mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.CategoryTheory.Abelian.GrothendieckAxioms.Basic

Goal state before:
pp: C : Type u
inst✝⁴ : Category.{v, u} C
inst✝³ : HasFilteredColimitsOfSize.{w₂, w₂', v, u} C
inst✝² : UnivLE.{w, w₂}
inst✝¹ : UnivLE.{w', w₂'}
inst✝ : AB5OfSize.{w₂, w₂', v, u} C
⊢ AB5OfSize.{w, w', v, u} C

Tactic:
have : HasFilteredColimitsOfSize.{w, w'} C := hasFilteredColimitsOfSize_of_univLE.{w}
  constructor
  intro J _ _
  have := IsFiltered.of_equivalence ((ShrinkHoms.equivalence.{w₂} J).trans <|
    Shrink.equivalence.{w₂', w₂} (ShrinkHoms.{w'} J))
  exact HasExactColimitsOfShape.of_domain_equivalence _ ((ShrinkHoms.equivalence.{w₂} J).trans <|
    Shrink.equivalence.{w₂', w₂} (ShrinkHoms.{w'} J)).symm

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Presheaf

Goal state before:
pp: C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
ℰ : Type u₂
inst✝ : Category.{v₂, u₂} ℰ
A : C ⥤ ℰ
P : Cᵒᵖ ⥤ Type (max w v₁ v₂)
E : ℰ
g : P ⟶ (restrictedULiftYoneda A).obj E
X : Cᵒᵖ
x : P.obj X
⊢ (hom
          (((fun f ↦
                  { app := fun x ↦ ↾fun x_1 ↦ { down := f.app (CostructuredArrow.mk (uliftYonedaEquiv.symm x_1)) },
                    naturality := ⋯ })
                ((fun g ↦ { app := fun y ↦ (uliftYonedaEquiv (y.hom ≫ g)).down, naturality := ⋯ }) g)).app
            X)).toFun
      x =
    (hom (g.app X)).toFun x

Tactic:
apply ULift.down_injective

Goal state after:
C : Type u₁
inst✝¹ : Category.{v₁, u₁} C
ℰ : Type u₂
inst✝ : Category.{v₂, u₂} ℰ
A : C ⥤ ℰ
P : Cᵒᵖ ⥤ Type (max w v₁ v₂)
E : ℰ
g : P ⟶ (restrictedULiftYoneda A).obj E
X : Cᵒᵖ
x : P.obj X
⊢ ((hom
            (((fun f ↦
                    { app := fun x ↦ ↾fun x_1 ↦ { down := f.app (CostructuredArrow.mk (uliftYonedaEquiv.symm x_1)) },
                      naturality := ⋯ })
                  ((fun g ↦ { app := fun y ↦ (uliftYonedaEquiv (y.hom ≫ g)).down, naturality := ⋯ }) g)).app
              X)).toFun
        x).down =
    ((hom (g.app X)).toFun x).down
Module: Mathlib.CategoryTheory.Limits.Constructions.WeaklyInitial

Goal state before:
pp: C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : HasWideEqualizers C
T : C
hT : ∀ (X : C), Nonempty (T ⟶ X)
endos : Type v := T ⟶ T
i : wideEqualizer id ⟶ T := wideEqualizer.ι id
this✝ : Nonempty endos
X : C
a : wideEqualizer id ⟶ X
E : C := equalizer a (i ≫ Classical.choice ⋯)
e : E ⟶ wideEqualizer id := equalizer.ι a (i ≫ Classical.choice ⋯)
h : T ⟶ E := Classical.choice ⋯
this : ((i ≫ h) ≫ e) ≫ i = i ≫ 𝟙 T
⊢ a = default

Tactic:
rw [Category.comp_id, cancel_mono_id i] at this

Goal state after:
C : Type u
inst✝¹ : Category.{v, u} C
inst✝ : HasWideEqualizers C
T : C
hT : ∀ (X : C), Nonempty (T ⟶ X)
endos : Type v := T ⟶ T
i : wideEqualizer id ⟶ T := wideEqualizer.ι id
this✝ : Nonempty endos
X : C
a : wideEqualizer id ⟶ X
E : C := equalizer a (i ≫ Classical.choice ⋯)
e : E ⟶ wideEqualizer id := equalizer.ι a (i ≫ Classical.choice ⋯)
h : T ⟶ E := Classical.choice ⋯
this : (i ≫ h) ≫ e = 𝟙 (wideEqualizer id)
⊢ a = default
Module: Mathlib.CategoryTheory.Subobject.Comma

Goal state before:
pp: C : Type u₁
inst✝² : Category.{v₁, u₁} C
D : Type u₂
inst✝¹ : Category.{v₂, u₂} D
S : C ⥤ D
T : D
A : CostructuredArrow S T
P : (CostructuredArrow S T)ᵒᵖ
f : P ⟶ op A
inst✝ : Mono f.unop.left.op
⊢ f.unop.left ≫ (Subobject.underlyingIso f.unop.left.op).hom.unop = (Subobject.mk f.unop.left.op).arrow.unop

Tactic:
by
  conv_lhs =>
    congr
    rw [← Quiver.Hom.unop_op f.unop.left]
  rw [← unop_comp, Subobject.underlyingIso_hom_comp_eq_mk]

Goal state after:
Module: Mathlib.CategoryTheory.Subobject.Comma

Goal state before:
pp: case refine_1
C : Type u₁
inst✝³ : Category.{v₁, u₁} C
D : Type u₂
inst✝² : Category.{v₂, u₂} D
S : C ⥤ D
T : D
inst✝¹ : HasFiniteColimits C
inst✝ : PreservesFiniteColimits S
A : CostructuredArrow S T
P Q : (CostructuredArrow S T)ᵒᵖ
f : P ⟶ op A
g : Q ⟶ op A
hf : Mono f
hg : Mono g
h :
  { toFun := fun P ↦ ⟨projectQuotient P, ⋯⟩, invFun := fun P ↦ liftQuotient ↑P ⋯, left_inv := ⋯, right_inv := ⋯ }
      (Subobject.mk f) ≤
    { toFun := fun P ↦ ⟨projectQuotient P, ⋯⟩, invFun := fun P ↦ liftQuotient ↑P ⋯, left_inv := ⋯, right_inv := ⋯ }
      (Subobject.mk g)
⊢ S.map g.unop.left ≫ S.map (Subobject.ofMkLEMk f.unop.left.op g.unop.left.op h).unop ≫ (unop P).hom =
    S.map g.unop.left ≫ (unop Q).hom

Tactic:
simp only [← S.map_comp_assoc, unop_left_comp_ofMkLEMk_unop, unop_op, CommaMorphism.w,
        right_eq_id, Functor.const_obj_map]

Goal state after:
Module: Mathlib.CategoryTheory.Limits.Presheaf

Goal state before:
pp: C : Type u₁
inst✝² : Category.{v₁, u₁} C
D : Type u₂
inst✝¹ : Category.{v₂, u₂} D
F : C ⥤ D
G : (Cᵒᵖ ⥤ Type (max w v₁ v₂)) ⥤ Dᵒᵖ ⥤ Type (max w v₁ v₂)
φ : F ⋙ uliftYoneda.{max w v₁, v₂, u₂} ⟶ uliftYoneda.{max w v₂, v₁, u₁} ⋙ G
inst✝ : ∀ (P : Cᵒᵖ ⥤ Type (max w v₁ v₂)), F.op.HasLeftKanExtension P
X : C
⊢ F.op.lanUnit.app (uliftYoneda.{max v₂ w, v₁, u₁}.obj X) ≫
      F.op.whiskerLeft
        ((F.op.lan.obj (uliftYoneda.{max w v₂, v₁, u₁}.obj X)).descOfIsLeftKanExtension
          (F.op.lanUnit.app (uliftYoneda.{max w v₂, v₁, u₁}.obj X)) (G.obj (uliftYoneda.{max w v₂, v₁, u₁}.obj X))
          (presheafHom φ (uliftYoneda.{max w v₂, v₁, u₁}.obj X))) =
    F.op.lanUnit.app (uliftYoneda.{max v₂ w, v₁, u₁}.obj X) ≫
      F.op.whiskerLeft ((compULiftYonedaIsoULiftYonedaCompLan F).inv.app X ≫ φ.app X)

Tactic:
Functor.descOfIsLeftKanExtension_fac

Goal state after:
C : Type u₁
inst✝² : Category.{v₁, u₁} C
D : Type u₂
inst✝¹ : Category.{v₂, u₂} D
F : C ⥤ D
G : (Cᵒᵖ ⥤ Type (max w v₁ v₂)) ⥤ Dᵒᵖ ⥤ Type (max w v₁ v₂)
φ : F ⋙ uliftYoneda.{max w v₁, v₂, u₂} ⟶ uliftYoneda.{max w v₂, v₁, u₁} ⋙ G
inst✝ : ∀ (P : Cᵒᵖ ⥤ Type (max w v₁ v₂)), F.op.HasLeftKanExtension P
X : C
⊢ presheafHom φ (uliftYoneda.{max w v₂, v₁, u₁}.obj X) =
    F.op.lanUnit.app (uliftYoneda.{max v₂ w, v₁, u₁}.obj X) ≫
      F.op.whiskerLeft ((compULiftYonedaIsoULiftYonedaCompLan F).inv.app X ≫ φ.app X)
Module: Mathlib.GroupTheory.Divisible

Goal state before:
pp: A : Type u_1
α : Type u_2
inst✝² : Monoid A
inst✝¹ : Pow A α
inst✝ : Zero α
H : ∀ {n : α}, n ≠ 0 → Function.Surjective fun a ↦ a ^ n
n✝ : α
a : A
hn : n✝ ≠ 0
⊢ ⋯.choose ^ n✝ = a

Tactic:
exact (H hn a).choose_spec

Goal state after:
Module: Mathlib.GroupTheory.Divisible

Goal state before:
pp: A : Type u_1
B : Type u_2
α : Type u_3
inst✝⁵ : Zero α
inst✝⁴ : Monoid A
inst✝³ : Monoid B
inst✝² : Pow A α
inst✝¹ : Pow B α
inst✝ : RootableBy A α
f : A → B
hf : Surjective f
hpow : ∀ (a : A) (n : α), f (a ^ n) = f a ^ n
n : α
hn : n ≠ 0
x : B
y : A
hy : f y = x
⊢ f (RootableBy.root y n) ^ n = x

Tactic:
rw [← hpow (RootableBy.root y n) n, RootableBy.root_cancel _ hn, hy]

Goal state after:
Module: Mathlib.Algebra.Ring.Periodic

Goal state before:
pp: α : Type u_1
β : Type u_2
f : α → β
c : α
inst✝¹ : AddGroup α
inst✝ : InvolutiveNeg β
h : Antiperiodic f c
n : ℤ
⊢ Antiperiodic f ((2 * n + 1) • c)

Tactic:
intro x
  rw [add_zsmul, one_zsmul, ← add_assoc, h, h.even_zsmul_periodic]

Goal state after:
Module: Mathlib.Algebra.Module.Injective

Goal state before:
pp: R : Type u
inst✝⁷ : Ring R
Q : Type v
inst✝⁶ : AddCommGroup Q
inst✝⁵ : Module R Q
M : Type u_1
N : Type u_2
inst✝⁴ : AddCommGroup M
inst✝³ : AddCommGroup N
inst✝² : Module R M
inst✝¹ : Module R N
i : M →ₗ[R] N
f : M →ₗ[R] Q
inst✝ : Fact (Function.Injective ⇑i)
y : N
z1 z2 : ↥(ideal i f y)
⊢ ↑(extensionOfMax i f).toLinearPMap ⟨↑(z1 + z2) • y, ⋯⟩ =
    ↑(extensionOfMax i f).toLinearPMap ⟨↑z1 • y, ⋯⟩ + ↑(extensionOfMax i f).toLinearPMap ⟨↑z2 • y, ⋯⟩

Tactic:
← (extensionOfMax i f).toLinearPMap.map_add

Goal state after:
R : Type u
inst✝⁷ : Ring R
Q : Type v
inst✝⁶ : AddCommGroup Q
inst✝⁵ : Module R Q
M : Type u_1
N : Type u_2
inst✝⁴ : AddCommGroup M
inst✝³ : AddCommGroup N
inst✝² : Module R M
inst✝¹ : Module R N
i : M →ₗ[R] N
f : M →ₗ[R] Q
inst✝ : Fact (Function.Injective ⇑i)
y : N
z1 z2 : ↥(ideal i f y)
⊢ ↑(extensionOfMax i f).toLinearPMap ⟨↑(z1 + z2) • y, ⋯⟩ =
    ↑(extensionOfMax i f).toLinearPMap (⟨↑z1 • y, ⋯⟩ + ⟨↑z2 • y, ⋯⟩)
Module: Mathlib.Algebra.Module.Injective

Goal state before:
pp: R : Type u
inst✝⁷ : Ring R
Q : Type v
inst✝⁶ : AddCommGroup Q
inst✝⁵ : Module R Q
M : Type u_1
N : Type u_2
inst✝⁴ : AddCommGroup M
inst✝³ : AddCommGroup N
inst✝² : Module R M
inst✝¹ : Module R N
i : M →ₗ[R] N
f : M →ₗ[R] Q
inst✝ : Fact (Function.Injective ⇑i)
h : Baer R Q
y : N
x : ↥(supExtensionOfMaxSingleton i f y)
r : R
a : N
ha : a ∈ (extensionOfMax i f).domain
eq1 : ↑x = ↑⟨a, ha⟩ + r • y
eq2 : ↑(fst i x) - a = (r - snd i x) • y
eq3 :
  (extendIdealTo i f h y) r =
    ↑(extensionOfMax i f).toLinearPMap ⟨r • y - snd i x • y, ⋯⟩ + (extendIdealTo i f h y) (snd i x)
⊢ ↑(extensionOfMax i f).toLinearPMap (fst i x) + (extendIdealTo i f h y) (snd i x) =
    ↑(extensionOfMax i f).toLinearPMap ⟨a, ha⟩ + (extendIdealTo i f h y) r

Tactic:
eq3,

Goal state after:
R : Type u
inst✝⁷ : Ring R
Q : Type v
inst✝⁶ : AddCommGroup Q
inst✝⁵ : Module R Q
M : Type u_1
N : Type u_2
inst✝⁴ : AddCommGroup M
inst✝³ : AddCommGroup N
inst✝² : Module R M
inst✝¹ : Module R N
i : M →ₗ[R] N
f : M →ₗ[R] Q
inst✝ : Fact (Function.Injective ⇑i)
h : Baer R Q
y : N
x : ↥(supExtensionOfMaxSingleton i f y)
r : R
a : N
ha : a ∈ (extensionOfMax i f).domain
eq1 : ↑x = ↑⟨a, ha⟩ + r • y
eq2 : ↑(fst i x) - a = (r - snd i x) • y
eq3 :
  (extendIdealTo i f h y) r =
    ↑(extensionOfMax i f).toLinearPMap ⟨r • y - snd i x • y, ⋯⟩ + (extendIdealTo i f h y) (snd i x)
⊢ ↑(extensionOfMax i f).toLinearPMap (fst i x) + (extendIdealTo i f h y) (snd i x) =
    ↑(extensionOfMax i f).toLinearPMap ⟨a, ha⟩ +
      (↑(extensionOfMax i f).toLinearPMap ⟨r • y - snd i x • y, ⋯⟩ + (extendIdealTo i f h y) (snd i x))
Module: Mathlib.Data.Nat.Totient

Goal state before:
pp: n : ℕ
⊢ Odd (φ n) ↔ n = 1 ∨ n = 2

Tactic:
by
  rcases n with _ | _ | _ | _ <;> simp [Nat.totient_even]

Goal state after:
Module: Mathlib.Topology.Basic

Goal state before:
pp: X : Type u
T : Set (Set X)
empty_mem : ∅ ∈ T
sInter_mem : ∀ A ⊆ T, ⋂₀ A ∈ T
union_mem : ∀ A ∈ T, ∀ B ∈ T, A ∪ B ∈ T
⊢ univᶜ ∈ T

Tactic:
by simp [empty_mem]

Goal state after:
Module: Mathlib.Topology.Basic

Goal state before:
pp: case empty
X : Type u
inst✝ : TopologicalSpace X
s : Set (Set X)
h : ∀ t ∈ ∅, IsOpen[inst✝] t
⊢ IsOpen[inst✝] (⋂₀ ∅)

Tactic:
sInter_empty

Goal state after:
case empty
X : Type u
inst✝ : TopologicalSpace X
s : Set (Set X)
h : ∀ t ∈ ∅, IsOpen[inst✝] t
⊢ IsOpen[inst✝] univ
Module: Mathlib.Order.Filter.Lift

Goal state before:
pp: α : Type u_1
β : Type u_2
ι : Sort u_4
inst✝ : Nonempty ι
f : ι → Filter α
g : Set α → Set β
hg : ∀ (s t : Set α), g (s ∩ t) = g s ∩ g t
s t : Set α
⊢ (𝓟 ∘ g) (s ∩ t) = (𝓟 ∘ g) s ⊓ (𝓟 ∘ g) t

Tactic:
simp only [inf_principal, comp, hg]

Goal state after:
Module: Mathlib.Order.Filter.Lift

Goal state before:
pp: α : Type u_1
β : Type u_2
ι : Sort u_4
f : ι → Filter α
g : Set α → Set β
hg : ∀ {s t : Set α}, g (s ∩ t) = g s ∩ g t
hg' : g univ = univ
s t : Set α
⊢ (𝓟 ∘ g) (s ∩ t) = (𝓟 ∘ g) s ⊓ (𝓟 ∘ g) t

Tactic:
simp only [inf_principal, comp, hg]

Goal state after:
Module: Mathlib.Topology.Closure

Goal state before:
pp: X : Type u
inst✝ : TopologicalSpace X
x : X
⊢ Dense {x}ᶜ ↔ ¬IsOpen {x}

Tactic:
constructor
  · intro hd ho
    exact (hd.inter_open_nonempty _ ho (singleton_nonempty _)).ne_empty (inter_compl_self _)
  · refine fun ho => dense_iff_inter_open.2 fun U hU hne => inter_compl_nonempty_iff.2 fun hUx => ?_
    obtain rfl : U = {x} := eq_singleton_iff_nonempty_unique_mem.2 ⟨hne, hUx⟩
    exact ho hU

Goal state after:
Module: Mathlib.Topology.Closure

Goal state before:
pp: X : Type u
inst✝ : TopologicalSpace X
s : Set X
⊢ frontier s = closure s ∩ closure sᶜ

Tactic:
by
  rw [closure_compl, frontier, sdiff_eq]

Goal state after:
Module: Mathlib.Topology.ClusterPt

Goal state before:
pp: X : Type u_3
inst✝ : TopologicalSpace X
x : X
C : Set X
⊢ (∃ᶠ (x_1 : X) in 𝓝 x, x_1 ∈ {x}ᶜ ∧ x_1 ∈ C) ↔ ∃ᶠ (z : X) in 𝓝 x, z ∈ C ∧ z ∈ {x}ᶜ

Tactic:
simp only [and_comm]

Goal state after:
Module: Mathlib.Algebra.Order.ToIntervalMod

Goal state before:
pp: case inl
α : Type u_1
inst✝² : AddCommGroup α
inst✝¹ : LinearOrder α
inst✝ : IsOrderedAddMonoid α
hα : Archimedean α
p : α
hp : 0 < p
x₁ x₂ x₃ : α
h✝ : toIcoMod hp x₁ x₂ ≤ toIocMod hp x₁ x₃
x₂' : α := toIcoMod hp x₁ x₂
x₃' : α := toIcoMod hp x₂' x₃
h : x₂' ≤ toIocMod hp x₁ x₃'
h₂₁ : x₂' < x₁ + p
h₃₂ : x₃' - p < x₂'
h₃₁ : x₃' ≤ x₁ + p
⊢ toIocMod hp x₂' x₁ = x₁ + p

Tactic:
apply (toIocMod_eq_iff hp).2

Goal state after:
case inl
α : Type u_1
inst✝² : AddCommGroup α
inst✝¹ : LinearOrder α
inst✝ : IsOrderedAddMonoid α
hα : Archimedean α
p : α
hp : 0 < p
x₁ x₂ x₃ : α
h✝ : toIcoMod hp x₁ x₂ ≤ toIocMod hp x₁ x₃
x₂' : α := ⋯
x₃' : α := ⋯
h : x₂' ≤ toIocMod hp x₁ x₃'
h₂₁ : x₂' < x₁ + p
h₃₂ : x₃' - p < x₂'
h₃₁ : x₃' ≤ x₁ + p
⊢ x₁ + p ∈ Set.Ioc x₂' (x₂' + p) ∧ ∃ z, x₁ = x₁ + p + z • p
Module: Mathlib.Algebra.Order.ToIntervalMod

Goal state before:
pp: α : Type u_1
inst✝² : AddCommGroup α
inst✝¹ : LinearOrder α
inst✝ : IsOrderedAddMonoid α
hα : Archimedean α
p : α
hp : 0 < p
x₁ x₂ x₃ : α
h✝ : toIcoMod hp x₁ x₂ ≤ toIocMod hp x₁ x₃
x₂' : α := toIcoMod hp x₁ x₂
x₃' : α := toIcoMod hp x₂' x₃
h : x₂' ≤ toIocMod hp x₁ x₃'
h₂₁ : x₂' < x₁ + p
h₃₂ : x₃' - p < x₂'
h₁₃ : x₁ + p < x₃'
⊢ toIocMod hp x₁ x₃' = x₃' - p

Tactic:
apply (toIocMod_eq_iff hp).2

Goal state after:
α : Type u_1
inst✝² : AddCommGroup α
inst✝¹ : LinearOrder α
inst✝ : IsOrderedAddMonoid α
hα : Archimedean α
p : α
hp : 0 < p
x₁ x₂ x₃ : α
h✝ : toIcoMod hp x₁ x₂ ≤ toIocMod hp x₁ x₃
x₂' : α := ⋯
x₃' : α := ⋯
h : x₂' ≤ toIocMod hp x₁ x₃'
h₂₁ : x₂' < x₁ + p
h₃₂ : x₃' - p < x₂'
h₁₃ : x₁ + p < x₃'
⊢ x₃' - p ∈ Set.Ioc x₁ (x₁ + p) ∧ ∃ z, x₃' = x₃' - p + z • p
Module: Mathlib.Algebra.Order.ToIntervalMod

Goal state before:
pp: R : Type u_1
inst✝³ : NonAssocRing R
inst✝² : LinearOrder R
inst✝¹ : IsOrderedAddMonoid R
inst✝ : Archimedean R
p : R
hp : 0 < p
a b : R
m : ℤ
⊢ toIcoDiv hp (a - ↑m * p) b = toIcoDiv hp a b + m

Tactic:
simpa using toIcoDiv_sub_zsmul' hp a b m

Goal state after:
Module: Mathlib.Algebra.Order.ToIntervalMod

Goal state before:
pp: α : Type u_1
inst✝³ : Field α
inst✝² : LinearOrder α
inst✝¹ : IsStrictOrderedRing α
inst✝ : FloorRing α
b : α
⊢ toIcoDiv ⋯ 0 b = ⌊b⌋

Tactic:
simp [toIcoDiv_eq_floor]

Goal state after:
Module: Mathlib.Topology.Homeomorph.Defs

Goal state before:
pp: X : Type u_1
Y : Type u_2
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
h : X ≃ₜ Y
s : Set X
⊢ ⇑h '' closure[inst✝¹] s = closure[inst✝] (⇑h '' s)

Tactic:
by
  rw [← preimage_symm, preimage_closure]

Goal state after:
Module: Mathlib.Topology.Order

Goal state before:
pp: α : Type u
β : Type v
f : α → β
t₁ t₂ : TopologicalSpace α
t₃ : TopologicalSpace β
h₁ : t₂ ≤ t₁
h₂ : Continuous[t₁, t₃] f
⊢ Continuous[t₂, t₃] f

Tactic:
by
  rw [continuous_iff_le_induced] at h₂ ⊢
  exact le_trans h₁ h₂

Goal state after:
Module: Mathlib.Topology.Constructions.SumProd

Goal state before:
pp: X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
s : Set (X × Y)
hs : IsClosed[instTopologicalSpaceProd] s
⊢ IsClosed[instTopologicalSpaceProd] (Prod.swap '' s)

Tactic:
by
  rw [image_swap_eq_preimage_swap]
  exact hs.preimage continuous_swap

Goal state after:
Module: Mathlib.Topology.NhdsWithin

Goal state before:
pp: α : Type u_1
inst✝ : TopologicalSpace α
z : α
s : Set α
p : α → Prop
⊢ (∃ᶠ (x : α) in 𝓝 z, x ∈ s ∧ p x) ↔ ∃ᶠ (x : α) in 𝓝 z, p x ∧ x ∈ s

Tactic:
simp only [and_comm]

Goal state after:
Module: Mathlib.Topology.Constructions.SumProd

Goal state before:
pp: X : Type u
Y : Type v
Z : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
inst✝ : TopologicalSpace Z
f : X → Z
g : Y → Z
hf : IsInducing f
hg : IsInducing g
hFg : Disjoint (𝓟 (range f)) (𝓝ˢ (range g))
hfG : Disjoint (𝓝ˢ (range f)) (𝓟 (range g))
x : X ⊕ Y
⊢ comap (Sum.elim f g) (𝓝 (Sum.elim f g x)) ≤ 𝓝 x

Tactic:
obtain x | x := x <;>
  simp only [comap_sumElim_eq, nhds_inl, nhds_inr, elim_inl, elim_inr, ← hf.nhds_eq_comap,
    ← hg.nhds_eq_comap, sup_le_iff, le_rfl, true_and, and_true]

Goal state after:
case inl
X : Type u
Y : Type v
Z : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
inst✝ : TopologicalSpace Z
f : X → Z
g : Y → Z
hf : IsInducing f
hg : IsInducing g
hFg : Disjoint (𝓟 (range f)) (𝓝ˢ (range g))
hfG : Disjoint (𝓝ˢ (range f)) (𝓟 (range g))
x : X
⊢ map inr (comap g (𝓝 (f x))) ≤ map inl (𝓝 x)

case inr
X : Type u
Y : Type v
Z : Type u_2
inst✝² : TopologicalSpace X
inst✝¹ : TopologicalSpace Y
inst✝ : TopologicalSpace Z
f : X → Z
g : Y → Z
hf : IsInducing f
hg : IsInducing g
hFg : Disjoint (𝓟 (range f)) (𝓝ˢ (range g))
hfG : Disjoint (𝓝ˢ (range f)) (𝓟 (range g))
x : Y
⊢ map inl (comap f (𝓝 (g x))) ≤ map inr (𝓝 x)
Module: Mathlib.Topology.Bases

Goal state before:
pp: α : Type u
t : TopologicalSpace α
B B' : Set (Set α)
hB : IsTopologicalBasis B
h_open : ∀ u ∈ B', IsOpen[t] u
h : ∀ u ∈ B, ∀ x ∈ u, ∃ v ∈ B', x ∈ v ∧ v ⊆ u
x : α
u : Set α
hx : x ∈ u
hu : IsOpen[t] u
⊢ ∃ v ∈ B', x ∈ v ∧ v ⊆ u

Tactic:
obtain ⟨w, hwB, hxw, hwu⟩ := hB.exists_subset_of_mem_open hx hu

Goal state after:
α : Type u
t : TopologicalSpace α
B B' : Set (Set α)
hB : IsTopologicalBasis B
h_open : ∀ u ∈ B', IsOpen[t] u
h : ∀ u ∈ B, ∀ x ∈ u, ∃ v ∈ B', x ∈ v ∧ v ⊆ u
x : α
u : Set α
hx : x ∈ u
hu : IsOpen[t] u
w : Set α
hwB : w ∈ B
hxw : x ∈ w
hwu : w ⊆ u
⊢ ∃ v ∈ B', x ∈ v ∧ v ⊆ u
Module: Mathlib.Topology.ContinuousOn

Goal state before:
pp: case refine_2
α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
inst✝ : TopologicalSpace β
f : α → β
s s' : Set α
t : Set β
hf : ContinuousOn f s'
hs' : s' ∈ 𝓝ˢ s
hst : MapsTo f s t
V : Set α
hV : IsOpen[inst✝¹] V
hsV : s ⊆ V
hVs' : V ⊆ s'
U : Set β
hU : IsOpen[inst✝] U ∧ t ⊆ U
x✝ : α
h : x✝ ∈ V ∩ f ⁻¹' U
⊢ f x✝ ∈ U

Tactic:
rw [← mem_preimage]

Goal state after:
case refine_2
α : Type u_1
β : Type u_2
inst✝¹ : TopologicalSpace α
inst✝ : TopologicalSpace β
f : α → β
s s' : Set α
t : Set β
hf : ContinuousOn f s'
hs' : s' ∈ 𝓝ˢ s
hst : MapsTo f s t
V : Set α
hV : IsOpen[inst✝¹] V
hsV : s ⊆ V
hVs' : V ⊆ s'
U : Set β
hU : IsOpen[inst✝] U ∧ t ⊆ U
x✝ : α
h : x✝ ∈ V ∩ f ⁻¹' U
⊢ x✝ ∈ f ⁻¹' U
Module: Mathlib.Topology.Constructions

Goal state before:
pp: case refine_2.refine_2
ι : Type u_5
A : ι → Type u_6
T : (i : ι) → TopologicalSpace (A i)
s : Set ((a : ι) → A a)
a : (a : ι) → A a
x✝ : a ∈ s
I : Finset ι
t : (a : ι) → Set (A a)
h1 : ∀ a_1 ∈ I, IsOpen[T a_1] (t a_1) ∧ a a_1 ∈ t a_1
h2 : (↑I).pi t ⊆ s
⊢ ((↑I).pi fun a ↦ if a ∈ I then t a else univ) ⊆ s

Tactic:
← univ_pi_ite

Goal state after:
case refine_2.refine_2
ι : Type u_5
A : ι → Type u_6
T : (i : ι) → TopologicalSpace (A i)
s : Set ((a : ι) → A a)
a : (a : ι) → A a
x✝ : a ∈ s
I : Finset ι
t : (a : ι) → Set (A a)
h1 : ∀ a_1 ∈ I, IsOpen[T a_1] (t a_1) ∧ a a_1 ∈ t a_1
h2 : (↑I).pi t ⊆ s
⊢ (univ.pi fun i ↦ if i ∈ ↑I then if i ∈ I then t i else univ else univ) ⊆ s
Module: Mathlib.Topology.Constructions

Goal state before:
pp: case refine_2
ι : Type u_5
A : ι → Type u_6
T : (i : ι) → TopologicalSpace (A i)
s : Set ((a : ι) → A a)
a : (a : ι) → A a
x✝ : a ∈ s
⊢ (∃ I u, (∀ a_1 ∈ I, IsOpen[T a_1] (u a_1) ∧ a a_1 ∈ u a_1) ∧ (↑I).pi u ⊆ s) →
    ∃ I t, (∀ (i : ι), ∃ t_1 ⊆ t i, IsOpen[T i] t_1 ∧ a i ∈ t_1) ∧ (↑I).pi t ⊆ s

Tactic:
rintro ⟨I, t, ⟨h1, h2⟩⟩
    classical
    refine ⟨I, fun a => ite (a ∈ I) (t a) univ, fun i => ?_, ?_⟩
    · by_cases hi : i ∈ I
      · use t i
        simp_rw [if_pos hi]
        exact ⟨Subset.rfl, (h1 i) hi⟩
      · use univ
        simp_rw [if_neg hi]
        exact ⟨Subset.rfl, isOpen_univ, mem_univ _⟩
    · rw [← univ_pi_ite]
      simp only [← ite_and, ← Finset.mem_coe, and_self_iff, univ_pi_ite, h2]

Goal state after:
Module: Mathlib.Topology.Constructions

Goal state before:
pp: ι : Type u_5
A : ι → Type u_6
T : (i : ι) → TopologicalSpace (A i)
inst✝ : DecidableEq ι
s : Set ((a : ι) → A a)
x : (a : ι) → A a
hs : s ∈ 𝓝 x
y : (a : ι) → A a
⊢ ∃ I, I.piecewise x y ∈ s

Tactic:
simp only [nhds_pi, Filter.mem_pi'] at hs
  rcases hs with ⟨I, t, htx, hts⟩
  refine ⟨I, hts fun i hi => ?_⟩
  simpa [Finset.mem_coe.1 hi] using mem_of_mem_nhds (htx i)

Goal state after:
Module: Mathlib.Topology.Constructions

Goal state before:
pp: case inr
ι : Type u_5
σ : ι → Type u_7
inst✝ : (i : ι) → TopologicalSpace (σ i)
i : ι
s : Set (σ i)
hs : IsClosed[inst✝ i] s
j : ι
hne : j ≠ i
⊢ IsClosed[inst✝ j] (Sigma.mk j ⁻¹' Sigma.mk i '' s)

Tactic:
rw [preimage_image_sigmaMk_of_ne hne]
    exact isClosed_empty

Goal state after:
Module: Mathlib.Topology.Compactness.SigmaCompact

Goal state before:
pp: X : Type u_1
ι : Type u_3
inst✝¹ : TopologicalSpace X
inst✝ : Countable ι
s : ι → Set X
hcomp✝ : ∀ (i : ι), IsSigmaCompact (s i)
K : ι → ℕ → Set X
hcomp : ∀ (i : ι) (n : ℕ), IsCompact (K i n)
hcov : ∀ (i : ι), ⋃ n, K i n = s i
⊢ ⋃ i, ⋃ n, Function.uncurry K (i, n) = ⋃ x, Function.uncurry K x

Tactic:
rw [← iUnion_prod']

Goal state after:
Module: Mathlib.Topology.Piecewise

Goal state before:
pp: case neg.inl
α : Type u_1
β : Type u_2
inst✝² : TopologicalSpace α
inst✝¹ : TopologicalSpace β
s : Set α
p : α → Prop
f g : α → β
inst✝ : (a : α) → Decidable (p a)
hpf : ∀ a ∈ s ∩ frontier {a | p a}, Tendsto f (𝓝[s ∩ {a | p a}] a) (𝓝 (if p a then f a else g a))
hpg : ∀ a ∈ s ∩ frontier {a | p a}, Tendsto g (𝓝[s ∩ {a | ¬p a}] a) (𝓝 (if p a then f a else g a))
hf : ContinuousOn f (s ∩ {a | p a})
hg : ContinuousOn g (s ∩ {a | ¬p a})
x : α
hx' : x ∉ frontier {a | p a}
hx : x ∈ s ∩ {a | p a}
⊢ ContinuousWithinAt (fun a ↦ if p a then f a else g a) (s ∩ {a | p a} ∪ s ∩ {a | p a}ᶜ) x

Tactic:
apply ContinuousWithinAt.union

Goal state after:
case neg.inl.hs
α : Type u_1
β : Type u_2
inst✝² : TopologicalSpace α
inst✝¹ : TopologicalSpace β
s : Set α
p : α → Prop
f g : α → β
inst✝ : (a : α) → Decidable (p a)
hpf : ∀ a ∈ s ∩ frontier {a | p a}, Tendsto f (𝓝[s ∩ {a | p a}] a) (𝓝 (if p a then f a else g a))
hpg : ∀ a ∈ s ∩ frontier {a | p a}, Tendsto g (𝓝[s ∩ {a | ¬p a}] a) (𝓝 (if p a then f a else g a))
hf : ContinuousOn f (s ∩ {a | p a})
hg : ContinuousOn g (s ∩ {a | ¬p a})
x : α
hx' : x ∉ frontier {a | p a}
hx : x ∈ s ∩ {a | p a}
⊢ ContinuousWithinAt (fun a ↦ if p a then f a else g a) (s ∩ {a | p a}) x

case neg.inl.ht
α : Type u_1
β : Type u_2
inst✝² : TopologicalSpace α
inst✝¹ : TopologicalSpace β
s : Set α
p : α → Prop
f g : α → β
inst✝ : (a : α) → Decidable (p a)
hpf : ∀ a ∈ s ∩ frontier {a | p a}, Tendsto f (𝓝[s ∩ {a | p a}] a) (𝓝 (if p a then f a else g a))
hpg : ∀ a ∈ s ∩ frontier {a | p a}, Tendsto g (𝓝[s ∩ {a | ¬p a}] a) (𝓝 (if p a then f a else g a))
hf : ContinuousOn f (s ∩ {a | p a})
hg : ContinuousOn g (s ∩ {a | ¬p a})
x : α
hx' : x ∉ frontier {a | p a}
hx : x ∈ s ∩ {a | p a}
⊢ ContinuousWithinAt (fun a ↦ if p a then f a else g a) (s ∩ {a | p a}ᶜ) x
Module: Mathlib.Topology.Compactness.Compact

Goal state before:
pp: X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
s s' : Set X
hs : IsCompact s
t : Set Y
ht : IsCompact t
n : Set (X × Y)
hn : n ∈ 𝓝ˢ[s' ×ˢ t] (s ×ˢ t)
⊢ ∃ u ∈ 𝓝ˢ[s'] s, u ×ˢ t ⊆ n

Tactic:
rw [hs.nhdsSetWithin_prod_eq ht, nhdsSetWithin_self, Filter.mem_prod_principal] at hn

Goal state after:
X : Type u
Y : Type v
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
s s' : Set X
hs : IsCompact s
t : Set Y
ht : IsCompact t
n : Set (X × Y)
hn : {a | ∀ b ∈ t, (a, b) ∈ n} ∈ 𝓝ˢ[s'] s
⊢ ∃ u ∈ 𝓝ˢ[s'] s, u ×ˢ t ⊆ n
Module: Mathlib.Topology.Inseparable

Goal state before:
pp: X : Type u_1
inst✝ : TopologicalSpace X
x y : X
tfae_1_to_2 : x ⤳ y → pure x ≤ 𝓝 y
tfae_2_to_3 : pure x ≤ 𝓝 y → ∀ (s : Set X), IsOpen[inst✝] s → y ∈ s → x ∈ s
⊢ [x ⤳ y, pure x ≤ 𝓝 y, ∀ (s : Set X), IsOpen[inst✝] s → y ∈ s → x ∈ s,
      ∀ (s : Set X), IsClosed[inst✝] s → x ∈ s → y ∈ s, y ∈ closure[inst✝] {x}, closure[inst✝] {y} ⊆ closure[inst✝] {x},
      ClusterPt y (pure x)].TFAE

Tactic:
tfae_have 3 → 4 := fun h s hsc hx => of_not_not fun hy => h sᶜ hsc.isOpen_compl hy hx

Goal state after:
X : Type u_1
inst✝ : TopologicalSpace X
x y : X
tfae_1_to_2 : x ⤳ y → pure x ≤ 𝓝 y
tfae_2_to_3 : pure x ≤ 𝓝 y → ∀ (s : Set X), IsOpen[inst✝] s → y ∈ s → x ∈ s
tfae_3_to_4 : (∀ (s : Set X), IsOpen[inst✝] s → y ∈ s → x ∈ s) → ∀ (s : Set X), IsClosed[inst✝] s → x ∈ s → y ∈ s
⊢ [x ⤳ y, pure x ≤ 𝓝 y, ∀ (s : Set X), IsOpen[inst✝] s → y ∈ s → x ∈ s,
      ∀ (s : Set X), IsClosed[inst✝] s → x ∈ s → y ∈ s, y ∈ closure[inst✝] {x}, closure[inst✝] {y} ⊆ closure[inst✝] {x},
      ClusterPt y (pure x)].TFAE