countable
⊢ IsTotallyDisconnected s

Tactic:
by
  rw [← totallyDisconnectedSpace_subtype_iff]
  have : Countable s := hs
  infer_instance

Goal state after:
Module: Mathlib.Topology.Separation.NotNormal

Goal state before:
pp: X : Type u
inst✝² : TopologicalSpace X
inst✝¹ : NormalSpace X
s d : Set X
hs : IsClosed s
inst✝ : DiscreteTopology ↑s
hd : Dense d
h_closed : ∀ t ∈ 𝒫 s, IsClosed t
U V : ↑(𝒫 s) → Set X
hU : ∀ (t : ↑(𝒫 s)), IsOpen (U t)
hV : ∀ (t : ↑(𝒫 s)), IsOpen (V t)
hUs : ∀ (t : ↑(𝒫 s)), ↑t ⊆ U t
hVs : ∀ (t : ↑(𝒫 s)), s \ ↑t ⊆ V t
hUV : ∀ (t : ↑(𝒫 s)), Disjoint (U t) (V t)
t₁ t₂ : ↑(𝒫 s)
h : U t₁ ∩ d = U t₂ ∩ d
⊢ ↑t₁ ⊆ ↑t₂

Tactic:
by_contra ht

Goal state after:
X : Type u
inst✝² : TopologicalSpace X
inst✝¹ : NormalSpace X
s d : Set X
hs : IsClosed s
inst✝ : DiscreteTopology ↑s
hd : Dense d
h_closed : ∀ t ∈ 𝒫 s, IsClosed t
U V : ↑(𝒫 s) → Set X
hU : ∀ (t : ↑(𝒫 s)), IsOpen (U t)
hV : ∀ (t : ↑(𝒫 s)), IsOpen (V t)
hUs : ∀ (t : ↑(𝒫 s)), ↑t ⊆ U t
hVs : ∀ (t : ↑(𝒫 s)), s \ ↑t ⊆ V t
hUV : ∀ (t : ↑(𝒫 s)), Disjoint (U t) (V t)
t₁ t₂ : ↑(𝒫 s)
h : U t₁ ∩ d = U t₂ ∩ d
ht : ¬↑t₁ ⊆ ↑t₂
⊢ False
Module: Mathlib.Topology.Sheaves.PUnit

Goal state before:
pp: case inl
C : Type u
inst✝ : Category.{v, u} C
X : TopCat
hind : X.str = ⊤
F : Presheaf C X
it : IsTerminal (F.obj (op ⊥))
c : C
this : IndiscreteTopology ↑X
s : Sieve ⊥
hs✝ : s ∈ (Opens.grothendieckTopology ↑X) ⊥
x✝ : Presieve.FamilyOfElements (F ⋙ coyoneda.obj (op c)) s.arrows
a✝ : x✝.Compatible
U : TopologicalSpace.Opens ↑X
hU : U ⟶ ⊥
hs : s.arrows hU
⊢ IsTerminal (F.obj (op U))

Tactic:
le_bot_iff.1 hU.le

Goal state after:
case inl
C : Type u
inst✝ : Category.{v, u} C
X : TopCat
hind : X.str = ⊤
F : Presheaf C X
it : IsTerminal (F.obj (op ⊥))
c : C
this : IndiscreteTopology ↑X
s : Sieve ⊥
hs✝ : s ∈ (Opens.grothendieckTopology ↑X) ⊥
x✝ : Presieve.FamilyOfElements (F ⋙ coyoneda.obj (op c)) s.arrows
a✝ : x✝.Compatible
U : TopologicalSpace.Opens ↑X
hU : U ⟶ ⊥
hs : s.arrows hU
⊢ IsTerminal (F.obj (op ⊥))
Module: Mathlib.Topology.Sheaves.Skyscraper

Goal state before:
pp: X : TopCat
p₀ : ↑X
inst✝² : (U : Opens ↑X) → Decidable (p₀ ∈ U)
C : Type v
inst✝¹ : Category.{u, v} C
A : C
inst✝ : HasTerminal C
y : ↑X
h✝ : p₀ ⤳ y
c : Cocone ((OpenNhds.inclusion y).op ⋙ skyscraperPresheaf p₀ A)
f : (skyscraperPresheafCoconeOfSpecializes p₀ A h✝).pt ⟶ c.pt
h : ∀ (j : (OpenNhds y)ᵒᵖ), (skyscraperPresheafCoconeOfSpecializes p₀ A h✝).ι.app j ≫ f = c.ι.app j
⊢ f = eqToHom ⋯ ≫ f

Tactic:
eqToHom_refl,

Goal state after:
X : TopCat
p₀ : ↑X
inst✝² : (U : Opens ↑X) → Decidable (p₀ ∈ U)
C : Type v
inst✝¹ : Category.{u, v} C
A : C
inst✝ : HasTerminal C
y : ↑X
h✝ : p₀ ⤳ y
c : Cocone ((OpenNhds.inclusion y).op ⋙ skyscraperPresheaf p₀ A)
f : (skyscraperPresheafCoconeOfSpecializes p₀ A h✝).pt ⟶ c.pt
h : ∀ (j : (OpenNhds y)ᵒᵖ), (skyscraperPresheafCoconeOfSpecializes p₀ A h✝).ι.app j ≫ f = c.ι.app j
⊢ f = 𝟙 A ≫ f
Module: Mathlib.Topology.Sheaves.Skyscraper

Goal state before:
pp: X : TopCat
p₀ : ↑X
inst✝³ : (U : Opens ↑X) → Decidable (p₀ ∈ U)
C : Type v
inst✝² : Category.{u, v} C
inst✝¹ : HasTerminal C
inst✝ : HasColimits C
𝓕 : Presheaf C X
c : C
f : 𝓕.stalk p₀ ⟶ c
U : Opens ↑X
hxU : p₀ ∈ U
⊢ 𝓕.germ (unop (op U)) p₀ hxU ≫ f ≫ eqToHom ⋯ = 𝓕.germ U p₀ hxU ≫ f

Tactic:
eqToHom_refl,

Goal state after:
X : TopCat
p₀ : ↑X
inst✝³ : (U : Opens ↑X) → Decidable (p₀ ∈ U)
C : Type v
inst✝² : Category.{u, v} C
inst✝¹ : HasTerminal C
inst✝ : HasColimits C
𝓕 : Presheaf C X
c : C
f : 𝓕.stalk p₀ ⟶ c
U : Opens ↑X
hxU : p₀ ∈ U
⊢ 𝓕.germ (unop (op U)) p₀ hxU ≫ f ≫ 𝟙 c = 𝓕.germ U p₀ hxU ≫ f
Module: Mathlib.Topology.Sheaves.EtaleSpace

Goal state before:
pp: X : TopCat
C : Type u
inst✝⁴ : Category.{v, u} C
CC : C → Type v
FC : C → C → Type w
inst✝³ : (X Y : C) → FunLike (FC X Y) (CC X) (CC Y)
inst✝² : ConcreteCategory C FC
inst✝¹ : Limits.HasColimits C
F : Presheaf C X
inst✝ : Limits.PreservesFilteredColimits (forget C)
⊢ Continuous base

Tactic:
by
  rw [continuous_iff_continuousAt]
  intro x
  rw [ContinuousAt, (nhds_basis_opens _).tendsto_right_iff]
  rintro U ⟨hxU, hUo⟩
  lift U to Opens X using hUo
  rcases F.exists_le_germ_eq x.germ hxU with ⟨V, hVU, hxV, f, hf⟩
  refine x.eventually_nhds hxV f hf |>.mono ?_
  aesop

Goal state after:
Module: Mathlib.Topology.Sheaves.Alexandrov

Goal state before:
pp: X : Type v
inst✝⁵ : TopologicalSpace X
inst✝⁴ : Preorder X
inst✝³ : Topology.IsUpperSet X
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasLimits C
F : X ⥤ C
P : (Opens X)ᵒᵖ ⥤ C
η : principals X ⋙ P ⟶ F
inst✝ : P.IsRightKanExtension η
γ : principals X ⋙ principalsKanExtension F ⟶ F := (principals X).pointwiseRightKanExtensionCounit F
x✝ : (principalsKanExtension F).IsRightKanExtension γ := inferInstance
this : P ≅ principalsKanExtension F
⊢ CategoryTheory.Presheaf.IsSheaf (Opens.grothendieckTopology X) P

