mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Topology.Homotopy.HomotopyGroup

Goal state before:
pp: case pos
N : Type u_1
X : Type u_2
inst✝¹ : TopologicalSpace X
x : X
inst✝ : DecidableEq N
i j : N
h : i = j
⊢ auxGroup i = auxGroup j

Tactic:
h

Goal state after:
case pos
N : Type u_1
X : Type u_2
inst✝¹ : TopologicalSpace X
x : X
inst✝ : DecidableEq N
i j : N
h : i = j
⊢ auxGroup j = auxGroup j
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
l : ℕ
⊢ ∀ (z : ↥(s (n + l))), ∃ z', edist ↑z ↑z' ≤ B n / 2 ^ l

Tactic:
z

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
l : ℕ
z : ↥(s (n + l))
⊢ ∃ z', edist ↑z ↑z' ≤ B n / 2 ^ l
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 (x n) + dist (x n) b = 2 * dist a (x n) + (dist b (x n) - dist a (x n))

Tactic:
by simp [dist_comm]; ring

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
f : ProdSpaceFun X Y
x y z t : X ⊕ Y
fA : f ∈ candidates X Y
⊢ f (x, z) + f (t, y) ≤ ↑(maxVar X Y) * dist x z + ↑(maxVar X Y) * dist t y

Tactic:
by
      gcongr <;> apply candidates_dist_bound fA

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

Goal state before:
pp: α : Type u
inst✝ : PseudoMetricSpace α
s : Set α
ι : Type u_1
f : α → ↥(lp (fun x ↦ ℝ) ∞)
K : ℝ≥0
hfl : LipschitzOnWith K f s
⊢ ∃ g, LipschitzWith K g ∧ EqOn f g s

Tactic:
rw [LipschitzOnWith.coordinate] at hfl
  have (i : ι) : ∃ g : α → ℝ, LipschitzWith K g ∧ EqOn (fun x => f x i) g s :=
    LipschitzOnWith.extend_real (hfl i) -- use the nonlinear Hahn-Banach theorem here!
  choose g hgl hgeq using this
  rcases s.eq_empty_or_nonempty with rfl | ⟨a₀, ha₀_in_s⟩
  · exact ⟨0, LipschitzWith.const' 0, by simp⟩
  · -- Show that the extensions are uniformly bounded
    have hf_extb : ∀ a : α, Memℓp (swap g a) ∞ := by
      apply LipschitzWith.uniformly_bounded (swap g) hgl a₀
      use ‖f a₀‖
      rintro - ⟨i, rfl⟩
      simp_rw [← hgeq i ha₀_in_s]
      exact lp.norm_apply_le_norm top_ne_zero (f a₀) i
    -- Construct witness by bundling the function with its certificate of membership in ℓ^∞
    let f_ext' : α → ℓ^∞(ι, ℝ) := fun i ↦ ⟨swap g i, hf_extb i⟩
    refine ⟨f_ext', ?_, ?_⟩
    · rw [LipschitzWith.coordinate]
      exact hgl
    · intro a hyp
      ext i
      exact (hgeq i) hyp

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

Goal state before:
pp: α : Type u_1
inst✝ : EDist α
s : Set α
⊢ s.einfsep ≠ ∞ ↔ ∃ x ∈ s, ∃ y ∈ s, x ≠ y ∧ edist x y ≠ ∞

Tactic:
simp_rw [← lt_top_iff_ne_top, einfsep_lt_top]

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

Goal state before:
pp: X : Type u_1
Y : Type u_2
inst✝¹ : MetricSpace X
inst✝ : EMetricSpace Y
C r : ℝ≥0
f : X → Y
hf : HolderWith C r f
⊢ ↑(nnHolderNorm r f) ≤ ↑C

Tactic:
hf.memHolder.coe_nnHolderNorm_eq_eHolderNorm

Goal state after:
X : Type u_1
Y : Type u_2
inst✝¹ : MetricSpace X
inst✝ : EMetricSpace Y
C r : ℝ≥0
f : X → Y
hf : HolderWith C r f
⊢ eHolderNorm r f ≤ ↑C
Module: Mathlib.Topology.MetricSpace.Ultra.Pi

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
inst✝² : Fintype ι
inst✝¹ : (i : ι) → PseudoMetricSpace (X i)
inst✝ : ∀ (i : ι), IsUltrametricDist (X i)
f g : (i : ι) → X i
⊢ ∀ (z : (i : ι) → X i), dist f z ≤ max (dist f g) (dist g z)

Tactic:
h

Goal state after:
ι : Type u_1
X : ι → Type u_2
inst✝² : Fintype ι
inst✝¹ : (i : ι) → PseudoMetricSpace (X i)
inst✝ : ∀ (i : ι), IsUltrametricDist (X i)
f g h : (i : ι) → X i
⊢ dist f h ≤ max (dist f g) (dist g h)
Module: Mathlib.Topology.MetricSpace.Ultra.Pi

Goal state before:
pp: ι : Type u_1
X : ι → Type u_2
inst✝² : Fintype ι
inst✝¹ : (i : ι) → PseudoMetricSpace (X i)
inst✝ : ∀ (i : ι), IsUltrametricDist (X i)
⊢ IsUltrametricDist ((i : ι) → X i)

Tactic:
by
  constructor
  intro f g h
  simp only [dist_pi_def, ← NNReal.coe_max, NNReal.coe_le_coe, ← Finset.sup_sup]
  exact Finset.sup_mono_fun fun i _ ↦ IsUltrametricDist.dist_triangle_max (f i) (g i) (h i)

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 I4 _ _ _

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.NatEmbedding

Goal state before:
pp: X : Type u_1
inst✝² : TopologicalSpace X
inst✝¹ : T2Space X
inst✝ : Infinite X
x : X
hx : (𝓝[≠] x).NeBot
this : ∃ U, (∀ (n : ℕ), (U n).Nonempty ∧ IsOpen[inst✝²] (U n) ∧ (U n)ᶜ ∈ 𝓝 x) ∧ Pairwise (Disjoint on U)
⊢ ∃ U, (∀ (n : ℕ), (U n).Nonempty) ∧ (∀ (n : ℕ), IsOpen[inst✝²] (U n)) ∧ Pairwise (Disjoint on U)

Tactic:
rcases this with ⟨U, hU, hd⟩

Goal state after:
X : Type u_1
inst✝² : TopologicalSpace X
inst✝¹ : T2Space X
inst✝ : Infinite X
x : X
hx : (𝓝[≠] x).NeBot
U : ℕ → Set X
hU : ∀ (n : ℕ), (U n).Nonempty ∧ IsOpen[inst✝²] (U n) ∧ (U n)ᶜ ∈ 𝓝 x
hd : Pairwise (Disjoint on U)
⊢ ∃ U, (∀ (n : ℕ), (U n).Nonempty) ∧ (∀ (n : ℕ), IsOpen[inst✝²] (U n)) ∧ Pairwise (Disjoint on U)
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
⊢ ∀ (i : X), IsClosed {f | f (inl x, inl i) = dist x i}

Tactic:
apply I4 _ _ _

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}
Module: Mathlib.Topology.Order.LowerUpperTopology

Goal state before:
pp: case basic
α : Type u_1
inst✝² : Preorder α
inst✝¹ : TopologicalSpace α
inst✝ : IsLower α
s u : Set α
h' : u ∈ {t | ∃ a, (Ici a)ᶜ = t}
⊢ IsLowerSet u

Tactic:
| basic u h' =>

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

Goal state before:
pp: α : Type u_1
inst✝² : Preorder α
inst✝¹ : TopologicalSpace α
inst✝ : IsLower α
s : Set α
h : GenerateOpen {t | ∃ a, (Ici a)ᶜ = t} s
⊢ IsLowerSet s

Tactic:
induction h with

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

Goal state before:
pp: case mpr
α : Type u_1
β : Type u_2
inst✝⁵ : Preorder α
inst✝⁴ : Preorder β
inst✝³ : TopologicalSpace α
inst✝² : TopologicalSpace β
inst✝¹ : Topology.IsUpperSet α
inst✝ : Topology.IsUpperSet β
f : α → β
hf : Continuous[inst✝³, inst✝²] f
a b : α
hab : a ≤ b
⊢ f a ≤ f b

Tactic:
rw [← mem_Iic, ← closure_singleton] at hab ⊢

Goal state after:
case mpr
α : Type u_1
β : Type u_2
inst✝⁵ : Preorder α
inst✝⁴ : Preorder β
inst✝³ : TopologicalSpace α
inst✝² : TopologicalSpace β
inst✝¹ : Topology.IsUpperSet α
inst✝ : Topology.IsUpperSet β
f : α → β
hf : Continuous[inst✝³, inst✝²] f
a b : α
hab : a ∈ closure[inst✝³] {b}
⊢ f a ∈ closure[inst✝²] {f b}
Module: Mathlib.Topology.Order.LowerUpperTopology

Goal state before:
pp: α : Type u_1
β : Type u_2
inst✝⁵ : CompleteLattice α
inst✝⁴ : CompleteLattice β
inst✝³ : TopologicalSpace α
inst✝² : IsLower α
inst✝¹ : TopologicalSpace β
inst✝ : IsLower β
f : sInfHom α β
⊢ Continuous[inst✝³, inst✝¹] ⇑f

Tactic:
refine IsLower.continuous_iff_Ici.2 fun b => ?_
  convert! isClosed_Ici (a := sInf <| f ⁻¹' Ici b)
  refine Subset.antisymm (fun a => sInf_le) fun a ha => le_trans ?_ <|
    OrderHomClass.mono (f : α →o β) ha
  refine LE.le.trans ?_ (map_sInf f _).ge
  simp

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 : Y), IsClosed (⋂ y, {f | f (inr i, inr y) = dist i y})

Tactic:
apply I4 _ _ _

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 : Y), IsClosed (⋂ y, {f | f (inr i, inr y) = dist i y})
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 : Y
⊢ ∀ (i : Y), IsClosed {f | f (inr x, inr i) = dist x i}

Tactic:
apply I4 _ _ _

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 : Y
⊢ ∀ (i : Y), IsClosed {f | f (inr x, inr i) = dist x i}
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 ⊕ Y), IsClosed (⋂ y, {f | f (i, y) = f (y, i)})

Tactic:
apply I4 _ _ _

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 ⊕ Y), IsClosed (⋂ y, {f | f (i, y) = f (y, i)})
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
ht : (↑t₁ \ ↑t₂).Nonempty
hUVd : (U t₁ ∩ d ∩ V t₂).Nonempty
⊢ False

Tactic:
h

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).Nonempty
hUVd : (U t₂ ∩ d ∩ V t₂).Nonempty
⊢ False
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
⊢ 2 ^ #↑s ≤ 2 ^ #↑d

Tactic:
by
  have h_closed (t) (ht : t ∈ 𝒫 s) : IsClosed t := by
    rw [← inter_eq_self_of_subset_right ht, ← Subtype.image_preimage_val]
    exact hs.isClosedMap_subtype_val _ (isClosed_discrete _)
  choose U V hU hV hUs hVs hUV using fun t : 𝒫 s ↦
    normal_separation (h_closed t t.2) (h_closed _ sdiff_subset) disjoint_sdiff_right
  have hUd {t₁ t₂} (h : U t₁ ∩ d = U t₂ ∩ d) : t₁.1 ⊆ t₂.1 := by
    by_contra ht
    rw [← sdiff_nonempty] at ht
    have hUVd := hd.inter_open_nonempty _ ((hU t₁).inter (hV t₂)) <| ht.mono <|
      subset_inter (sdiff_subset.trans (hUs t₁)) ((sdiff_subset_sdiff_left t₁.2).trans (hVs t₂))
    rw [inter_right_comm, h] at hUVd
    exact hUVd.not_disjoint <| disjoint_of_subset_left inter_subset_left (hUV t₂)
  have h_inj : Injective (U · ∩ d) := fun _ _ h ↦ SetCoe.ext <| (hUd h).antisymm (hUd h.symm)
  rw [← mk_powerset, ← mk_powerset, ← mk_range_eq _ h_inj]
  apply mk_le_mk_of_subset
  rw [range_subset_iff]
  intro
  exact inter_subset_right

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)}
x : X ⊕ Y
⊢ ∀ (i : X ⊕ Y), IsClosed {f | f (x, i) = f (i, x)}

Tactic:
apply I4 _ _ _

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 ⊕ Y
⊢ ∀ (i : X ⊕ Y), IsClosed {f | f (x, i) = f (i, x)}
Module: Mathlib.Topology.Separation.PerfectlyNormal

Goal state before:
pp: X : Type u_1
inst✝ : TopologicalSpace X
h : PerfectlyNormalSpace X
s : Set X
hs : IsClosed[inst✝] s
U : ℕ → Set X
ho : ∀ (n : ℕ), IsOpen[inst✝] (U n)
hu : s = ⋂ n, U n
this : ∀ (n : ℕ), Disjoint s (U n)ᶜ
⊢ ∃ f, s = ⇑f ⁻¹' {0} ∧ ∀ (x : X), f x ∈ Icc 0 1

Tactic:
choose f hfs hfu hfr using fun n =>
      exists_continuous_zero_one_of_isClosed hs (ho n).isClosed_compl (this n)

Goal state after:
X : Type u_1
inst✝ : TopologicalSpace X
h : PerfectlyNormalSpace X
s : Set X
hs : IsClosed[inst✝] s
U : ℕ → Set X
ho : ∀ (n : ℕ), IsOpen[inst✝] (U n)
hu : s = ⋂ n, U n
this : ∀ (n : ℕ), Disjoint s (U n)ᶜ
f : ℕ → C(X, ℝ)
hfs : ∀ (n : ℕ), EqOn (⇑(f n)) 0 s
hfu : ∀ (n : ℕ), EqOn (⇑(f n)) 1 (U n)ᶜ
hfr : ∀ (n : ℕ) (x : X), (f n) x ∈ Icc 0 1
⊢ ∃ f, s = ⇑f ⁻¹' {0} ∧ ∀ (x : X), f x ∈ Icc 0 1
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 ⊕ Y), IsClosed (⋂ y, ⋂ z, {f | f (i, z) ≤ f (i, y) + f (y, z)})

Tactic:
apply I4 _ _ _

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 ⊕ Y), IsClosed (⋂ y, ⋂ z, {f | f (i, z) ≤ f (i, y) + f (y, z)})