mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Geometry.Manifold.MFDeriv.Basic

Goal state before:
pp: case mp
𝕜 : Type u_1
inst✝¹² : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹¹ : NormedAddCommGroup E
inst✝¹⁰ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁹ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁸ : TopologicalSpace M
inst✝⁷ : ChartedSpace H M
E' : Type u_5
inst✝⁶ : NormedAddCommGroup E'
inst✝⁵ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝⁴ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝³ : TopologicalSpace M'
inst✝² : ChartedSpace H' M'
f : M → M'
s : Set M
inst✝¹ : IsManifold I 1 M
inst✝ : IsManifold I' 1 M'
h : MDiff[s] f
x : M
y : M'
z : E
hz :
  (z ∈ range ↑I ∧ ↑I.symm z ∈ (chartAt H x).target) ∧
    ↑(chartAt H x).symm (↑I.symm z) ∈ s ∧ f (↑(chartAt H x).symm (↑I.symm z)) ∈ (chartAt H' y).source
w : M := ↑(extChartAt I x).symm z
this : w ∈ s
⊢ DifferentiableWithinAt 𝕜 (↑(extChartAt I' y) ∘ f ∘ ↑(extChartAt I x).symm)
    ((extChartAt I x).target ∩ ↑(extChartAt I x).symm ⁻¹' (s ∩ f ⁻¹' (extChartAt I' y).source)) z

Tactic:
specialize h w this

Goal state after:
case mp
𝕜 : Type u_1
inst✝¹² : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹¹ : NormedAddCommGroup E
inst✝¹⁰ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁹ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁸ : TopologicalSpace M
inst✝⁷ : ChartedSpace H M
E' : Type u_5
inst✝⁶ : NormedAddCommGroup E'
inst✝⁵ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝⁴ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝³ : TopologicalSpace M'
inst✝² : ChartedSpace H' M'
f : M → M'
s : Set M
inst✝¹ : IsManifold I 1 M
inst✝ : IsManifold I' 1 M'
x : M
y : M'
z : E
hz :
  (z ∈ range ↑I ∧ ↑I.symm z ∈ (chartAt H x).target) ∧
    ↑(chartAt H x).symm (↑I.symm z) ∈ s ∧ f (↑(chartAt H x).symm (↑I.symm z)) ∈ (chartAt H' y).source
w : M := ↑(extChartAt I x).symm z
h : MDiffAt[s] f w
this : w ∈ s
⊢ DifferentiableWithinAt 𝕜 (↑(extChartAt I' y) ∘ f ∘ ↑(extChartAt I x).symm)
    ((extChartAt I x).target ∩ ↑(extChartAt I x).symm ⁻¹' (s ∩ f ⁻¹' (extChartAt I' y).source)) z
Module: Mathlib.Topology.FiberBundle.Constructions

Goal state before:
pp: B : Type u_1
inst✝⁶ : TopologicalSpace B
F₁ : Type u_2
inst✝⁵ : TopologicalSpace F₁
E₁ : B → Type u_3
inst✝⁴ : TopologicalSpace (TotalSpace F₁ E₁)
F₂ : Type u_4
inst✝³ : TopologicalSpace F₂
E₂ : B → Type u_5
inst✝² : TopologicalSpace (TotalSpace F₂ E₂)
e₁ : Trivialization F₁ TotalSpace.proj
e₂ : Trivialization F₂ TotalSpace.proj
inst✝¹ : (x : B) → Zero (E₁ x)
inst✝ : (x : B) → Zero (E₂ x)
x : B
v₁ : E₁ x
v₂ : E₂ x
h₁ : x ∈ e₁.baseSet
h₂ : x ∈ e₂.baseSet
⊢ invFun' e₁ e₂ (toFun' e₁ e₂ { proj := x, snd := (v₁, v₂) }) = { proj := x, snd := (v₁, v₂) }

Tactic:
simp [Prod.toFun', Prod.invFun', h₁, h₂]