Tactic:
change TopCat.Presheaf.IsSheaf (X := TopCat.of X) P

Goal state after:
X : Type v
inst✝⁵ : TopologicalSpace X
inst✝⁴ : Preorder X
inst✝³ : Topology.IsUpperSet X
C : Type u
inst✝² : Category.{v, u} C
inst✝¹ : HasLimits C
F : X ⥤ C
P : (Opens X)ᵒᵖ ⥤ C
η : principals X ⋙ P ⟶ F
inst✝ : P.IsRightKanExtension η
γ : principals X ⋙ principalsKanExtension F ⟶ F := (principals X).pointwiseRightKanExtensionCounit F
x✝ : (principalsKanExtension F).IsRightKanExtension γ := inferInstance
this : P ≅ principalsKanExtension F
⊢ TopCat.Presheaf.IsSheaf P
Module: Mathlib.Topology.MetricSpace.GromovHausdorff

Goal state before:
pp: t : Set GHSpace
C : ℝ
u : ℕ → ℝ
K : ℕ → ℕ
ulim : Tendsto u atTop (𝓝 0)
hdiam : ∀ p ∈ t, diam univ ≤ C
hcov : ∀ p ∈ t, ∀ (n : ℕ), ∃ s, #↑s ≤ ↑(K n) ∧ univ ⊆ ⋃ x ∈ s, ball x (u n)
δ : ℝ
δpos : δ > 0
ε : ℝ := 1 / 5 * δ
εpos : 0 < ε
n : ℕ
hn : ∀ n_1 ≥ n, dist (u n_1) 0 < ε
u_le_ε : u n ≤ ε
s : (p : GHSpace) → Set p.Rep
N : GHSpace → ℕ
hN : ∀ (p : GHSpace), N p ≤ K n
E : (p : GHSpace) → ↑(s p) ≃ Fin (N p)
hs : ∀ p ∈ t, univ ⊆ ⋃ x ∈ s p, ball x (u n)
M : ℕ := ⌊ε⁻¹ * max C 0⌋₊
F : GHSpace → (k : Fin (K n).succ) × (Fin ↑k → Fin ↑k → Fin M.succ) :=
  fun p ↦ ⟨⟨N p, ⋯⟩, fun a b ↦ ⟨min M ⌊ε⁻¹ * dist ((E p).symm a) ((E p).symm b)⌋₊, ⋯⟩⟩
p : GHSpace
pt : p ∈ t
q : GHSpace
qt : q ∈ t
hpq : (fun p ↦ F ↑p) ⟨p, pt⟩ = (fun p ↦ F ↑p) ⟨q, qt⟩
Npq : N p = N q
Ψ : ↑(s p) → ↑(s q) := fun x ↦ (E q).symm (Fin.cast Npq ((E p) x))
Φ : ↑(s p) → q.Rep := fun x ↦ ↑(Ψ x)
x y : ↑(s p)
this : dist (Φ x) (Φ y) = dist (Ψ x) (Ψ y)
i : ℕ := ↑((E p) x)
hip : i < N p
hiq : i < N q
i' : i = ↑((E q) (Ψ x))
j : ℕ := ↑((E p) y)
hjp : j < N p
hjq : j < N q
j' : j = ↑((E q) (Ψ y))
⊢ ↑((F p).snd ⟨i, hip⟩ ⟨j, hjp⟩) = ↑((F p).snd ((E p) x) ((E p) y))

Tactic:
by
            congr

Goal state after:
Module: Mathlib.Topology.Sion

Goal state before:
pp: E : Type u_1
F : Type u_2
β : Type u_3
inst✝⁸ : LinearOrder β
X : Set E
Y : Set F
f : E → F → β
inst✝⁷ : TopologicalSpace E
inst✝⁶ : AddCommGroup E
inst✝⁵ : Module ℝ E
inst✝⁴ : IsTopologicalAddGroup E
inst✝³ : ContinuousSMul ℝ E
ne_X : X.Nonempty
kX : IsCompact X
hfy : ∀ y ∈ Y, LowerSemicontinuousOn (fun x ↦ f x y) X
hfy' : ∀ y ∈ Y, QuasiconvexOn ℝ X fun x ↦ f x y
inst✝² : TopologicalSpace F
inst✝¹ : AddCommGroup F
inst✝ : Module ℝ F
cY : Convex ℝ Y
hfx : ∀ x ∈ X, UpperSemicontinuousOn (fun y ↦ f x y) Y
hfx' : ∀ x ∈ X, QuasiconcaveOn ℝ Y fun y ↦ f x y
a : E
b b' : β
y y' : ↑Y
ha : ∀ x ∈ X, max (f a ↑y) (f a ↑y') ≤ max (f x ↑y) (f x ↑y')
hb : ∀ y ∈ Y, ∃ x ∈ X, f x y ≤ b
hb' : b' < max (f a ↑y) (f a ↑y')
hbb' : b < b'
J : Set ↑(segment ℝ ↑y ↑y') := ⋯
z : ↑(segment ℝ ↑y ↑y')
hz : ClusterPt z (𝓟 J)
x : ↑X
hx : x ∈ sublevelLeft X f b ↑z
z' : ↑(segment ℝ ↑y ↑y')
hz' : z' ∈ setOfPred_sublevelLeft_subset X Y f b b' y y'
hxz' : x ∈ sublevelLeft X f b' ↑z'
⊢ ¬sublevelLeft X f b' ↑z' ⊆ sublevelLeft X f b' ↑y'

Tactic:
intro hz'2

Goal state after:
E : Type u_1
F : Type u_2
β : Type u_3
inst✝⁸ : LinearOrder β
X : Set E
Y : Set F
f : E → F → β
inst✝⁷ : TopologicalSpace E
inst✝⁶ : AddCommGroup E
inst✝⁵ : Module ℝ E
inst✝⁴ : IsTopologicalAddGroup E
inst✝³ : ContinuousSMul ℝ E
ne_X : X.Nonempty
kX : IsCompact X
hfy : ∀ y ∈ Y, LowerSemicontinuousOn (fun x ↦ f x y) X
hfy' : ∀ y ∈ Y, QuasiconvexOn ℝ X fun x ↦ f x y
inst✝² : TopologicalSpace F
inst✝¹ : AddCommGroup F
inst✝ : Module ℝ F
cY : Convex ℝ Y
hfx : ∀ x ∈ X, UpperSemicontinuousOn (fun y ↦ f x y) Y
hfx' : ∀ x ∈ X, QuasiconcaveOn ℝ Y fun y ↦ f x y
a : E
b b' : β
y y' : ↑Y
ha : ∀ x ∈ X, max (f a ↑y) (f a ↑y') ≤ max (f x ↑y) (f x ↑y')
hb : ∀ y ∈ Y, ∃ x ∈ X, f x y ≤ b
hb' : b' < max (f a ↑y) (f a ↑y')
hbb' : b < b'
J : Set ↑(segment ℝ ↑y ↑y') := setOfPred_sublevelLeft_subset X Y f b b' y y'
z : ↑(segment ℝ ↑y ↑y')
hz : ClusterPt z (𝓟 J)
x : ↑X
hx : x ∈ sublevelLeft X f b ↑z
z' : ↑(segment ℝ ↑y ↑y')
hz' : z' ∈ setOfPred_sublevelLeft_subset X Y f b b' y y'
hxz' : x ∈ sublevelLeft X f b' ↑z'
hz'2 : sublevelLeft X f b' ↑z' ⊆ sublevelLeft X f b' ↑y'
⊢ False
Module: Mathlib.Topology.SmallInductiveDimension

Goal state before:
pp: X : Type u_1
inst✝ : TopologicalSpace X
n : ℕ
hle : HasSmallInductiveDimensionLE X n
hlt : ¬HasSmallInductiveDimensionLT X n
⊢ smallInductiveDimension X = ↑n

Tactic:
by
  apply (smallInductiveDimension_le_iff.2 hle).antisymm
  rwa [← not_lt, smallInductiveDimension_lt_iff]

Goal state after:
Module: Mathlib.Topology.UniformSpace.OfCompactT2

Goal state before:
pp: case refine_1
γ : Type u_1
inst✝² : TopologicalSpace γ
inst✝¹ : CompactSpace γ
inst✝ : R1Space γ
𝓝Δ : Filter (γ × γ) := 𝓝ˢ (diagonal γ)
F : Filter (γ × γ) := 𝓝Δ.lift' fun s ↦ s ○ s
V : Set (γ × γ)
V_in : V ∈ 𝓝Δ
H : ¬F ⊓ 𝓟 Vᶜ = ⊥
this : (F ⊓ 𝓟 Vᶜ).NeBot
x y : γ
hxy : ClusterPt (x, y) (F ⊓ 𝓟 Vᶜ)
clV : ClusterPt (x, y) (𝓟 Vᶜ)
ninsep_xy : ¬Inseparable x y
U₁ V₁ : Set γ
V₁_in : V₁ ∈ 𝓝 x
U₂ V₂ : Set γ
V₂_in : V₂ ∈ 𝓝 y
V₁_cl : IsClosed[inst✝²] V₁
V₂_cl : IsClosed[inst✝²] V₂
U₁_op : IsOpen[inst✝²] U₁
U₂_op : IsOpen[inst✝²] U₂
VU₁ : V₁ ⊆ U₁
VU₂ : V₂ ⊆ U₂
hU₁₂ : Disjoint U₁ U₂
U₃ : Set γ := (V₁ ∪ V₂)ᶜ
U₃_op : IsOpen[inst✝²] U₃
W : Set (γ × γ) := U₁ ×ˢ U₁ ∪ U₂ ×ˢ U₂ ∪ U₃ ×ˢ U₃
z z' : γ
hzz' : (z, z') ∈ diagonal γ
⊢ IsOpen[instTopologicalSpaceProd] W

Tactic:
apply_rules [IsOpen.union, IsOpen.prod]

Goal state after:
Module: Mathlib.Topology.VectorBundle.ContinuousAlternatingMap

Goal state before:
pp: 𝕜 : Type u_1
ι : Type u_2
inst✝¹⁹ : NontriviallyNormedField 𝕜
B : Type u_3
inst✝¹⁸ : TopologicalSpace B
F₁ : Type u_4
inst✝¹⁷ : NormedAddCommGroup F₁
inst✝¹⁶ : NormedSpace 𝕜 F₁
E₁ : B → Type u_5
inst✝¹⁵ : (x : B) → AddCommGroup (E₁ x)
inst✝¹⁴ : (x : B) → Module 𝕜 (E₁ x)
inst✝¹³ : TopologicalSpace (TotalSpace F₁ E₁)
F₂ : Type u_6
inst✝¹² : NormedAddCommGroup F₂
inst✝¹¹ : NormedSpace 𝕜 F₂
E₂ : B → Type u_7
inst✝¹⁰ : (x : B) → AddCommGroup (E₂ x)
inst✝⁹ : (x : B) → Module 𝕜 (E₂ x)
inst✝⁸ : TopologicalSpace (TotalSpace F₂ E₂)
inst✝⁷ : (x : B) → TopologicalSpace (E₁ x)
inst✝⁶ : FiberBundle F₁ E₁
inst✝⁵ : (x : B) → TopologicalSpace (E₂ x)
inst✝⁴ : FiberBundle F₂ E₂
e₁ e₁' : Trivialization F₁ TotalSpace.proj
e₂ e₂' : Trivialization F₂ TotalSpace.proj
inst✝³ : Trivialization.IsLinear 𝕜 e₁
inst✝² : Trivialization.IsLinear 𝕜 e₁'
inst✝¹ : Trivialization.IsLinear 𝕜 e₂
inst✝ : Trivialization.IsLinear 𝕜 e₂'
b : B
hb : b ∈ e₁.baseSet ∩ e₂.baseSet ∩ (e₁'.baseSet ∩ e₂'.baseSet)
L : F₁ [⋀^ι]→L[𝕜] F₂
⊢ (continuousAlternatingMapCoordChange 𝕜 ι e₁ e₁' e₂ e₂' b) L =
    (↑(continuousAlternatingMap 𝕜 ι e₁' e₂') { proj := b, snd := (continuousAlternatingMap 𝕜 ι e₁ e₂).symm b L }).2

Tactic:
by
  ext v
  simp only [mem_inter_iff] at hb
  simp [continuousAlternatingMapCoordChange, continuousAlternatingMap_apply,
    Function.comp_def, Trivialization.coordChangeL_apply,
    continuousAlternatingMap_symm_apply' hb.left, hb]

Goal state after: