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

Goal state before:
pp: α : Type u_1
inst✝⁵ : LinearOrder α
inst✝⁴ : TopologicalSpace α
inst✝³ : OrderTopology α
a b c : α
inst✝² : Fact (a ≤ b)
inst✝¹ : Fact (b ≤ c)
E : Type u_2
inst✝ : TopologicalSpace E
f : C(↑(Icc a b), E)
g : C(↑(Icc b c), E)
ι : Type u_3
p : Filter ι
F : ι → C(↑(Icc a b), E)
G : ι → C(↑(Icc b c), E)
hfg : ∀ᶠ (i : ι) in p, (F i) ⊤ = (G i) ⊥
hfg' : f ⊤ = g ⊥
hf :
  ∀ (K : Set ↑(Icc a b)),
    IsCompact K → ∀ (U : Set E), IsOpen[inst✝] U → MapsTo (⇑f) K U → ∀ᶠ (a_4 : ι) in p, MapsTo (⇑(F a_4)) K U
hg :
  ∀ (K : Set ↑(Icc b c)),
    IsCompact K → ∀ (U : Set E), IsOpen[inst✝] U → MapsTo (⇑g) K U → ∀ᶠ (a : ι) in p, MapsTo (⇑(G a)) K U
K : Set ↑(Icc a c)
hK : IsCompact K
U : Set E
hU : IsOpen[inst✝] U
hfgU : MapsTo (⇑(f.concat g)) K U
h : b ∈ Icc a c
K₁ : Set ↑(Icc a b) := ⇑projIccCM '' Subtype.val '' (K ∩ Iic ⟨b, h⟩)
K₂ : Set ↑(Icc b c) := ⇑projIccCM '' Subtype.val '' (K ∩ Ici ⟨b, h⟩)
hK₁ : IsCompact K₁
hK₂ : IsCompact K₂
⊢ ∀ᶠ (a_1 : ι) in p, MapsTo (⇑((F a_1).concat (G a_1))) K U

Tactic:
have hfU : MapsTo f K₁ U := by
    rw [← concat_comp_IccInclusionLeft hfg']
    apply hfgU.comp
    rintro x ⟨y, ⟨⟨z, hz⟩, ⟨h1, (h2 : z ≤ b)⟩, rfl⟩, rfl⟩
    simpa [projIccCM, projIcc, h2, hz.1] using! h1

Goal state after:
α : Type u_1
inst✝⁵ : LinearOrder α
inst✝⁴ : TopologicalSpace α
inst✝³ : OrderTopology α
a b c : α
inst✝² : Fact (a ≤ b)
inst✝¹ : Fact (b ≤ c)
E : Type u_2
inst✝ : TopologicalSpace E
f : C(↑(Icc a b), E)
g : C(↑(Icc b c), E)
ι : Type u_3
p : Filter ι
F : ι → C(↑(Icc a b), E)
G : ι → C(↑(Icc b c), E)
hfg : ∀ᶠ (i : ι) in p, (F i) ⊤ = (G i) ⊥
hfg' : f ⊤ = g ⊥
hf :
  ∀ (K : Set ↑(Icc a b)),
    IsCompact K → ∀ (U : Set E), IsOpen[inst✝] U → MapsTo (⇑f) K U → ∀ᶠ (a_4 : ι) in p, MapsTo (⇑(F a_4)) K U
hg :
  ∀ (K : Set ↑(Icc b c)),
    IsCompact K → ∀ (U : Set E), IsOpen[inst✝] U → MapsTo (⇑g) K U → ∀ᶠ (a : ι) in p, MapsTo (⇑(G a)) K U
K : Set ↑(Icc a c)
hK : IsCompact K
U : Set E
hU : IsOpen[inst✝] U
hfgU : MapsTo (⇑(f.concat g)) K U
h : b ∈ Icc a c
K₁ : Set ↑(Icc a b) := ⇑projIccCM '' Subtype.val '' (K ∩ Iic ⟨b, h⟩)
K₂ : Set ↑(Icc b c) := ⇑projIccCM '' Subtype.val '' (K ∩ Ici ⟨b, h⟩)
hK₁ : IsCompact K₁
hK₂ : IsCompact K₂
hfU : MapsTo (⇑f) K₁ U
⊢ ∀ᶠ (a_1 : ι) in p, MapsTo (⇑((F a_1).concat (G a_1))) K U
Module: Mathlib.Topology.Homotopy.HomotopyGroup

Goal state before:
pp: N : Type u_1
X : Type u_2
inst✝ : TopologicalSpace X
M : Type u_3
x : X
⊢ Continuous[_, inst✝]
    (Function.uncurry fun x_1 y ↦
      (((↑x_1.1).comp { toFun := sumArrowHomeomorphProdArrow.invFun, continuous_toFun := ⋯ }).curry.toFun x_1.2) y)

Tactic:
dsimp; fun_prop

Goal state after:
Module: Mathlib.Topology.IsClosedRestrict

Goal state before:
pp: ι : Type u_1
α✝ : ι → Type u_2
s✝ : Set ((i : ι) → α✝ i)
i : ι
S✝ : Set ι
α : ι → Type u_3
inst✝ : (i : ι) → TopologicalSpace (α i)
S : Set ι
s : Set ((j : ι) → α j)
⊢ Continuous[instTopologicalSpaceSubtype, instTopologicalSpaceProd] fun x ↦ (⟨Sᶜ.domRestrict ↑x, ⋯⟩, fun i ↦ ↑x ↑i)

Tactic:
by
    refine (Continuous.subtype_mk (by fun_prop) _).prodMk ?_
    rw [continuous_pi_iff]
    exact fun _ ↦ (continuous_apply _).comp continuous_subtype_val

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

Goal state before:
pp: T : Type u_1
inst✝² : PseudoEMetricSpace T
a c : ℝ≥0∞
J : Finset T
inst✝¹ : DecidableEq T
E : Type u_2
inst✝ : PseudoEMetricSpace E
ha : 1 < a
f : T → E
s : T
hs : s ∈ J
t : T
ht : t ∈ J
hst : edist ⟨s, hs⟩ ⟨t, ht⟩ ≤ c
hJ : J.Nonempty
P : ℕ → Prop := fun l ↦ s ∈ (logSizeBallSeq J hJ a c l).finset ∧ t ∈ (logSizeBallSeq J hJ a c l).finset
l : ℕ := Nat.findGreatest P (#J - 1)
hsV : s ∈ (logSizeBallSeq J hJ a c l).finset
htV : t ∈ (logSizeBallSeq J hJ a c l).finset
this :
  ∀ (s : T) (hs : s ∈ J) (t : T) (ht : t ∈ J) (hst : edist ⟨s, hs⟩ ⟨t, ht⟩ ≤ c),
    let P := fun l ↦ s ∈ (logSizeBallSeq J hJ a c l).finset ∧ t ∈ (logSizeBallSeq J hJ a c l).finset;
    let l := Nat.findGreatest P (#J - 1);
    s ∈ (logSizeBallSeq J hJ a c l).finset →
      t ∈ (logSizeBallSeq J hJ a c l).finset →
        s ∉ (logSizeBallSeq J hJ a c (l + 1)).finset →
          edist (f ↑⟨s, hs⟩) (f ↑↑⟨⟨t, ht⟩, hst⟩) ≤ 2 * ⨆ p, edist (f (↑p).1) (f (↑p).2)
h : ¬s ∉ (logSizeBallSeq J hJ a c (l + 1)).finset
hl : #J ≤ l + 1
⊢ Nat.findGreatest P (#J - 1) + 1 ≤ #J

Tactic:
grw [← Nat.sub_add_cancel <| Order.one_le_iff_pos.mpr (Finset.card_pos.mpr hJ),
            Nat.findGreatest_le]

Goal state after:
T : Type u_1
inst✝² : PseudoEMetricSpace T
a c : ℝ≥0∞
J : Finset T
inst✝¹ : DecidableEq T
E : Type u_2
inst✝ : PseudoEMetricSpace E
ha : 1 < a
f : T → E
s : T
hs : s ∈ J
t : T
ht : t ∈ J
hst : edist ⟨s, hs⟩ ⟨t, ht⟩ ≤ c
hJ : J.Nonempty
P : ℕ → Prop := fun l ↦ s ∈ (logSizeBallSeq J hJ a c l).finset ∧ t ∈ (logSizeBallSeq J hJ a c l).finset
l : ℕ := Nat.findGreatest P (#J - 1)
hsV : s ∈ (logSizeBallSeq J hJ a c l).finset
htV : t ∈ (logSizeBallSeq J hJ a c l).finset
this :
  ∀ (s : T) (hs : s ∈ J) (t : T) (ht : t ∈ J) (hst : edist ⟨s, hs⟩ ⟨t, ht⟩ ≤ c),
    let P := fun l ↦ s ∈ (logSizeBallSeq J hJ a c l).finset ∧ t ∈ (logSizeBallSeq J hJ a c l).finset;
    let l := Nat.findGreatest P (#J - 1);
    s ∈ (logSizeBallSeq J hJ a c l).finset →
      t ∈ (logSizeBallSeq J hJ a c l).finset →
        s ∉ (logSizeBallSeq J hJ a c (l + 1)).finset →
          edist (f ↑⟨s, hs⟩) (f ↑↑⟨⟨t, ht⟩, hst⟩) ≤ 2 * ⨆ p, edist (f (↑p).1) (f (↑p).2)
h : ¬s ∉ (logSizeBallSeq J hJ a c (l + 1)).finset
hl : #J ≤ l + 1
⊢ #J - 1 + 1 - 1 + 1 ≤ #J - 1 + 1
Module: Mathlib.Topology.Homotopy.HomotopyGroup

Goal state before:
pp: case refine_5
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 y : ↑I
⊢ y ∈ {0, 1} →
    {
          toFun := fun x_1 ↦
            { toFun := fun t ↦ ⟨(homotopyTo i H) t, ⋯⟩, continuous_toFun := ⋯, map_zero_left := ⋯,
                  map_one_left := ⋯ }.toFun
              (t, x_1),
          continuous_toFun := ⋯ }
        y =
      (toLoop i p).toContinuousMap y

Tactic:
yH

Goal state after:
case refine_5
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 y : ↑I
yH : y ∈ {0, 1}
⊢ {
        toFun := fun x_1 ↦
          { toFun := fun t ↦ ⟨(homotopyTo i H) t, ⋯⟩, continuous_toFun := ⋯, map_zero_left := ⋯,
                map_one_left := ⋯ }.toFun
            (t, x_1),
        continuous_toFun := ⋯ }
      y =
    (toLoop i p).toContinuousMap y
Module: Mathlib.Topology.Maps.Proper.UniversallyClosed

Goal state before:
pp: case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
𝒰 : Ultrafilter X
y : Y
hy : Tendsto f (↑𝒰) (nhds y)
F : Set (X × Filter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this✝ : IsClosed (Prod.map f id '' F)
this : (y, ↑𝒰) ∈ Prod.map f id '' F
⊢ ∃ x, f x = y ∧ ↑𝒰 ≤ nhds x

Tactic:
rcases this with ⟨⟨x, _⟩, hx, ⟨_, _⟩⟩

Goal state after:
case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
𝒰 : Ultrafilter X
F : Set (X × Filter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this : IsClosed (Prod.map f id '' F)
x : X
hy : Tendsto f (↑𝒰) (nhds (f x))
hx : (x, 𝒰.1) ∈ F
⊢ ∃ x_1, f x_1 = f x ∧ ↑𝒰 ≤ nhds x_1
Module: Mathlib.Topology.Maps.Proper.UniversallyClosed

Goal state before:
pp: case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
𝒰 : Ultrafilter X
F : Set (X × Filter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this : IsClosed (Prod.map f id '' F)
x : X
hy : Tendsto f (↑𝒰) (nhds (f x))
hx : (x, 𝒰.1) ∈ F
⊢ ∃ x_1, f x_1 = f x ∧ ↑𝒰 ≤ nhds x_1

Tactic:
refine ⟨x, rfl, fun U hU ↦ Ultrafilter.compl_notMem_iff.mp fun hUc ↦ ?_⟩

Goal state after:
case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
𝒰 : Ultrafilter X
F : Set (X × Filter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this : IsClosed (Prod.map f id '' F)
x : X
hy : Tendsto f (↑𝒰) (nhds (f x))
hx : (x, 𝒰.1) ∈ F
U : Set X
hU : U ∈ nhds x
hUc : Uᶜ ∈ 𝒰
⊢ False
Module: Mathlib.Topology.Maps.Proper.UniversallyClosed

Goal state before:
pp: case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
⊢ IsProperMap f

Tactic:
· rw [isProperMap_iff_ultrafilter]
  -- Let `𝒰 : Ultrafilter X`, and assume that `f` tends to some `y` along `𝒰`.
    refine ⟨H.1, fun 𝒰 y hy ↦ ?_⟩
  -- In `X × Filter X`, consider the closed set `F := closure {(x, ℱ) | ℱ = pure x}`
    let F : Set (X × Filter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
  -- Since `f × id` is closed, the set `(f × id) '' F` is also closed.
    have := H.2 F isClosed_closure
  -- Let us show that `(y, 𝒰) ∈ (f × id) '' F`.
    have : (y, ↑𝒰) ∈ Prod.map f id '' F :=
  -- Note that, by the properties of the topology on `Filter X`, the function `pure : X → Filter X`
  -- tends to the point `𝒰` of `Filter X` along the filter `𝒰` on `X`. Since `f` tends to `y` along
  -- `𝒰`, we get that the function `(f, pure) : X → (Y, Filter X)` tends to `(y, 𝒰)` along
  -- `𝒰`. Furthermore, each `(f, pure)(x) = (f × id)(x, pure x)` is clearly an element of
  -- the closed set `(f × id) '' F`, thus the limit `(y, 𝒰)` also belongs to that set.
      this.mem_of_tendsto (hy.prodMk_nhds (Filter.tendsto_pure_self (𝒰 : Filter X)))
        (Eventually.of_forall fun x ↦ ⟨⟨x, pure x⟩, subset_closure rfl, rfl⟩)
  -- The above shows that `(y, 𝒰) = (f x, 𝒰)`, for some `x : X` such that `(x, 𝒰) ∈ F`.
    rcases this with ⟨⟨x, _⟩, hx, ⟨_, _⟩⟩
  -- We already know that `f x = y`, so to finish the proof we just have to check that `𝒰` tends
  -- to `x`. So, for `U ∈ 𝓝 x` arbitrary, let's show that `U ∈ 𝒰`. Since `𝒰` is an ultrafilter,
  -- it is enough to show that `Uᶜ` is not in `𝒰`.
    refine ⟨x, rfl, fun U hU ↦ Ultrafilter.compl_notMem_iff.mp fun hUc ↦ ?_⟩
    rw [mem_closure_iff_nhds] at hx
  -- Indeed, if that was the case, the set `V := {𝒢 : Filter X | Uᶜ ∈ 𝒢}` would be a neighborhood
  -- of `𝒰` in `Filter X`, hence `U ×ˢ V` would be a neighborhood of `(x, 𝒰) : X × Filter X`.
  -- But recall that `(x, 𝒰) ∈ F = closure {(x, ℱ) | ℱ = pure x}`, so the neighborhood `U ×ˢ V`
  -- must contain some element of the form `(z, pure z)`. In other words, we have `z ∈ U` and
  -- `Uᶜ ∈ pure z`, which means `z ∈ Uᶜ` by the definition of pure.
  -- This is a contradiction, which completes the proof.
    rcases hx (U ×ˢ {𝒢 | Uᶜ ∈ 𝒢}) (prod_mem_nhds hU (isOpen_setOfPred_mem.mem_nhds hUc)) with
      ⟨⟨z, 𝒢⟩, ⟨⟨hz : z ∈ U, hz' : Uᶜ ∈ 𝒢⟩, rfl : 𝒢 = pure z⟩⟩
    exact hz' hz

Goal state after:
Module: Mathlib.Topology.Maps.Proper.UniversallyClosed

Goal state before:
pp: case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
𝒰 : Ultrafilter X
y : Y
hy : Tendsto f (↑𝒰) (nhds y)
F : Set (X × Ultrafilter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this✝ : IsClosed (Prod.map f id '' F)
this : (y, 𝒰) ∈ Prod.map f id '' F
⊢ ∃ x, f x = y ∧ ↑𝒰 ≤ nhds x

Tactic:
rcases this with ⟨⟨x, _⟩, hx, ⟨_, _⟩⟩

Goal state after:
case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
F : Set (X × Ultrafilter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this : IsClosed (Prod.map f id '' F)
x : X
snd✝ : Ultrafilter X
hx : (x, snd✝) ∈ F
hy : Tendsto f (↑(id snd✝)) (nhds (f x))
⊢ ∃ x_1, f x_1 = f x ∧ ↑(id snd✝) ≤ nhds x_1
Module: Mathlib.Topology.Maps.Proper.UniversallyClosed

Goal state before:
pp: case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
F : Set (X × Ultrafilter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this : IsClosed (Prod.map f id '' F)
x : X
snd✝ : Ultrafilter X
hx : (x, snd✝) ∈ F
hy : Tendsto f (↑(id snd✝)) (nhds (f x))
⊢ ∃ x_1, f x_1 = f x ∧ ↑(id snd✝) ≤ nhds x_1

Tactic:
refine ⟨x, rfl, fun U hU ↦ Ultrafilter.compl_notMem_iff.mp fun hUc ↦ ?_⟩

Goal state after:
case mpr
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f : X → Y
H : Continuous f ∧ IsClosedMap (Prod.map f id)
F : Set (X × Ultrafilter X) := closure {xℱ | xℱ.2 = pure xℱ.1}
this : IsClosed (Prod.map f id '' F)
x : X
snd✝ : Ultrafilter X
hx : (x, snd✝) ∈ F
hy : Tendsto f (↑(id snd✝)) (nhds (f x))
U : Set X
hU : U ∈ nhds x
hUc : Uᶜ ∈ id snd✝
⊢ False
Module: Mathlib.Topology.MetricSpace.BundledFun

Goal state before:
pp: X : Type u_1
R : Type u_2
inst✝³ : AddZeroClass R
inst✝² : SemilatticeSup R
inst✝¹ : AddLeftMono R
inst✝ : AddRightMono R
d d' : PseudoMetric X R
⊢ ∀ (x y z : X), d x z ⊔ d' x z ≤ d x y ⊔ d' x y + d y z ⊔ d' y z

Tactic:
intro x y z
      simp only [sup_le_iff]
      refine ⟨(d.triangle x y z).trans ?_, (d'.triangle x y z).trans ?_⟩ <;>
      apply add_le_add <;> simp

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:
LipschitzOnWith.coordinate

Goal state after:
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, LipschitzWith K g ∧ EqOn f g s
Module: Mathlib.Topology.MetricSpace.Infsep

Goal state before:
pp: α : Type u_1
inst✝¹ : EDist α
s : Set α
inst✝ : Fintype ↑s
x✝ : ℝ≥0∞
⊢ (∀ (x x_1 : α), x ∈ s → x_1 ∈ s → x ≠ x_1 → x✝ ≤ edist x x_1) ↔ ∀ b ∈ s.offDiag.toFinset, x✝ ≤ uncurry edist b

Tactic:
mem_toFinset,

Goal state after:
α : Type u_1
inst✝¹ : EDist α
s : Set α
inst✝ : Fintype ↑s
x✝ : ℝ≥0∞
⊢ (∀ (x x_1 : α), x ∈ s → x_1 ∈ s → x ≠ x_1 → x✝ ≤ edist x x_1) ↔ ∀ b ∈ s.offDiag, x✝ ≤ uncurry edist b
Module: Mathlib.Topology.MetricSpace.Infsep

Goal state before:
pp: case pos
α : Type u_1
inst✝ : PseudoEMetricSpace α
x y : α
hxy : x = y
⊢ {x, y}.infsep = (edist x y).toReal

Tactic:
hxy

Goal state after:
case pos
α : Type u_1
inst✝ : PseudoEMetricSpace α
x y : α
hxy : x = y
⊢ {y, y}.infsep = (edist y y).toReal
Module: Mathlib.Topology.MetricSpace.Infsep

Goal state before:
pp: case pos
α : Type u_1
inst✝² : PseudoMetricSpace α
s : Set α
inst✝¹ : Decidable s.Nontrivial
inst✝ : Fintype ↑s
hs : s.Nontrivial
x✝ : ℝ
⊢ (∀ (x x_1 : α), x ∈ s → x_1 ∈ s → x ≠ x_1 → x✝ ≤ dist x x_1) ↔ ∀ b ∈ s.offDiag.toFinset, x✝ ≤ uncurry dist b

Tactic:
mem_toFinset,

Goal state after:
case pos
α : Type u_1
inst✝² : PseudoMetricSpace α
s : Set α
inst✝¹ : Decidable s.Nontrivial
inst✝ : Fintype ↑s
hs : s.Nontrivial
x✝ : ℝ
⊢ (∀ (x x_1 : α), x ∈ s → x_1 ∈ s → x ≠ x_1 → x✝ ≤ dist x x_1) ↔ ∀ b ∈ s.offDiag, x✝ ≤ uncurry dist b
Module: Mathlib.Topology.MetricSpace.GromovHausdorff

Goal state before:
pp: X : Type u
inst✝⁶ : MetricSpace X
inst✝⁵ : CompactSpace X
inst✝⁴ : Nonempty X
Y : Type v
inst✝³ : MetricSpace Y
inst✝² : CompactSpace Y
inst✝¹ : Nonempty Y
γ : Type w
inst✝ : MetricSpace γ
Φ : X → γ
Ψ : Y → γ
ha : Isometry Φ
hb : Isometry Ψ
xX : X
h✝ : xX ∈ univ
s : Set γ := range Φ ∪ range Ψ
⊢ ghDist X Y ≤ hausdorffDist (range Φ) (range Ψ)

Tactic:
let Φ' : X → s := fun y => ⟨Φ y, mem_union_left _ (mem_range_self _)⟩

Goal state after:
X : Type u
inst✝⁶ : MetricSpace X
inst✝⁵ : CompactSpace X
inst✝⁴ : Nonempty X
Y : Type v
inst✝³ : MetricSpace Y
inst✝² : CompactSpace Y
inst✝¹ : Nonempty Y
γ : Type w
inst✝ : MetricSpace γ
Φ : X → γ
Ψ : Y → γ
ha : Isometry Φ
hb : Isometry Ψ
xX : X
h✝ : xX ∈ univ
s : Set γ := range Φ ∪ range Ψ
Φ' : X → ↑s := fun y ↦ ⟨Φ y, ⋯⟩
⊢ ghDist X Y ≤ hausdorffDist (range Φ) (range Ψ)
Module: Mathlib.Topology.MetricSpace.GromovHausdorff

Goal state before:
pp: 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
⊢ hausdorffDist (range (optimalGHInjl X Y)) (range (optimalGHInjr X Y)) ≤ hausdorffDist ↑p ↑q

Tactic:
rcases eq_toGHSpace_iff.1 hq with ⟨Ψ, ⟨Ψisom, Ψrange⟩⟩

Goal state after:
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
⊢ hausdorffDist (range (optimalGHInjl X Y)) (range (optimalGHInjr X Y)) ≤ hausdorffDist ↑p ↑q
Module: Mathlib.Topology.Order.LowerUpperTopology

Goal state before:
pp: h : Set Prop
hs : h ∈ {Ioi True, Ioi False}
⊢ ∃ a, Ioi a = h

Tactic:
rcases hs with (rfl | rfl)

Goal state after:
case inl
⊢ ∃ a, Ioi a = Ioi True

case inr
⊢ ∃ a, Ioi a = Ioi False
Module: Mathlib.Topology.Order.Priestley

Goal state before:
pp: case inr
α : Type u_1
inst✝² : TopologicalSpace α
inst✝¹ : PartialOrder α
inst✝ : PriestleySpace α
x y : α
h✝ : x ≠ y
h : ¬y ≤ x
U : Set α
hU : IsClopen U
hU' : IsLowerSet U
hy : y ∉ U
hx : x ∈ U
⊢ ∃ U, IsClopen U ∧ (IsUpperSet U ∨ IsLowerSet U) ∧ x ∈ U ∧ y ∉ U

Tactic:
exact ⟨U, hU, Or.inr hU', hx, hy⟩

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

Goal state before:
pp: x y : GHSpace
⊢ dist x y = dist y x

Tactic:
by
    have A :
      (fun p : NonemptyCompacts ℓ_infty_ℝ × NonemptyCompacts ℓ_infty_ℝ =>
            hausdorffDist (p.1 : Set ℓ_infty_ℝ) p.2) ''
          { a | ⟦a⟧ = x } ×ˢ { b | ⟦b⟧ = y } =
        (fun p : NonemptyCompacts ℓ_infty_ℝ × NonemptyCompacts ℓ_infty_ℝ =>
              hausdorffDist (p.1 : Set ℓ_infty_ℝ) p.2) ∘
            Prod.swap ''
          { a | ⟦a⟧ = x } ×ˢ { b | ⟦b⟧ = y } := by
      ext
      simp only [comp_apply, Prod.fst_swap, Prod.snd_swap, hausdorffDist_comm]
    simp only [dist, A, image_comp, image_swap_prod]

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

Goal state before:
pp: x y : GHSpace
hxy : dist x y = 0
Φ : x.Rep → ↥(lp (fun n ↦ ℝ) ∞)
Ψ : y.Rep → ↥(lp (fun n ↦ ℝ) ∞)
Φisom : Isometry Φ
Ψisom : Isometry Ψ
DΦΨ : dist x y = hausdorffDist (range Φ) (range Ψ)
⊢ x = y

Tactic:
hxy

Goal state after:
x y : GHSpace
hxy : dist x y = 0
Φ : x.Rep → ↥(lp (fun n ↦ ℝ) ∞)
Ψ : y.Rep → ↥(lp (fun n ↦ ℝ) ∞)
Φisom : Isometry Φ
Ψisom : Isometry Ψ
DΦΨ : 0 = hausdorffDist (range Φ) (range Ψ)
⊢ x = y
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:
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.Sheaves.SheafCondition.EqualizerProducts

Goal state before:
pp: case op.pair
C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : HasProducts C
X : TopCat
F : Presheaf C X
ι : Type v'
U : ι → Opens ↑X
c : Cone (SheafConditionEqualizerProducts.diagram F U)
i j : ι
⊢ ((Functor.const (CategoryTheory.Pairwise ι)ᵒᵖ).obj c.pt).obj (op (Pairwise.pair i j)) ⟶
    ((diagram U).op ⋙ F).obj (op (Pairwise.pair i j))

Tactic:
exact c.π.app WalkingParallelPair.one ≫ Pi.π _ (i, j)

Goal state after:
Module: Mathlib.Topology.Spectral.ConstructibleTopology

Goal state before:
pp: case pos
X : Type u_1
inst✝⁴ : TopologicalSpace X
inst✝³ : CompactSpace X
inst✝² : QuasiSober X
inst✝¹ : PrespectralSpace X
inst✝ : QuasiSeparatedSpace X
𝔅 : Set (Set X) := constructibleTopologySubbasis X
𝒮 : Set (Set (Set X)) := {P | P ⊆ 𝔅 ∧ (∀ Q ⊆ P, Q.Finite → (⋂₀ Q).Nonempty) ∧ ⋂₀ P = ∅}
s : Set (Set X)
hs : s ∈ 𝒮
B : Set (Set X)
hsB : s ⊆ B
hB : Maximal (fun x ↦ x ∈ 𝒮) B
B' : Set (Set X) := {s | s ∈ B ∧ IsClosed[inst✝⁴] s}
Z : Set X := ⋂₀ B'
hZ_closed : IsClosed[inst✝⁴] Z
hZ_nonempty : Z.Nonempty
hZ_irred : IsIrreducible Z
⊢ False

Tactic:
suffices (⋂₀ B).Nonempty by simp_all [hB.prop.2.2]

Goal state after:
case pos
X : Type u_1
inst✝⁴ : TopologicalSpace X
inst✝³ : CompactSpace X
inst✝² : QuasiSober X
inst✝¹ : PrespectralSpace X
inst✝ : QuasiSeparatedSpace X
𝔅 : Set (Set X) := constructibleTopologySubbasis X
𝒮 : Set (Set (Set X)) := {P | P ⊆ 𝔅 ∧ (∀ Q ⊆ P, Q.Finite → (⋂₀ Q).Nonempty) ∧ ⋂₀ P = ∅}
s : Set (Set X)
hs : s ∈ 𝒮
B : Set (Set X)
hsB : s ⊆ B
hB : Maximal (fun x ↦ x ∈ 𝒮) B
B' : Set (Set X) := {s | s ∈ B ∧ IsClosed[inst✝⁴] s}
Z : Set X := ⋂₀ B'
hZ_closed : IsClosed[inst✝⁴] Z
hZ_nonempty : Z.Nonempty
hZ_irred : IsIrreducible Z
⊢ (⋂₀ B).Nonempty