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

Goal state before:
pp: B : Type u_1
inst✝⁶ : TopologicalSpace B
F₁ : Type u_2
inst✝⁵ : TopologicalSpace F₁
E₁ : B → Type u_3
inst✝⁴ : TopologicalSpace (TotalSpace F₁ E₁)
F₂ : Type u_4
inst✝³ : TopologicalSpace F₂
E₂ : B → Type u_5
inst✝² : TopologicalSpace (TotalSpace F₂ E₂)
e₁ : Trivialization F₁ TotalSpace.proj
e₂ : Trivialization F₂ TotalSpace.proj
inst✝¹ : (x : B) → Zero (E₁ x)
inst✝ : (x : B) → Zero (E₂ x)
x : B
w₁ : F₁
w₂ : F₂
h₁ : x ∈ e₁.baseSet
h₂ : x ∈ e₂.baseSet
⊢ toFun' e₁ e₂ (invFun' e₁ e₂ (x, w₁, w₂)) = (x, w₁, w₂)

Tactic:
simp [Prod.toFun', Prod.invFun', h₁, h₂]

Goal state after:
Module: Mathlib.Geometry.Manifold.MFDeriv.Basic

Goal state before:
pp: case inr
𝕜 : Type u_1
inst✝¹⁰ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
E' : Type u_5
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝² : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝¹ : TopologicalSpace M'
inst✝ : ChartedSpace H' M'
f : M → M'
x : M
s : Set M
f' : TangentSpace I x →L[𝕜] TangentSpace I' (f x)
y : M
this : T1Space M
hf : HasMFDerivAt[s] f x f'
h : x ≠ y
⊢ HasMFDerivAt[insert y s] f x f'

Tactic:
apply hf.mono_of_mem_nhdsWithin ?_

Goal state after:
𝕜 : Type u_1
inst✝¹⁰ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
E' : Type u_5
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝² : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝¹ : TopologicalSpace M'
inst✝ : ChartedSpace H' M'
f : M → M'
x : M
s : Set M
f' : TangentSpace I x →L[𝕜] TangentSpace I' (f x)
y : M
this : T1Space M
hf : HasMFDerivAt[s] f x f'
h : x ≠ y
⊢ s ∈ 𝓝[insert y s] x
Module: Mathlib.Topology.VectorBundle.Basic

Goal state before:
pp: R : Type u_1
B : Type u_2
F : Type u_3
inst✝³ : NontriviallyNormedField R
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace R F
inst✝ : TopologicalSpace B
ι : Type u_5
Z : VectorBundleCore R B F ι
b : B
a : F
⊢ { proj := b, snd := a } ∈ (Z.localTriv (Z.indexAt b)).source

Tactic:
mem_localTriv_source

Goal state after:
R : Type u_1
B : Type u_2
F : Type u_3
inst✝³ : NontriviallyNormedField R
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace R F
inst✝ : TopologicalSpace B
ι : Type u_5
Z : VectorBundleCore R B F ι
b : B
a : F
⊢ { proj := b, snd := a }.proj ∈ Z.baseSet (Z.indexAt b)
Module: Mathlib.Geometry.Manifold.MFDeriv.SpecificFunctions

Goal state before:
pp: 𝕜 : Type u_1
inst✝¹⁰ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
E' : Type u_5
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝² : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝¹ : TopologicalSpace M'
inst✝ : ChartedSpace H' M'
x : M × M'
⊢ ∀ᶠ (y : E × E') in 𝓝[range ↑(I.prod I')] ↑(extChartAt (I.prod I') x) x,
    (↑(extChartAt I x.1) ∘ Prod.fst ∘ ↑(extChartAt (I.prod I') x).symm) y = y.1

Tactic:
filter_upwards [extChartAt_target_mem_nhdsWithin x] with y hy

Goal state after:
𝕜 : Type u_1
inst✝¹⁰ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
E' : Type u_5
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝² : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝¹ : TopologicalSpace M'
inst✝ : ChartedSpace H' M'
x : M × M'
y : E × E'
hy : y ∈ (extChartAt (I.prod I') x).target
⊢ (↑(extChartAt I x.1) ∘ Prod.fst ∘ ↑(extChartAt (I.prod I') x).symm) y = y.1
Module: Mathlib.Geometry.Manifold.VectorBundle.Basic

Goal state before:
pp: n : ℕ∞ω
𝕜 : Type u_1
B : Type u_2
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁵ : NontriviallyNormedField 𝕜
inst✝¹⁴ : NormedAddCommGroup F
inst✝¹³ : NormedSpace 𝕜 F
inst✝¹² : TopologicalSpace (TotalSpace F E)
inst✝¹¹ : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹⁰ : NormedAddCommGroup EB
inst✝⁹ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁸ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
EM : Type u_10
inst✝⁷ : NormedAddCommGroup EM
inst✝⁶ : NormedSpace 𝕜 EM
HM : Type u_11
inst✝⁵ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝⁴ : TopologicalSpace M
inst✝³ : ChartedSpace HM M
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
f : M → TotalSpace F E
s : Set M
x₀ : M
hf : ContinuousWithinAt f s x₀
⊢ ContMDiffWithinAt IM 𝓘(𝕜, EB × F) n (↑(extChartAt (IB.prod 𝓘(𝕜, F)) (f x₀)) ∘ f) s x₀ ↔
    ContMDiffWithinAt IM 𝓘(𝕜, EB) n (↑(extChartAt IB (f x₀).proj) ∘ fun x ↦ (f x).proj) s x₀ ∧
      ContMDiffWithinAt IM 𝓘(𝕜, F) n
        (↑(extChartAt 𝓘(𝕜, F) (↑(trivializationAt F E (f x₀).proj) (f x₀)).2) ∘ fun x ↦
          (↑(trivializationAt F E (f x₀).proj) (f x)).2)
        s x₀

Tactic:
simp_rw +instances [modelWithCornersSelf_prod, FiberBundle.extChartAt, Function.comp_def,
    PartialEquiv.trans_apply, PartialEquiv.prod_coe, PartialEquiv.refl_coe,
    extChartAt_self_apply, modelWithCornersSelf_coe, Function.id_def, ← chartedSpaceSelf_prod]

Goal state after:
n : ℕ∞ω
𝕜 : Type u_1
B : Type u_2
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁵ : NontriviallyNormedField 𝕜
inst✝¹⁴ : NormedAddCommGroup F
inst✝¹³ : NormedSpace 𝕜 F
inst✝¹² : TopologicalSpace (TotalSpace F E)
inst✝¹¹ : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹⁰ : NormedAddCommGroup EB
inst✝⁹ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁸ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
EM : Type u_10
inst✝⁷ : NormedAddCommGroup EM
inst✝⁶ : NormedSpace 𝕜 EM
HM : Type u_11
inst✝⁵ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝⁴ : TopologicalSpace M
inst✝³ : ChartedSpace HM M
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
f : M → TotalSpace F E
s : Set M
x₀ : M
hf : ContinuousWithinAt f s x₀
⊢ ContMDiffWithinAt IM (𝓘(𝕜, EB).prod 𝓘(𝕜, F)) n
      (fun x ↦
        (↑(extChartAt IB (f x₀).proj) (↑(trivializationAt F E (f x₀).proj).toPartialEquiv (f x)).1,
          (↑(trivializationAt F E (f x₀).proj).toPartialEquiv (f x)).2))
      s x₀ ↔
    ContMDiffWithinAt IM 𝓘(𝕜, EB) n (fun x ↦ ↑(extChartAt IB (f x₀).proj) (f x).proj) s x₀ ∧
      ContMDiffWithinAt IM 𝓘(𝕜, F) n (fun x ↦ (↑(trivializationAt F E (f x₀).proj) (f x)).2) s x₀
Module: Mathlib.Geometry.Manifold.MFDeriv.SpecificFunctions

Goal state before:
pp: 𝕜 : Type u_1
inst✝¹⁰ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
E' : Type u_5
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝² : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝¹ : TopologicalSpace M'
inst✝ : ChartedSpace H' M'
x : M × M'
⊢ ∀ᶠ (y : E × E') in 𝓝[range ↑(I.prod I')] ↑(extChartAt (I.prod I') x) x,
    (↑(extChartAt I' x.2) ∘ Prod.snd ∘ ↑(extChartAt (I.prod I') x).symm) y = y.2

Tactic:
filter_upwards [extChartAt_target_mem_nhdsWithin x] with y hy

Goal state after:
𝕜 : Type u_1
inst✝¹⁰ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
E' : Type u_5
inst✝⁴ : NormedAddCommGroup E'
inst✝³ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝² : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝¹ : TopologicalSpace M'
inst✝ : ChartedSpace H' M'
x : M × M'
y : E × E'
hy : y ∈ (extChartAt (I.prod I') x).target
⊢ (↑(extChartAt I' x.2) ∘ Prod.snd ∘ ↑(extChartAt (I.prod I') x).symm) y = y.2
Module: Mathlib.Geometry.Manifold.VectorBundle.Tangent

Goal state before:
pp: case refine_2
𝕜 : Type u_1
inst✝⁵ : NontriviallyNormedField 𝕜
n : ℕ∞ω
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
H : Type u_4
inst✝² : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_6
inst✝¹ : TopologicalSpace M
inst✝ : ChartedSpace H M
h : IsManifold I (n + 1) M
this : IsManifold I n M
i j : ↑(atlas H M)
⊢ ↑((↑i).extend I) '' ((tangentBundleCore I M).baseSet i ∩ (tangentBundleCore I M).baseSet j) ⊆
    (((↑i).extend I).symm ≫ (↑j).extend I).source

Tactic:
· exact (i.1.extend_image_source_inter j.1).subset

Goal state after:
Module: Mathlib.Geometry.Manifold.MFDeriv.SpecificFunctions

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁷ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁴ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝³ : TopologicalSpace M
inst✝² : ChartedSpace H M
s : Set M
z : M
F' : Type u_21
inst✝¹ : NormedRing F'
inst✝ : NormedAlgebra 𝕜 F'
p : M → F'
hp : MDiffAt[s] p z
n : ℕ
⊢ MDiffAt[s] (p ^ n) z

Tactic:
induction n with
  | zero => simpa [pow_zero] using! mdifferentiableWithinAt_const
  | succ n hn => simpa [pow_succ] using! hn.mul hp

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

Goal state before:
pp: α : Type u_1
inst✝ : PseudoEMetricSpace α
pow_pos : ∀ (k : ℕ), 0 < 2⁻¹ ^ k
hpow_le : ∀ {m n : ℕ}, m ≤ n → 2⁻¹ ^ n ≤ 2⁻¹ ^ m
h2pow : ∀ (n : ℕ), 2 * 2⁻¹ ^ (n + 1) = 2⁻¹ ^ n
ι : Type u_1
s : ι → Set α
ho : ∀ (a : ι), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (s a)
hcov : ⋃ a, s a = univ
⊢ ∃ β t,
    (∀ (b : β), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (t b)) ∧
      ⋃ b, t b = univ ∧ LocallyFinite t ∧ ∀ (b : β), ∃ a, t b ⊆ s a

Tactic:
simp only [iUnion_eq_univ_iff] at hcov

Goal state after:
α : Type u_1
inst✝ : PseudoEMetricSpace α
pow_pos : ∀ (k : ℕ), 0 < 2⁻¹ ^ k
hpow_le : ∀ {m n : ℕ}, m ≤ n → 2⁻¹ ^ n ≤ 2⁻¹ ^ m
h2pow : ∀ (n : ℕ), 2 * 2⁻¹ ^ (n + 1) = 2⁻¹ ^ n
ι : Type u_1
s : ι → Set α
ho : ∀ (a : ι), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (s a)
hcov : ∀ (x : α), ∃ i, x ∈ s i
⊢ ∃ β t,
    (∀ (b : β), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (t b)) ∧
      ⋃ b, t b = univ ∧ LocallyFinite t ∧ ∀ (b : β), ∃ a, t b ⊆ s a
Module: Mathlib.Topology.EMetricSpace.Paracompact

Goal state before:
pp: α : Type u_1
inst✝ : PseudoEMetricSpace α
pow_pos : ∀ (k : ℕ), 0 < 2⁻¹ ^ k
hpow_le : ∀ {m n : ℕ}, m ≤ n → 2⁻¹ ^ n ≤ 2⁻¹ ^ m
h2pow : ∀ (n : ℕ), 2 * 2⁻¹ ^ (n + 1) = 2⁻¹ ^ n
ι : Type u_1
s : ι → Set α
ho : ∀ (a : ι), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (s a)
hcov : ∀ (x : α), ∃ i, x ∈ s i
w✝ : LinearOrder ι
wf : WellFoundedLT ι
ind : α → ι := fun x ↦ ⋯.min {i | x ∈ s i} ⋯
mem_ind : ∀ (x : α), x ∈ s (ind x)
notMem_of_lt_ind : ∀ {x : α} {i : ι}, i < ind x → x ∈ s i → False
D : ℕ → ι → Set α :=
  fun t ↦
    Nat.strongRec (motive := fun x ↦ ι → Set α)
      (fun n D' i ↦
        ⋃ x,
          ⋃ (_ : ind x = i),
            ⋃ (_ : eball x (3 * 2⁻¹ ^ n) ⊆ s i), ⋃ (_ : ∀ (m : ℕ) (H : m < n) (j : ι), x ∉ D' m H j), eball x (2⁻¹ ^ n))
      t
hD :
  D = fun t ↦
    Nat.strongRec (motive := fun x ↦ ι → Set α)
      (fun n D' i ↦
        ⋃ x,
          ⋃ (_ : ind x = i),
            ⋃ (_ : eball x (3 * 2⁻¹ ^ n) ⊆ s i), ⋃ (_ : ∀ (m : ℕ) (H : m < n) (j : ι), x ∉ D' m H j), eball x (2⁻¹ ^ n))
      t
Dn :
  ∀ (n : ℕ) (i : ι),
    D n i =
      ⋃ x,
        ⋃ (_ : ind x = i), ⋃ (_ : eball x (3 * 2⁻¹ ^ n) ⊆ s i), ⋃ (_ : ∀ m < n, ∀ (j : ι), x ∉ D m j), eball x (2⁻¹ ^ n)
⊢ ∃ β t,
    (∀ (b : β), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (t b)) ∧
      ⋃ b, t b = univ ∧ LocallyFinite t ∧ ∀ (b : β), ∃ a, t b ⊆ s a

Tactic:
have memD {n i y} :
      y ∈ D n i ↔ ∃ x : α, ind x = i ∧ eball x (3 * 2⁻¹ ^ n) ⊆ s i ∧
        (∀ m < n, ∀ (j : ι), x ∉ D m j) ∧ edist y x < 2⁻¹ ^ n := by
    rw [Dn n i]
    simp only [mem_iUnion, mem_eball, exists_prop]

Goal state after:
α : Type u_1
inst✝ : PseudoEMetricSpace α
pow_pos : ∀ (k : ℕ), 0 < 2⁻¹ ^ k
hpow_le : ∀ {m n : ℕ}, m ≤ n → 2⁻¹ ^ n ≤ 2⁻¹ ^ m
h2pow : ∀ (n : ℕ), 2 * 2⁻¹ ^ (n + 1) = 2⁻¹ ^ n
ι : Type u_1
s : ι → Set α
ho : ∀ (a : ι), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (s a)
hcov : ∀ (x : α), ∃ i, x ∈ s i
w✝ : LinearOrder ι
wf : WellFoundedLT ι
ind : α → ι := fun x ↦ ⋯.min {i | x ∈ s i} ⋯
mem_ind : ∀ (x : α), x ∈ s (ind x)
notMem_of_lt_ind : ∀ {x : α} {i : ι}, i < ind x → x ∈ s i → False
D : ℕ → ι → Set α :=
  fun t ↦
    Nat.strongRec (motive := fun x ↦ ι → Set α)
      (fun n D' i ↦
        ⋃ x,
          ⋃ (_ : ind x = i),
            ⋃ (_ : eball x (3 * 2⁻¹ ^ n) ⊆ s i), ⋃ (_ : ∀ (m : ℕ) (H : m < n) (j : ι), x ∉ D' m H j), eball x (2⁻¹ ^ n))
      t
hD :
  D = fun t ↦
    Nat.strongRec (motive := fun x ↦ ι → Set α)
      (fun n D' i ↦
        ⋃ x,
          ⋃ (_ : ind x = i),
            ⋃ (_ : eball x (3 * 2⁻¹ ^ n) ⊆ s i), ⋃ (_ : ∀ (m : ℕ) (H : m < n) (j : ι), x ∉ D' m H j), eball x (2⁻¹ ^ n))
      t
Dn :
  ∀ (n : ℕ) (i : ι),
    D n i =
      ⋃ x,
        ⋃ (_ : ind x = i), ⋃ (_ : eball x (3 * 2⁻¹ ^ n) ⊆ s i), ⋃ (_ : ∀ m < n, ∀ (j : ι), x ∉ D m j), eball x (2⁻¹ ^ n)
memD :
  ∀ {n : ℕ} {i : ι} {y : α},
    y ∈ D n i ↔ ∃ x, ind x = i ∧ eball x (3 * 2⁻¹ ^ n) ⊆ s i ∧ (∀ m < n, ∀ (j : ι), x ∉ D m j) ∧ edist y x < 2⁻¹ ^ n
⊢ ∃ β t,
    (∀ (b : β), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (t b)) ∧
      ⋃ b, t b = univ ∧ LocallyFinite t ∧ ∀ (b : β), ∃ a, t b ⊆ s a
Module: Mathlib.MeasureTheory.Function.AEEqOfIntegral

Goal state before:
pp: α : Type u_1
E : Type u_2
𝕜 : Type u_3
m : MeasurableSpace α
μ : Measure α
inst✝² : RCLike 𝕜
inst✝¹ : NormedAddCommGroup E
inst✝ : NormedSpace 𝕜 E
t : Set E
f : α → E
hf : ∀ (c : StrongDual 𝕜 E), (fun x ↦ c (f x)) =ᵐ[μ] 0
h't : ∀ᵐ (x : α) ∂μ, f x ∈ t
d : Set E
d_count : d.Countable
hd : t ⊆ closure[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] d
this : Encodable ↑d
s : ↑d → StrongDual 𝕜 E
hs : ∀ (x : ↑d), ‖s x‖ ≤ 1 ∧ (s x) ↑x = ↑‖↑x‖
a : E
hat : a ∈ t
ha : a ≠ 0
⊢ 0 < ‖a‖

Tactic:
simp only [ha, norm_pos_iff, Ne, not_false_iff]

Goal state after:
Module: Mathlib.Analysis.Distribution.AEEqOfIntegralContDiff

Goal state before:
pp: case pos
E : Type u_1
inst✝¹³ : NormedAddCommGroup E
inst✝¹² : NormedSpace ℝ E
inst✝¹¹ : FiniteDimensional ℝ E
F : Type u_2
inst✝¹⁰ : NormedAddCommGroup F
inst✝⁹ : NormedSpace ℝ F
inst✝⁸ : CompleteSpace F
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
inst✝⁴ : IsManifold I ∞ M
inst✝³ : MeasurableSpace M
inst✝² : BorelSpace M
inst✝¹ : T2Space M
f : M → F
μ : Measure M
inst✝ : SigmaCompactSpace M
hf : LocallyIntegrable f μ
h : ∀ (g : M → ℝ), ContMDiff I 𝓘(ℝ, ℝ) ∞ g → HasCompactSupport g → ∫ (x : M), g x • f x ∂μ = 0
this✝² : LocallyCompactSpace H
this✝¹ : LocallyCompactSpace M
this✝ : SecondCountableTopology H
this : SecondCountableTopology M
x✝ : MetricSpace M := metrizableSpaceMetric M
s : Set M
hs : IsCompact s
δ : ℝ
δpos : 0 < δ
hδ : IsCompact (cthickening δ s)
u : ℕ → ℝ
u_pos : ∀ (n : ℕ), u n ∈ Ioo 0 δ
u_lim : Tendsto u atTop (𝓝 0)
v : ℕ → Set M := fun n ↦ thickening (u n) s
K : Set M
K_compact : IsCompact K
vK : ∀ (n : ℕ), v n ⊆ K
g : ℕ → M → ℝ
g_supp : ∀ (n : ℕ), support (g n) = v n
g_diff : ∀ (n : ℕ), ContMDiff I 𝓘(ℝ, ℝ) ∞ (g n)
g_range : ∀ (n : ℕ), range (g n) ⊆ Icc 0 1
hg : ∀ (n : ℕ), ∀ x ∈ s, g n x = 1
bound : M → ℝ := K.indicator fun x ↦ ‖f x‖
A : ∀ (n : ℕ), AEStronglyMeasurable (fun x ↦ g n x • f x) μ
B : Integrable bound μ
C : ∀ (n : ℕ), ∀ᵐ (x : M) ∂μ, ‖g n x • f x‖ ≤ bound x
x : M
hxs : x ∈ s
⊢ Tendsto (fun n ↦ g n x • f x) atTop (𝓝 (s.indicator f x))

Tactic:
have : ∀ n, g n x = 1 := fun n ↦ hg n x hxs

Goal state after:
case pos
E : Type u_1
inst✝¹³ : NormedAddCommGroup E
inst✝¹² : NormedSpace ℝ E
inst✝¹¹ : FiniteDimensional ℝ E
F : Type u_2
inst✝¹⁰ : NormedAddCommGroup F
inst✝⁹ : NormedSpace ℝ F
inst✝⁸ : CompleteSpace F
H : Type u_3
inst✝⁷ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type u_4
inst✝⁶ : TopologicalSpace M
inst✝⁵ : ChartedSpace H M
inst✝⁴ : IsManifold I ∞ M
inst✝³ : MeasurableSpace M
inst✝² : BorelSpace M
inst✝¹ : T2Space M
f : M → F
μ : Measure M
inst✝ : SigmaCompactSpace M
hf : LocallyIntegrable f μ
h : ∀ (g : M → ℝ), ContMDiff I 𝓘(ℝ, ℝ) ∞ g → HasCompactSupport g → ∫ (x : M), g x • f x ∂μ = 0
this✝³ : LocallyCompactSpace H
this✝² : LocallyCompactSpace M
this✝¹ : SecondCountableTopology H
this✝ : SecondCountableTopology M
x✝ : MetricSpace M := metrizableSpaceMetric M
s : Set M
hs : IsCompact s
δ : ℝ
δpos : 0 < δ
hδ : IsCompact (cthickening δ s)
u : ℕ → ℝ
u_pos : ∀ (n : ℕ), u n ∈ Ioo 0 δ
u_lim : Tendsto u atTop (𝓝 0)
v : ℕ → Set M := fun n ↦ thickening (u n) s
K : Set M
K_compact : IsCompact K
vK : ∀ (n : ℕ), v n ⊆ K
g : ℕ → M → ℝ
g_supp : ∀ (n : ℕ), support (g n) = v n
g_diff : ∀ (n : ℕ), ContMDiff I 𝓘(ℝ, ℝ) ∞ (g n)
g_range : ∀ (n : ℕ), range (g n) ⊆ Icc 0 1
hg : ∀ (n : ℕ), ∀ x ∈ s, g n x = 1
bound : M → ℝ := K.indicator fun x ↦ ‖f x‖
A : ∀ (n : ℕ), AEStronglyMeasurable (fun x ↦ g n x • f x) μ
B : Integrable bound μ
C : ∀ (n : ℕ), ∀ᵐ (x : M) ∂μ, ‖g n x • f x‖ ≤ bound x
x : M
hxs : x ∈ s
this : ∀ (n : ℕ), g n x = 1
⊢ Tendsto (fun n ↦ g n x • f x) atTop (𝓝 (s.indicator f x))
Module: Mathlib.MeasureTheory.Function.AEEqOfIntegral

Goal state before:
pp: α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
f : α → ℝ
hf : AEFinStronglyMeasurable f μ
hf_int_finite : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → IntegrableOn f s μ
hf_zero : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → 0 ≤ ∫ (x : α) in s, f x ∂μ
⊢ 0 ≤ᵐ[μ] f

Tactic:
let t := hf.sigmaFiniteSet

Goal state after:
α : Type u_1
m0 : MeasurableSpace α
μ : Measure α
f : α → ℝ
hf : AEFinStronglyMeasurable f μ
hf_int_finite : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → IntegrableOn f s μ
hf_zero : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → 0 ≤ ∫ (x : α) in s, f x ∂μ
t : Set α := hf.sigmaFiniteSet
⊢ 0 ≤ᵐ[μ] f
Module: Mathlib.MeasureTheory.Function.AEEqOfIntegral

Goal state before:
pp: α : Type u_1
E : Type u_2
m0 : MeasurableSpace α
μ : Measure α
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : CompleteSpace E
f : α → E
hf_int_finite : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → IntegrableOn f s μ
hf_zero : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → ∫ (x : α) in s, f x ∂μ = 0
hf : AEFinStronglyMeasurable f μ
⊢ f =ᵐ[μ] 0

Tactic:
let t := hf.sigmaFiniteSet

Goal state after:
α : Type u_1
E : Type u_2
m0 : MeasurableSpace α
μ : Measure α
inst✝² : NormedAddCommGroup E
inst✝¹ : NormedSpace ℝ E
inst✝ : CompleteSpace E
f : α → E
hf_int_finite : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → IntegrableOn f s μ
hf_zero : ∀ (s : Set α), MeasurableSet s → μ s < ∞ → ∫ (x : α) in s, f x ∂μ = 0
hf : AEFinStronglyMeasurable f μ
t : Set α := hf.sigmaFiniteSet
⊢ f =ᵐ[μ] 0
Module: Mathlib.Analysis.Calculus.Rademacher

Goal state before:
pp: case neg
E : Type u_1
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : MeasurableSpace E
inst✝² : BorelSpace E
C : ℝ≥0
f g : E → ℝ
μ : Measure E
inst✝¹ : FiniteDimensional ℝ E
inst✝ : μ.IsAddHaarMeasure
hf : LipschitzWith C f
h'f : HasCompactSupport f
hg : Continuous[PseudoMetricSpace.toUniformSpace.toTopologicalSpace, _] g
v : E
K : Set E := cthickening ‖v‖ (tsupport f)
K_compact : IsCompact K
t : ℝ
ht : t ∈ Ioc 0 1
t_pos : 0 < t
x : E
hx : x ∉ K
⊢ ‖t⁻¹ • (f (x + t • v) - f x) * g x‖ ≤ K.indicator (fun x ↦ ↑C * ‖v‖ * ‖g x‖) x

Tactic:
· have A : f x = 0 := by
        rw [← Function.notMem_support]
        contrapose hx
        exact self_subset_cthickening _ (subset_tsupport _ hx)
      have B : f (x + t • v) = 0 := by
        rw [← Function.notMem_support]
        contrapose hx
        apply mem_cthickening_of_dist_le _ _ (‖v‖) (tsupport f) (subset_tsupport _ hx)
        simp only [dist_eq_norm, sub_add_cancel_left, norm_neg, norm_smul, Real.norm_eq_abs,
          abs_of_nonneg t_pos.le]
        exact mul_le_of_le_one_left (norm_nonneg v) ht.2
      simp only [B, A, _root_.sub_self, smul_eq_mul, mul_zero, zero_mul, norm_zero]
      exact indicator_nonneg (fun y _hy ↦ by positivity) _

Goal state after:
Module: Mathlib.MeasureTheory.Integral.IntervalIntegral.AbsolutelyContinuousFun

Goal state before:
pp: F : Type u_2
inst✝¹ : NormedAddCommGroup F
inst✝ : NormedSpace ℝ F
f f' : ℝ → F
d b η : ℝ
hdb✝ : d ≤ b
hf : ∀ᵐ (x : ℝ), x ∈ Ioo d b → HasDerivAt f (f' x) x
hη : 0 < η
hdb : d < b
t : Set (ℝ × ℝ) := {z | (d < z.1 ∧ z.1 < z.2 ∧ z.2 < b) ∧ dist (slope f z.1 z.2) (f' z.1) < η}
s : Set ℝ := {x | x ∈ Ioo d b ∧ HasDerivAt f (f' x) x}
x : ℝ
hx : x ∈ s
this : Tendsto (slope f x) (𝓝[≠] x) (𝓝 (f' x))
δ : ℝ
hδ₁ : δ > 0
hδ₂ : ∀ ⦃x_1 : ℝ⦄, x_1 ∈ {x}ᶜ → dist x_1 x < δ → dist (slope f x x_1) (f' x) < η
evn_bound : ∀ {α : ℝ}, 0 < α → ∀ᶠ (ε : ℝ) in 𝓝[>] 0, ε < α
evn_pos : ∀ᶠ (ε : ℝ) in 𝓝[>] 0, 0 < ε
ε : ℝ
hε₁ : 0 < ε
hε₂ : ε < η
hε₃ : ε < δ
hε₄ : ε < (b - x) / 2
⊢ dist (slope f (x, x + ε).1 (x, x + ε).2) (f' (x, x + ε).1) < η

Tactic:
exact hδ₂ (by grind) (by simp [abs_eq_self.mpr hε₁.le, hε₃])

Goal state after: