mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Topology.Category.Profinite.Nobeling.Span

Goal state before:
pp: case neg.h₁
I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
s : Finset I
inst✝ : WellFoundedLT I
x : ↑(π C fun x ↦ x ∈ s)
l : List I := ⋯
a : I
as : List I
ha : List.IsChain (fun x1 x2 ↦ x1 > x2) (a :: as)
c : Products I →₀ ℤ
hc : ↑c.support ⊆ {m | ↑m ≤ as}
hmap :
  ∀ (g : Products I → ℤ → LocallyConstant ↑(π C fun x ↦ x ∈ s) ℤ),
    e (π C fun x ↦ x ∈ s) a * c.sum g = c.sum fun a_1 b ↦ e (π C fun x ↦ x ∈ s) a * g a_1 b
h✝ : ¬↑x a = true
⊢ ∀ (c_1 : Products I),
    c c_1 ≠ 0 →
      c c_1 • Products.eval (π C fun x ↦ x ∈ s) c_1 ∈
        Submodule.span ℤ (Products.eval (π C fun x ↦ x ∈ s) '' {m | ↑m ≤ a :: as})

Tactic:
intro m

Goal state after:
case neg.h₁
I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
s : Finset I
inst✝ : WellFoundedLT I
x : ↑(π C fun x ↦ x ∈ s)
l : List I := s.sort fun x1 x2 ↦ x1 ≥ x2
a : I
as : List I
ha : List.IsChain (fun x1 x2 ↦ x1 > x2) (a :: as)
c : Products I →₀ ℤ
hc : ↑c.support ⊆ {m | ↑m ≤ as}
hmap :
  ∀ (g : Products I → ℤ → LocallyConstant ↑(π C fun x ↦ x ∈ s) ℤ),
    e (π C fun x ↦ x ∈ s) a * c.sum g = c.sum fun a_1 b ↦ e (π C fun x ↦ x ∈ s) a * g a_1 b
h✝ : ¬↑x a = true
m : Products I
⊢ c m ≠ 0 →
    c m • Products.eval (π C fun x ↦ x ∈ s) m ∈
      Submodule.span ℤ (Products.eval (π C fun x ↦ x ∈ s) '' {m | ↑m ≤ a :: as})
Module: Mathlib.Topology.Category.Profinite.Nobeling.Basic

Goal state before:
pp: I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
l : Products I
o : Ordinal.{u}
hl : ∀ i ∈ ↑l, ord I i < o
f : LocallyConstant ↑C ℤ
⊢ ∀ (a : Products I), a < l ∧ eval C a = f ↔ a < l ∧ (πs C o) (eval (π C fun x ↦ ord I x < o) a) = f

Tactic:
intro m

Goal state after:
I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
l : Products I
o : Ordinal.{u}
hl : ∀ i ∈ ↑l, ord I i < o
f : LocallyConstant ↑C ℤ
m : Products I
⊢ m < l ∧ eval C m = f ↔ m < l ∧ (πs C o) (eval (π C fun x ↦ ord I x < o) m) = f
Module: Mathlib.Topology.Category.Profinite.Nobeling.Basic

Goal state before:
pp: I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
l : Products I
o₁ o₂ : Ordinal.{u}
h : o₁ ≤ o₂
hl : ∀ i ∈ ↑l, ord I i < o₁
f : LocallyConstant ↑(π C fun x ↦ ord I x < o₂) ℤ
⊢ ∀ (a : Products I),
    a < l ∧ eval (π C fun x ↦ ord I x < o₂) a = f ↔ a < l ∧ (πs' C h) (eval (π C fun x ↦ ord I x < o₁) a) = f

Tactic:
intro m

Goal state after:
I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
l : Products I
o₁ o₂ : Ordinal.{u}
h : o₁ ≤ o₂
hl : ∀ i ∈ ↑l, ord I i < o₁
f : LocallyConstant ↑(π C fun x ↦ ord I x < o₂) ℤ
m : Products I
⊢ m < l ∧ eval (π C fun x ↦ ord I x < o₂) m = f ↔ m < l ∧ (πs' C h) (eval (π C fun x ↦ ord I x < o₁) m) = f
Module: Mathlib.Topology.Category.Profinite.Nobeling.Induction

Goal state before:
pp: I : Type u
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
o : Ordinal.{u}
ho : Order.IsSuccLimit o
h : ∀ o' < o, P I o'
hho : o ≤ Ordinal.type fun x1 x2 ↦ x1 < x2
C : Set (I → Bool)
hC : IsClosed C
hsC : contained C o
⊢ LinearIndependent ℤ fun (p : ↑(⋃ e, smaller C ↑e)) ↦ ↑p

Tactic:
linearIndependent_subtype_iff

Goal state after:
I : Type u
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
o : Ordinal.{u}
ho : Order.IsSuccLimit o
h : ∀ o' < o, P I o'
hho : o ≤ Ordinal.type fun x1 x2 ↦ x1 < x2
C : Set (I → Bool)
hC : IsClosed C
hsC : contained C o
⊢ LinearIndepOn ℤ id (⋃ e, smaller C ↑e)
Module: Mathlib.Topology.Category.Stonean.Adjunctions

Goal state before:
pp: X : Type u
Y : Stonean
this : TopologicalSpace X := ⊥
⊢ (stoneCechObj X ⟶ Y) ≃ (X ⟶ ↑Y.toTop)

Tactic:
haveI : DiscreteTopology X := ⟨rfl⟩

Goal state after:
X : Type u
Y : Stonean
this✝ : TopologicalSpace X := ⊥
this : DiscreteTopology X
⊢ (stoneCechObj X ⟶ Y) ≃ (X ⟶ ↑Y.toTop)
Module: Mathlib.Topology.CWComplex.Classical.Basic

Goal state before:
pp: X : Type u_1
t : TopologicalSpace X
C D : Set X
inst✝¹ : T2Space X
inst✝ : RelCWComplex C D
n : ℕ∞
x : X
⊢ ∀ (m : ℕ), ↑m < n + 1 ↔ ↑m ≤ n

Tactic:
intro m

Goal state after:
X : Type u_1
t : TopologicalSpace X
C D : Set X
inst✝¹ : T2Space X
inst✝ : RelCWComplex C D
n : ℕ∞
x : X
m : ℕ
⊢ ↑m < n + 1 ↔ ↑m ≤ n
Module: Mathlib.Topology.Compactness.CompactSystem

Goal state before:
pp: case neg
α : Type u_1
S : Set (Set α)
hpi : IsPiSystem S
h : ∀ (C : ℕ → Set α), Directed (fun x1 x2 ↦ x1 ⊇ x2) C → (∀ (i : ℕ), C i ∈ S) → ⋂ i, C i = ∅ → ∃ n, C n = ∅
C : ℕ → Set α
h1 : ∀ (i : ℕ), C i ∈ insert ∅ S
h2 : ⋂ n, ⋂ m, ⋂ (_ : m ≤ n), C m = ∅
n : ℕ
g : ¬(dissipate C n).Nonempty
⊢ dissipate C n ∈ S ∨ dissipate C n = ∅

Tactic:
· exact .inr (Set.not_nonempty_iff_eq_empty.mp g)

Goal state after:
Module: Mathlib.Topology.Connected.CardComponents

Goal state before:
pp: case inr
X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
f : X → Y
hf₁ : IsOpenMap f
hf₂ : IsClosedMap f
inst✝ : ConnectedSpace Y
y : Y
h :
  ∀ {n : ℕ} (U : Fin n → Set X),
    (∀ (i : Fin n), IsClopen (U i)) →
      (∀ (i : Fin n), (U i).Nonempty) → Pairwise (Disjoint on U) → ⋃ i, U i = Set.univ → ↑n ≤ (f ⁻¹' {y}).encard
hy : Infinite (ConnectedComponents X)
⊢ ∀ (m : ℕ), ↑m ≤ (f ⁻¹' {y}).encard

Tactic:
intro m

Goal state after:
case inr
X : Type u_1
Y : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
f : X → Y
hf₁ : IsOpenMap f
hf₂ : IsClosedMap f
inst✝ : ConnectedSpace Y
y : Y
h :
  ∀ {n : ℕ} (U : Fin n → Set X),
    (∀ (i : Fin n), IsClopen (U i)) →
      (∀ (i : Fin n), (U i).Nonempty) → Pairwise (Disjoint on U) → ⋃ i, U i = Set.univ → ↑n ≤ (f ⁻¹' {y}).encard
hy : Infinite (ConnectedComponents X)
m : ℕ
⊢ ↑m ≤ (f ⁻¹' {y}).encard
Module: Mathlib.Topology.ContinuousMap.Bounded.ArzelaAscoli

Goal state before:
pp: case refine_1
α : Type u
β : Type v
inst✝³ : TopologicalSpace α
inst✝² : CompactSpace α
inst✝¹ : PseudoMetricSpace β
inst✝ : CompactSpace β
A : Set (α →ᵇ β)
closed : IsClosed A
H : ∀ (x₀ : α), ∀ ε > 0, ∃ U ∈ nhds x₀, ∀ x ∈ U, ∀ x' ∈ U, ∀ (i : ↑A), dist (↑i x) (↑i x') < ε
ε : ℝ
ε0 : ε > 0
ε₁ : ℝ
ε₁0 : 0 < ε₁
εε₁ : ε₁ < ε
ε₂ : ℝ := ε₁ / 2 / 2
ε₂0 : ε₂ > 0
U : α → Set α
hU : ∀ (x : α), x ∈ U x ∧ IsOpen (U x) ∧ ∀ y ∈ U x, ∀ z ∈ U x, ∀ {f : α →ᵇ β}, f ∈ A → dist (f y) (f z) < ε₂
tα : Set α
left✝¹ : tα ⊆ univ
hfin✝ : tα.Finite
htα : univ ⊆ ⋃ x ∈ tα, U x
val✝¹ : Fintype ↑tα
tβ : Set β
left✝ : tβ ⊆ univ
hfin : tβ.Finite
htβ : univ ⊆ ⋃ y ∈ tβ, ball y ε₂
val✝ : Fintype ↑tβ
F : β → β
hF : ∀ (y : β), F y ∈ tβ ∧ dist y (F y) < ε₂
f : α →ᵇ β
hf : f ∈ A
g : α →ᵇ β
hg : g ∈ A
f_eq_g : (fun f a ↦ ⟨F (↑f ↑a), ⋯⟩) ⟨f, hf⟩ = (fun f a ↦ ⟨F (↑f ↑a), ⋯⟩) ⟨g, hg⟩
x x' : α
x'tα : x' ∈ tα
hx' : x ∈ U x'
⊢ dist (f x) (f x') < ε₂

Tactic:
exact (hU x').2.2 _ hx' _ (hU x').1 hf

Goal state after:
Module: Mathlib.Topology.Category.Profinite.Nobeling.Successor

Goal state before:
pp: I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x1 x2 ↦ x1 < x2
h₁ : ⊤ ≤ Submodule.span ℤ (Set.range (eval (π C fun x ↦ ord I x < o)))
⊢ Function.Injective (MaxToGood C hC hsC ho h₁)

Tactic:
intro m

Goal state after:
I : Type u
C : Set (I → Bool)
inst✝¹ : LinearOrder I
inst✝ : WellFoundedLT I
o : Ordinal.{u}
hC : IsClosed C
hsC : contained C (Order.succ o)
ho : o < Ordinal.type fun x1 x2 ↦ x1 < x2
h₁ : ⊤ ≤ Submodule.span ℤ (Set.range (eval (π C fun x ↦ ord I x < o)))
m : ↑(MaxProducts C ho)
⊢ ∀ ⦃a₂ : ↑(MaxProducts C ho)⦄, MaxToGood C hC hsC ho h₁ m = MaxToGood C hC hsC ho h₁ a₂ → m = a₂
Module: Mathlib.Topology.Filter

Goal state before:
pp: α : Type u_2
x : α
⊢ 𝓝 (𝓟 {x}) = 𝓟 {⊥, 𝓟 {x}}

Tactic:
nhds_principal,

Goal state after:
α : Type u_2
x : α
⊢ 𝓟 (Iic (𝓟 {x})) = 𝓟 {⊥, 𝓟 {x}}
Module: Mathlib.Topology.EMetricSpace.Weak

Goal state before:
pp: case none.some
α✝ : Type u
t✝ : TopologicalSpace α✝
m✝ : WeakPseudoEMetricSpace α✝
α : Type u
t : TopologicalSpace α
inst✝ : TopologicalSpace (Option α)
m : WeakEMetricSpace α
inst : EDist (Option α)
h_edist : inst = toEDist
h : IsOpenEmbedding some
val✝ : α
xy : edist none (some val✝) = 0
⊢ none = some val✝

Tactic:
simp at xy

Goal state after:
Module: Mathlib.Topology.EMetricSpace.Weak

Goal state before:
pp: case some.none
α✝ : Type u
t✝ : TopologicalSpace α✝
m✝ : WeakPseudoEMetricSpace α✝
α : Type u
t : TopologicalSpace α
inst✝ : TopologicalSpace (Option α)
m : WeakEMetricSpace α
inst : EDist (Option α)
h_edist : inst = toEDist
h : IsOpenEmbedding some
val✝ : α
xy : edist (some val✝) none = 0
⊢ some val✝ = none

Tactic:
simp at xy

Goal state after:
Module: Mathlib.Topology.EMetricSpace.Weak

Goal state before:
pp: case some.some
α✝ : Type u
t✝ : TopologicalSpace α✝
m✝ : WeakPseudoEMetricSpace α✝
α : Type u
t : TopologicalSpace α
inst✝ : TopologicalSpace (Option α)
m : WeakEMetricSpace α
inst : EDist (Option α)
h_edist : inst = toEDist
h : IsOpenEmbedding some
val✝¹ val✝ : α
xy : edist (some val✝¹) (some val✝) = 0
⊢ some val✝¹ = some val✝

Tactic:
m.eq_of_edist_eq_zero xy

Goal state after:
case some.some
α✝ : Type u
t✝ : TopologicalSpace α✝
m✝ : WeakPseudoEMetricSpace α✝
α : Type u
t : TopologicalSpace α
inst✝ : TopologicalSpace (Option α)
m : WeakEMetricSpace α
inst : EDist (Option α)
h_edist : inst = toEDist
h : IsOpenEmbedding some
val✝¹ val✝ : α
xy : edist (some val✝¹) (some val✝) = 0
⊢ some val✝ = some val✝
Module: Mathlib.Topology.Homotopy.HomotopyGroup

Goal state before:
pp: case inr
N : Type u_1
X : Type u_2
inst✝¹ : TopologicalSpace X
x : X
inst✝ : DecidableEq N
i : N
p : Ω (↑(Ω^ { j // j ≠ i } X x)) const
y : N → ↑I
j : N
Hj : y j = 0 ∨ y j = 1
Hne : j ≠ i
⊢ (↑(p.toContinuousMap (y i)) fun j ↦ y ↑j) = x

Tactic:
· exact GenLoop.boundary _ _ ⟨⟨j, Hne⟩, Hj⟩

Goal state after:
Module: Mathlib.Topology.Homotopy.HomotopyGroup

Goal state before:
pp: case refine_1.a
N : Type u_1
X : Type u_2
inst✝¹ : TopologicalSpace X
x : X
inst✝ : DecidableEq N
i✝ : N
p q : ↑(Ω^ N X x)
H : (↑p).HomotopyRel (↑q) (Cube.boundary N)
t : ↑I × ↑I
y : { j // j ≠ i✝ } → ↑I
i : { j // j ≠ i✝ }
iH : y i = 0 ∨ y i = 1
⊢ (Cube.insertAt i✝) (t.2, y) ∈ Cube.boundary N

Tactic:
apply Cube.insertAt_boundary; right; exact ⟨i, iH⟩

Goal state after:
Module: Mathlib.Topology.Homotopy.HomotopyGroup

Goal state before:
pp: case refine_1.hx
N : Type u_1
X : Type u_2
inst✝¹ : TopologicalSpace X
x : X
inst✝ : DecidableEq N
i✝ : N
p q : ↑(Ω^ N X x)
H : (↑p).HomotopyRel (↑q) (Cube.boundary N)
t : ↑I × ↑I
y : { j // j ≠ i✝ } → ↑I
i : { j // j ≠ i✝ }
iH : y i = 0 ∨ y i = 1
⊢ (Cube.insertAt i✝) (t.2, y) ∈ Cube.boundary N

Tactic:
apply Cube.insertAt_boundary; right; exact ⟨i, iH⟩

Goal state after:
Module: Mathlib.Topology.IsClosedRestrict

Goal state before:
pp: case mpr
ι : Type u_1
α : ι → Type u_2
s : Set ((i : ι) → α i)
S : Set ι
inst✝ : (i : ι) → TopologicalSpace (α i)
x : (i : ↑S) → α ↑i
z : (a : ι) → α a
hz_mem : z ∈ s
hzx : S.domRestrict z = x
⊢ ∃ a,
    (∃ x ∈ s, Sᶜ.domRestrict x = a) ∧
      ∃ a_1 ∈ s, ((∃ x ∈ s, Sᶜ.domRestrict x = Sᶜ.domRestrict a_1) ∧ Sᶜ.domRestrict a_1 = a) ∧ (fun i ↦ a_1 ↑i) = x

Tactic:
exact ⟨Sᶜ.domRestrict z, mem_image_of_mem Sᶜ.domRestrict hz_mem, z, hz_mem,
      ⟨⟨⟨z, hz_mem, rfl⟩, rfl⟩, hzx⟩⟩

Goal state after:
Module: Mathlib.Topology.List

Goal state before:
pp: case refine_1
α : Type u_1
inst✝ : TopologicalSpace α
as l : List α
⊢ pure l ≤ traverse 𝓝 l

Tactic:
induction l with
    | nil => exact le_rfl
    | cons a l ih =>
      suffices List.cons <$> pure a <*> pure l ≤ List.cons <$> 𝓝 a <*> traverse 𝓝 l by
        simpa only [functor_norm] using! this
      exact Filter.seq_mono (Filter.map_mono <| pure_le_nhds a) ih

Goal state after:
Module: Mathlib.Topology.List

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
n : ℕ
a : α
l : List α
⊢ Tendsto (fun p ↦ (p.1 :: p.2).eraseIdx (n + 1)) (𝓝 a ×ˢ 𝓝 l) (𝓝 ((a :: l).eraseIdx (n + 1)))

Tactic:
dsimp [eraseIdx]

Goal state after:
α : Type u_1
inst✝ : TopologicalSpace α
n : ℕ
a : α
l : List α
⊢ Tendsto (fun p ↦ p.1 :: p.2.eraseIdx n) (𝓝 a ×ˢ 𝓝 l) (𝓝 (a :: l.eraseIdx n))
Module: Mathlib.Topology.MetricSpace.Kuratowski

Goal state before:
pp: case inr.refine_1
α : Type u
inst✝ : PseudoMetricSpace α
s : Set α
ι : Type u_1
f : α → ↥(lp (fun x ↦ ℝ) ∞)
K : ℝ≥0
hfl : ∀ (i : ι), LipschitzOnWith K (fun a ↦ ↑(f a) i) s
g : ι → α → ℝ
hgl : ∀ (i : ι), LipschitzWith K (g i)
hgeq : ∀ (i : ι), EqOn (fun x ↦ ↑(f x) i) (g i) s
a₀ : α
ha₀_in_s : a₀ ∈ s
hf_extb : ∀ (a : α), Memℓp (swap g a) ∞
f_ext' : α → ↥(lp (fun x ↦ ℝ) ∞) := fun i ↦ ⟨swap g i, ⋯⟩
⊢ LipschitzWith K f_ext'

Tactic:
rw [LipschitzWith.coordinate]

Goal state after:
case inr.refine_1
α : Type u
inst✝ : PseudoMetricSpace α
s : Set α
ι : Type u_1
f : α → ↥(lp (fun x ↦ ℝ) ∞)
K : ℝ≥0
hfl : ∀ (i : ι), LipschitzOnWith K (fun a ↦ ↑(f a) i) s
g : ι → α → ℝ
hgl : ∀ (i : ι), LipschitzWith K (g i)
hgeq : ∀ (i : ι), EqOn (fun x ↦ ↑(f x) i) (g i) s
a₀ : α
ha₀_in_s : a₀ ∈ s
hf_extb : ∀ (a : α), Memℓp (swap g a) ∞
f_ext' : α → ↥(lp (fun x ↦ ℝ) ∞) := fun i ↦ ⟨swap g i, ⋯⟩
⊢ ∀ (i : ι), LipschitzWith K fun a ↦ ↑(f_ext' a) i
Module: Mathlib.Topology.MetricSpace.Closeds

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝² : EMetricSpace α
inst✝¹ : EMetricSpace β
s✝ : Set α
inst✝ : CompleteSpace α
B : ℕ → ℝ≥0∞ := fun n ↦ 2⁻¹ ^ n
B_pos : ∀ (n : ℕ), 0 < B n
B_ne_top : ∀ (n : ℕ), B n ≠ ∞
s : ℕ → Closeds α
hs : ∀ (N n m : ℕ), N ≤ n → N ≤ m → edist (s n) (s m) < B N
t0 : Set α := ⋂ n, closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (⋃ m, ⋃ (_ : m ≥ n), ↑(s m))
t : Closeds α := { carrier := t0, isClosed' := ⋯ }
n : ℕ
x : α
hx : x ∈ s n
⊢ ∃ y ∈ t0, edist x y ≤ 2 * B n

Tactic:
obtain ⟨z, hz₀, hz⟩ :
      ∃ z : ∀ l, s (n + l), (z 0 : α) = x ∧ ∀ k, edist (z k : α) (z (k + 1) : α) ≤ B n / 2 ^ k := by
      -- We prove existence of the sequence by induction.
      have : ∀ (l) (z : s (n + l)), ∃ z' : s (n + l + 1), edist (z : α) z' ≤ B n / 2 ^ l := by
        intro l z
        obtain ⟨z', z'_mem, hz'⟩ : ∃ z' ∈ s (n + l + 1), edist (z : α) z' < B n / 2 ^ l := by
          refine exists_edist_lt_of_hausdorffEDist_lt (s := s (n + l)) z.2 ?_
          simp only [ENNReal.inv_pow, div_eq_mul_inv]
          rw [← pow_add]
          apply hs <;> simp
        exact ⟨⟨z', z'_mem⟩, le_of_lt hz'⟩
      use fun k => Nat.recOn k ⟨x, hx⟩ fun l z => (this l z).choose
      simp only [Nat.add_zero, Nat.rec_zero, true_and]
      exact fun k => (this k _).choose_spec

Goal state after:
α : Type u_1
β : Type u_2
inst✝² : EMetricSpace α
inst✝¹ : EMetricSpace β
s✝ : Set α
inst✝ : CompleteSpace α
B : ℕ → ℝ≥0∞ := fun n ↦ 2⁻¹ ^ n
B_pos : ∀ (n : ℕ), 0 < B n
B_ne_top : ∀ (n : ℕ), B n ≠ ∞
s : ℕ → Closeds α
hs : ∀ (N n m : ℕ), N ≤ n → N ≤ m → edist (s n) (s m) < B N
t0 : Set α := ⋂ n, closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (⋃ m, ⋃ (_ : m ≥ n), ↑(s m))
t : Closeds α := { carrier := t0, isClosed' := ⋯ }
n : ℕ
x : α
hx : x ∈ s n
z : (l : ℕ) → ↥(s (n + l))
hz₀ : ↑(z 0) = x
hz : ∀ (k : ℕ), edist ↑(z k) ↑(z (k + 1)) ≤ B n / 2 ^ k
⊢ ∃ y ∈ t0, edist x y ≤ 2 * B n
Module: Mathlib.Topology.MetricSpace.Closeds

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝² : EMetricSpace α
inst✝¹ : EMetricSpace β
s✝ : Set α
inst✝ : CompleteSpace α
B : ℕ → ℝ≥0∞ := fun n ↦ 2⁻¹ ^ n
B_pos : ∀ (n : ℕ), 0 < B n
B_ne_top : ∀ (n : ℕ), B n ≠ ∞
s : ℕ → Closeds α
hs : ∀ (N n m : ℕ), N ≤ n → N ≤ m → edist (s n) (s m) < B N
t0 : Set α := ⋂ n, closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (⋃ m, ⋃ (_ : m ≥ n), ↑(s m))
t : Closeds α := { carrier := t0, isClosed' := ⋯ }
I1 : ∀ (n : ℕ), ∀ x ∈ s n, ∃ y ∈ t0, edist x y ≤ 2 * B n
n : ℕ
x : α
xt0 : x ∈ t0
this : x ∈ closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (⋃ m, ⋃ (_ : m ≥ n), ↑(s m))
⊢ ∃ y ∈ s n, edist x y ≤ 2 * B n

Tactic:
obtain ⟨z : α, hz, Dxz : edist x z < B n⟩ := EMetric.mem_closure_iff.1 this (B n) (B_pos n)

Goal state after:
α : Type u_1
β : Type u_2
inst✝² : EMetricSpace α
inst✝¹ : EMetricSpace β
s✝ : Set α
inst✝ : CompleteSpace α
B : ℕ → ℝ≥0∞ := fun n ↦ 2⁻¹ ^ n
B_pos : ∀ (n : ℕ), 0 < B n
B_ne_top : ∀ (n : ℕ), B n ≠ ∞
s : ℕ → Closeds α
hs : ∀ (N n m : ℕ), N ≤ n → N ≤ m → edist (s n) (s m) < B N
t0 : Set α := ⋂ n, closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (⋃ m, ⋃ (_ : m ≥ n), ↑(s m))
t : Closeds α := { carrier := t0, isClosed' := ⋯ }
I1 : ∀ (n : ℕ), ∀ x ∈ s n, ∃ y ∈ t0, edist x y ≤ 2 * B n
n : ℕ
x : α
xt0 : x ∈ t0
this : x ∈ closure[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (⋃ m, ⋃ (_ : m ≥ n), ↑(s m))
z : α
hz : z ∈ ⋃ m, ⋃ (_ : m ≥ n), ↑(s m)
Dxz : edist x z < B n
⊢ ∃ y ∈ s n, edist x y ≤ 2 * B n
Module: Mathlib.Topology.MetricSpace.GromovHausdorffRealized

Goal state before:
pp: X : Type u
Y : Type v
inst✝¹ : MetricSpace X
inst✝ : MetricSpace Y
I1 : ∀ (x y : X), IsClosed {f | f (inl x, inl y) = dist x y}
I2 : ∀ (x y : Y), IsClosed {f | f (inr x, inr y) = dist x y}
I3 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) = f (y, x)}
I4 : ∀ (x y z : X ⊕ Y), IsClosed {f | f (x, z) ≤ f (x, y) + f (y, z)}
I5 : ∀ (x : X ⊕ Y), IsClosed {f | f (x, x) = 0}
I6 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) ≤ ↑(maxVar X Y)}
this :
  candidatesB X Y =
    (((((⋂ x, ⋂ y, {f | f (inl x, inl y) = dist x y}) ∩ ⋂ x, ⋂ y, {f | f (inr x, inr y) = dist x y}) ∩
            ⋂ x, ⋂ y, {f | f (x, y) = f (y, x)}) ∩
          ⋂ x, ⋂ y, ⋂ z, {f | f (x, z) ≤ f (x, y) + f (y, z)}) ∩
        ⋂ x, {f | f (x, x) = 0}) ∩
      ⋂ x, ⋂ y, {f | f (x, y) ≤ ↑(maxVar X Y)}
⊢ IsClosed (⋂ x, ⋂ y, {f | f (inl x, inl y) = dist x y})

Tactic:
apply isClosed_iInter _

Goal state after:
X : Type u
Y : Type v
inst✝¹ : MetricSpace X
inst✝ : MetricSpace Y
I1 : ∀ (x y : X), IsClosed {f | f (inl x, inl y) = dist x y}
I2 : ∀ (x y : Y), IsClosed {f | f (inr x, inr y) = dist x y}
I3 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) = f (y, x)}
I4 : ∀ (x y z : X ⊕ Y), IsClosed {f | f (x, z) ≤ f (x, y) + f (y, z)}
I5 : ∀ (x : X ⊕ Y), IsClosed {f | f (x, x) = 0}
I6 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) ≤ ↑(maxVar X Y)}
this :
  candidatesB X Y =
    (((((⋂ x, ⋂ y, {f | f (inl x, inl y) = dist x y}) ∩ ⋂ x, ⋂ y, {f | f (inr x, inr y) = dist x y}) ∩
            ⋂ x, ⋂ y, {f | f (x, y) = f (y, x)}) ∩
          ⋂ x, ⋂ y, ⋂ z, {f | f (x, z) ≤ f (x, y) + f (y, z)}) ∩
        ⋂ x, {f | f (x, x) = 0}) ∩
      ⋂ x, ⋂ y, {f | f (x, y) ≤ ↑(maxVar X Y)}
⊢ ∀ (i : X), IsClosed (⋂ y, {f | f (inl i, inl y) = dist i y})
Module: Mathlib.Topology.MetricSpace.Infsep

Goal state before:
pp: α : Type u_1
inst✝ : EDist α
s : Set α
hs : 0 < s.infsep
⊢ s.Nontrivial

Tactic:
contrapose hs
  rw [not_nontrivial_iff] at hs
  exact hs.infsep_zero ▸ lt_irrefl _

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

Goal state before:
pp: X : Type u
Y : Type v
inst✝¹ : MetricSpace X
inst✝ : MetricSpace Y
I1 : ∀ (x y : X), IsClosed {f | f (inl x, inl y) = dist x y}
I2 : ∀ (x y : Y), IsClosed {f | f (inr x, inr y) = dist x y}
I3 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) = f (y, x)}
I4 : ∀ (x y z : X ⊕ Y), IsClosed {f | f (x, z) ≤ f (x, y) + f (y, z)}
I5 : ∀ (x : X ⊕ Y), IsClosed {f | f (x, x) = 0}
I6 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) ≤ ↑(maxVar X Y)}
this :
  candidatesB X Y =
    (((((⋂ x, ⋂ y, {f | f (inl x, inl y) = dist x y}) ∩ ⋂ x, ⋂ y, {f | f (inr x, inr y) = dist x y}) ∩
            ⋂ x, ⋂ y, {f | f (x, y) = f (y, x)}) ∩
          ⋂ x, ⋂ y, ⋂ z, {f | f (x, z) ≤ f (x, y) + f (y, z)}) ∩
        ⋂ x, {f | f (x, x) = 0}) ∩
      ⋂ x, ⋂ y, {f | f (x, y) ≤ ↑(maxVar X Y)}
⊢ ∀ (i : X), IsClosed (⋂ y, {f | f (inl i, inl y) = dist i y})

Tactic:
apply isClosed_iInter _

Goal state after:
X : Type u
Y : Type v
inst✝¹ : MetricSpace X
inst✝ : MetricSpace Y
I1 : ∀ (x y : X), IsClosed {f | f (inl x, inl y) = dist x y}
I2 : ∀ (x y : Y), IsClosed {f | f (inr x, inr y) = dist x y}
I3 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) = f (y, x)}
I4 : ∀ (x y z : X ⊕ Y), IsClosed {f | f (x, z) ≤ f (x, y) + f (y, z)}
I5 : ∀ (x : X ⊕ Y), IsClosed {f | f (x, x) = 0}
I6 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) ≤ ↑(maxVar X Y)}
this :
  candidatesB X Y =
    (((((⋂ x, ⋂ y, {f | f (inl x, inl y) = dist x y}) ∩ ⋂ x, ⋂ y, {f | f (inr x, inr y) = dist x y}) ∩
            ⋂ x, ⋂ y, {f | f (x, y) = f (y, x)}) ∩
          ⋂ x, ⋂ y, ⋂ z, {f | f (x, z) ≤ f (x, y) + f (y, z)}) ∩
        ⋂ x, {f | f (x, x) = 0}) ∩
      ⋂ x, ⋂ y, {f | f (x, y) ≤ ↑(maxVar X Y)}
⊢ ∀ (i : X), IsClosed (⋂ y, {f | f (inl i, inl y) = dist i y})
Module: Mathlib.Topology.MetricSpace.Ultra.TotallySeparated

Goal state before:
pp: case refine_2
X : Type u_1
inst✝¹ : MetricSpace X
inst✝ : IsUltrametricDist X
x y : X
h : x ≠ y
r : ℝ
hr : 0 < r
hr' : r < dist x y
⊢ y ∈ (ball x r)ᶜ

Tactic:
· 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
s : Set (Snowflaking X α hα₀ hα₁)
⊢ ediam (⇑ofSnowflaking '' s) = ediam s ^ α⁻¹

Tactic:
refine eq_of_forall_ge_iff fun c ↦ ?_

Goal state after:
X : Type u_1
α : ℝ
hα₀ : 0 < α
hα₁ : α ≤ 1
inst✝ : PseudoEMetricSpace X
s : Set (Snowflaking X α hα₀ hα₁)
c : ℝ≥0∞
⊢ ediam (⇑ofSnowflaking '' s) ≤ c ↔ ediam s ^ α⁻¹ ≤ c
Module: Mathlib.Topology.MetricSpace.GromovHausdorffRealized

Goal state before:
pp: X : Type u
Y : Type v
inst✝¹ : MetricSpace X
inst✝ : MetricSpace Y
I1 : ∀ (x y : X), IsClosed {f | f (inl x, inl y) = dist x y}
I2 : ∀ (x y : Y), IsClosed {f | f (inr x, inr y) = dist x y}
I3 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) = f (y, x)}
I4 : ∀ (x y z : X ⊕ Y), IsClosed {f | f (x, z) ≤ f (x, y) + f (y, z)}
I5 : ∀ (x : X ⊕ Y), IsClosed {f | f (x, x) = 0}
I6 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) ≤ ↑(maxVar X Y)}
this :
  candidatesB X Y =
    (((((⋂ x, ⋂ y, {f | f (inl x, inl y) = dist x y}) ∩ ⋂ x, ⋂ y, {f | f (inr x, inr y) = dist x y}) ∩
            ⋂ x, ⋂ y, {f | f (x, y) = f (y, x)}) ∩
          ⋂ x, ⋂ y, ⋂ z, {f | f (x, z) ≤ f (x, y) + f (y, z)}) ∩
        ⋂ x, {f | f (x, x) = 0}) ∩
      ⋂ x, ⋂ y, {f | f (x, y) ≤ ↑(maxVar X Y)}
x : X
⊢ IsClosed (⋂ y, {f | f (inl x, inl y) = dist x y})

Tactic:
apply isClosed_iInter _

Goal state after:
X : Type u
Y : Type v
inst✝¹ : MetricSpace X
inst✝ : MetricSpace Y
I1 : ∀ (x y : X), IsClosed {f | f (inl x, inl y) = dist x y}
I2 : ∀ (x y : Y), IsClosed {f | f (inr x, inr y) = dist x y}
I3 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) = f (y, x)}
I4 : ∀ (x y z : X ⊕ Y), IsClosed {f | f (x, z) ≤ f (x, y) + f (y, z)}
I5 : ∀ (x : X ⊕ Y), IsClosed {f | f (x, x) = 0}
I6 : ∀ (x y : X ⊕ Y), IsClosed {f | f (x, y) ≤ ↑(maxVar X Y)}
this :
  candidatesB X Y =
    (((((⋂ x, ⋂ y, {f | f (inl x, inl y) = dist x y}) ∩ ⋂ x, ⋂ y, {f | f (inr x, inr y) = dist x y}) ∩
            ⋂ x, ⋂ y, {f | f (x, y) = f (y, x)}) ∩
          ⋂ x, ⋂ y, ⋂ z, {f | f (x, z) ≤ f (x, y) + f (y, z)}) ∩
        ⋂ x, {f | f (x, x) = 0}) ∩
      ⋂ x, ⋂ y, {f | f (x, y) ≤ ↑(maxVar X Y)}
x : X
⊢ ∀ (i : X), IsClosed {f | f (inl x, inl i) = dist x i}