mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Geometry.Manifold.ContMDiff.Atlas

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁸ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁷ : NormedAddCommGroup E
inst✝⁶ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁵ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁴ : TopologicalSpace M
inst✝³ : ChartedSpace H M
n : ℕ∞ω
M' : Type u_5
inst✝² : TopologicalSpace M'
inst✝¹ : IsManifold I n M
inst✝ : ChartedSpace H M'
IsM' : IsManifold I n M'
f : OpenPartialHomeomorph M M'
h : LiftPropOn (contDiffGroupoid n I).IsLocalStructomorphWithinAt (↑f) f.source
X : M'
hX : X ∈ f.symm.source
x : M := ↑f.symm X
hx : x ∈ f.source
c : OpenPartialHomeomorph M H := chartAt H x
c' : OpenPartialHomeomorph M' H := chartAt H X
hxf :
  (contDiffGroupoid n I).IsLocalStructomorphWithinAt (↑(chartAt H (↑f x)) ∘ ↑f ∘ ↑(chartAt H x).symm)
    (↑(chartAt H x).symm ⁻¹' f.source) (↑(chartAt H x) x)
h2x : ↑(chartAt H X) X ∈ ↑(chartAt H X).symm ⁻¹' f.symm.source
e : OpenPartialHomeomorph H H
he : e ∈ contDiffGroupoid n I
h2e : e.source ⊆ (c.symm ≫ₕ f ≫ₕ c').source
hef : EqOn (↑c' ∘ ↑f ∘ ↑c.symm) (↑e) e.source
hex : ↑c x ∈ e.source
h2X : ↑c' X = ↑e (↑c (↑f.symm X))
⊢ EqOn (↑c ∘ ↑f.symm ∘ ↑c'.symm) (↑e.symm) (↑c'.symm ⁻¹' f.target ∩ e.target)

Tactic:
have h1 : EqOn (c.symm ≫ₕ f ≫ₕ c').symm e.symm (e.target ∩ e.target) := by
        apply EqOn.symm
        refine e.isImage_source_target.symm_eqOn_of_inter_eq_of_eqOn ?_ ?_
        · rw [inter_self, inter_eq_right.mpr h2e]
        · rw [inter_self]; exact hef.symm

Goal state after:
𝕜 : Type u_1
inst✝⁸ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁷ : NormedAddCommGroup E
inst✝⁶ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁵ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁴ : TopologicalSpace M
inst✝³ : ChartedSpace H M
n : ℕ∞ω
M' : Type u_5
inst✝² : TopologicalSpace M'
inst✝¹ : IsManifold I n M
inst✝ : ChartedSpace H M'
IsM' : IsManifold I n M'
f : OpenPartialHomeomorph M M'
h : LiftPropOn (contDiffGroupoid n I).IsLocalStructomorphWithinAt (↑f) f.source
X : M'
hX : X ∈ f.symm.source
x : M := ↑f.symm X
hx : x ∈ f.source
c : OpenPartialHomeomorph M H := chartAt H x
c' : OpenPartialHomeomorph M' H := chartAt H X
hxf :
  (contDiffGroupoid n I).IsLocalStructomorphWithinAt (↑(chartAt H (↑f x)) ∘ ↑f ∘ ↑(chartAt H x).symm)
    (↑(chartAt H x).symm ⁻¹' f.source) (↑(chartAt H x) x)
h2x : ↑(chartAt H X) X ∈ ↑(chartAt H X).symm ⁻¹' f.symm.source
e : OpenPartialHomeomorph H H
he : e ∈ contDiffGroupoid n I
h2e : e.source ⊆ (c.symm ≫ₕ f ≫ₕ c').source
hef : EqOn (↑c' ∘ ↑f ∘ ↑c.symm) (↑e) e.source
hex : ↑c x ∈ e.source
h2X : ↑c' X = ↑e (↑c (↑f.symm X))
h1 : EqOn (↑(c.symm ≫ₕ f ≫ₕ c').symm) (↑e.symm) (e.target ∩ e.target)
⊢ EqOn (↑c ∘ ↑f.symm ∘ ↑c'.symm) (↑e.symm) (↑c'.symm ⁻¹' f.target ∩ e.target)
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)
⊢ ContinuousOn (invFun' e₁ e₂) ((e₁.baseSet ∩ e₂.baseSet) ×ˢ univ)

Tactic:
rw [(Prod.isInducing_diag F₁ E₁ F₂ E₂).continuousOn_iff]
  have H₁ : Continuous fun p : B × F₁ × F₂ ↦ ((p.1, p.2.1), (p.1, p.2.2)) := by fun_prop
  refine (e₁.continuousOn_symm.prodMap e₂.continuousOn_symm).comp H₁.continuousOn ?_
  exact fun x h ↦ ⟨⟨h.1.1, mem_univ _⟩, ⟨h.1.2, mem_univ _⟩⟩

Goal state after:
Module: Mathlib.Topology.VectorBundle.Basic

Goal state before:
pp: R : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
inst✝⁷ : Semiring R
inst✝⁶ : TopologicalSpace F
inst✝⁵ : TopologicalSpace B
inst✝⁴ : AddCommMonoid F
inst✝³ : Module R F
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module R (E x)
e : Pretrivialization F TotalSpace.proj
inst✝ : Pretrivialization.IsLinear R e
b : B
hb : b ∈ e.baseSet
⊢ ⇑(Pretrivialization.linearMapAt R e b) = fun y ↦ (↑e { proj := b, snd := y }).2

Tactic:
coe_linearMapAt,

Goal state after:
R : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
inst✝⁷ : Semiring R
inst✝⁶ : TopologicalSpace F
inst✝⁵ : TopologicalSpace B
inst✝⁴ : AddCommMonoid F
inst✝³ : Module R F
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module R (E x)
e : Pretrivialization F TotalSpace.proj
inst✝ : Pretrivialization.IsLinear R e
b : B
hb : b ∈ e.baseSet
⊢ (fun y ↦ if b ∈ e.baseSet then (↑e { proj := b, snd := y }).2 else 0) = fun y ↦ (↑e { proj := b, snd := y }).2
Module: Mathlib.Topology.VectorBundle.Basic

Goal state before:
pp: R : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
inst✝⁸ : Semiring R
inst✝⁷ : TopologicalSpace F
inst✝⁶ : TopologicalSpace B
inst✝⁵ : TopologicalSpace (TotalSpace F E)
inst✝⁴ : AddCommMonoid F
inst✝³ : Module R F
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module R (E x)
e : Trivialization F TotalSpace.proj
inst✝ : Trivialization.IsLinear R e
b : B
hb : b ∈ e.baseSet
⊢ ⇑(Trivialization.linearMapAt R e b) = fun y ↦ (↑e { proj := b, snd := y }).2

Tactic:
coe_linearMapAt,

Goal state after:
R : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
inst✝⁸ : Semiring R
inst✝⁷ : TopologicalSpace F
inst✝⁶ : TopologicalSpace B
inst✝⁵ : TopologicalSpace (TotalSpace F E)
inst✝⁴ : AddCommMonoid F
inst✝³ : Module R F
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module R (E x)
e : Trivialization F TotalSpace.proj
inst✝ : Trivialization.IsLinear R e
b : B
hb : b ∈ e.baseSet
⊢ (fun y ↦ if b ∈ e.baseSet then (↑e { proj := b, snd := y }).2 else 0) = fun y ↦ (↑e { proj := b, snd := y }).2
Module: Mathlib.Geometry.Manifold.MFDeriv.Basic

Goal state before:
pp: case inl
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)
this✝ : T1Space M
hf :
  ContinuousWithinAt f s x ∧
    HasFDerivWithinAt (writtenInExtChartAt I I' x f) f' (↑(extChartAt I x).symm ⁻¹' s ∩ range ↑I) (↑(extChartAt I x) x)
this : (extChartAt I x).target ∈ 𝓝[↑(extChartAt I x).symm ⁻¹' insert x s ∩ range ↑I] ↑(extChartAt I x) x
z : E
h'z : z ∈ (extChartAt I x).target
hz : z ∈ ↑(extChartAt I x).symm ⁻¹' insert x s
h2z : z ∈ range ↑I
⊢ z ∈ insert (↑(extChartAt I x) x) (↑(extChartAt I x).symm ⁻¹' s ∩ range ↑I)

Tactic:
simp only [mem_inter_iff, mem_preimage, mem_insert_iff, mem_range] at hz h2z ⊢

Goal state after:
case inl
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)
this✝ : T1Space M
hf :
  ContinuousWithinAt f s x ∧
    HasFDerivWithinAt (writtenInExtChartAt I I' x f) f' (↑(extChartAt I x).symm ⁻¹' s ∩ range ↑I) (↑(extChartAt I x) x)
this : (extChartAt I x).target ∈ 𝓝[↑(extChartAt I x).symm ⁻¹' insert x s ∩ range ↑I] ↑(extChartAt I x) x
z : E
h'z : z ∈ (extChartAt I x).target
hz : ↑(extChartAt I x).symm z = x ∨ ↑(extChartAt I x).symm z ∈ s
h2z : ∃ y, ↑I y = z
⊢ z = ↑(extChartAt I x) x ∨ ↑(extChartAt I x).symm z ∈ s ∧ ∃ y, ↑I y = z
Module: Mathlib.Geometry.Manifold.MFDeriv.SpecificFunctions

Goal state before:
pp: 𝕜 : Type u_1
inst✝¹⁵ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹⁴ : NormedAddCommGroup E
inst✝¹³ : NormedSpace 𝕜 E
H : Type u_3
inst✝¹² : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝¹¹ : TopologicalSpace M
inst✝¹⁰ : ChartedSpace H M
E' : Type u_5
inst✝⁹ : NormedAddCommGroup E'
inst✝⁸ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝⁷ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝⁶ : TopologicalSpace M'
inst✝⁵ : ChartedSpace H' M'
E'' : Type u_8
inst✝⁴ : NormedAddCommGroup E''
inst✝³ : NormedSpace 𝕜 E''
H'' : Type u_9
inst✝² : TopologicalSpace H''
I'' : ModelWithCorners 𝕜 E'' H''
M'' : Type u_10
inst✝¹ : TopologicalSpace M''
inst✝ : ChartedSpace H'' M''
x : M
f : M → M'
g : M → M''
hf : MDiffAt f x
hg : MDiffAt g x
⊢ (mfderiv% fun x ↦ (f x, g x)) x = (mfderiv% f x).prod (mfderiv% g x)

Tactic:
by
  simp_rw [← mfderivWithin_univ]
  exact mfderivWithin_prodMk hf.mdifferentiableWithinAt hg.mdifferentiableWithinAt
    (uniqueMDiffWithinAt_univ I)

Goal state after:
Module: Mathlib.Geometry.Manifold.VectorBundle.Tangent

Goal state before:
pp: 𝕜 : Type u_1
inst✝¹⁴ : NontriviallyNormedField 𝕜
n : ℕ∞ω
E : Type u_2
inst✝¹³ : NormedAddCommGroup E
inst✝¹² : NormedSpace 𝕜 E
E' : Type u_3
inst✝¹¹ : NormedAddCommGroup E'
inst✝¹⁰ : NormedSpace 𝕜 E'
H : Type u_4
inst✝⁹ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
H' : Type u_5
inst✝⁸ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M : Type u_6
inst✝⁷ : TopologicalSpace M
inst✝⁶ : ChartedSpace H M
M' : Type u_7
inst✝⁵ : TopologicalSpace M'
inst✝⁴ : ChartedSpace H' M'
F : Type u_8
inst✝³ : NormedAddCommGroup F
inst✝² : NormedSpace 𝕜 F
inst✝¹ : IsManifold I 1 M
inst✝ : IsManifold I' 1 M'
p : TangentBundle I H := ⟨↑I.symm 0, 0⟩
⊢ Continuous[_, instTopologicalSpaceModelProd H E] (TotalSpace.toProd H E).toFun

Tactic:
have : Continuous (chartAt (ModelProd H E) p) := by
        rw [← continuousOn_univ]
        convert! (chartAt (ModelProd H E) p).continuousOn
        simp only [mfld_simps]

Goal state after:
𝕜 : Type u_1
inst✝¹⁴ : NontriviallyNormedField 𝕜
n : ℕ∞ω
E : Type u_2
inst✝¹³ : NormedAddCommGroup E
inst✝¹² : NormedSpace 𝕜 E
E' : Type u_3
inst✝¹¹ : NormedAddCommGroup E'
inst✝¹⁰ : NormedSpace 𝕜 E'
H : Type u_4
inst✝⁹ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
H' : Type u_5
inst✝⁸ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M : Type u_6
inst✝⁷ : TopologicalSpace M
inst✝⁶ : ChartedSpace H M
M' : Type u_7
inst✝⁵ : TopologicalSpace M'
inst✝⁴ : ChartedSpace H' M'
F : Type u_8
inst✝³ : NormedAddCommGroup F
inst✝² : NormedSpace 𝕜 F
inst✝¹ : IsManifold I 1 M
inst✝ : IsManifold I' 1 M'
p : TangentBundle I H := ⟨↑I.symm 0, 0⟩
this : Continuous[_, instTopologicalSpaceModelProd H E] ↑(chartAt (ModelProd H E) p)
⊢ Continuous[_, instTopologicalSpaceModelProd H E] (TotalSpace.toProd H E).toFun
Module: Mathlib.Geometry.Manifold.MFDeriv.Atlas

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
H : Type u_3
inst✝³ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
inst✝ : IsManifold I 1 M
x₀ x : M
hx : x ∈ (chartAt H x₀).source
⊢ Trivialization.continuousLinearMapAt 𝕜 (trivializationAt E (TangentSpace I) x₀) x = mfderiv% ↑(extChartAt I x₀) x

Tactic:
have : MDiffAt (extChartAt I x₀) x := mdifferentiableAt_extChartAt hx

Goal state after:
𝕜 : Type u_1
inst✝⁶ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace 𝕜 E
H : Type u_3
inst✝³ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
inst✝ : IsManifold I 1 M
x₀ x : M
hx : x ∈ (chartAt H x₀).source
this : MDiffAt ↑(extChartAt I x₀) x
⊢ Trivialization.continuousLinearMapAt 𝕜 (trivializationAt E (TangentSpace I) x₀) x = mfderiv% ↑(extChartAt I x₀) x
Module: Mathlib.Geometry.Manifold.BumpFunction

Goal state before:
pp: E : Type uE
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
H : Type uH
inst✝³ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type uM
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
c : M
f : SmoothBumpFunction I c
inst✝ : FiniteDimensional ℝ E
s : Set M
hsc : IsClosed[inst✝²] s
hs : s ⊆ support ↑f
⊢ IsClosed[PseudoMetricSpace.toUniformSpace.toTopologicalSpace]
    (closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s)

Tactic:
refine ContinuousOn.preimage_isClosed_of_isClosed
    ((continuousOn_extChartAt_symm _).mono f.closedBall_subset) ?_ hsc

Goal state after:
E : Type uE
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
H : Type uH
inst✝³ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type uM
inst✝² : TopologicalSpace M
inst✝¹ : ChartedSpace H M
c : M
f : SmoothBumpFunction I c
inst✝ : FiniteDimensional ℝ E
s : Set M
hsc : IsClosed[inst✝²] s
hs : s ⊆ support ↑f
⊢ IsClosed[PseudoMetricSpace.toUniformSpace.toTopologicalSpace] (closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I)
Module: Mathlib.Topology.Compactness.Paracompact

Goal state before:
pp: ι : Type u
X : Type v
inst✝¹ : TopologicalSpace X
inst✝ : ParacompactSpace X
u : ι → Set X
uo : ∀ (a : ι), IsOpen[inst✝¹] (u a)
uc : ⋃ i, u i = univ
this : ∃ β t, (∀ (b : β), IsOpen[inst✝¹] (t b)) ∧ ⋃ b, t b = univ ∧ LocallyFinite t ∧ ∀ (b : β), ∃ a, t b ⊆ ↑a
⊢ ∃ v, (∀ (a : ι), IsOpen[inst✝¹] (v a)) ∧ ⋃ i, v i = univ ∧ LocallyFinite v ∧ ∀ (a : ι), v a ⊆ u a

Tactic:
simp only [exists_subtype_range_iff, iUnion_eq_univ_iff] at this

Goal state after:
ι : Type u
X : Type v
inst✝¹ : TopologicalSpace X
inst✝ : ParacompactSpace X
u : ι → Set X
uo : ∀ (a : ι), IsOpen[inst✝¹] (u a)
uc : ⋃ i, u i = univ
this :
  ∃ β t, (∀ (b : β), IsOpen[inst✝¹] (t b)) ∧ (∀ (x : X), ∃ i, x ∈ t i) ∧ LocallyFinite t ∧ ∀ (b : β), ∃ i, t b ⊆ u i
⊢ ∃ v, (∀ (a : ι), IsOpen[inst✝¹] (v a)) ∧ ⋃ i, v i = univ ∧ LocallyFinite v ∧ ∀ (a : ι), v a ⊆ u a
Module: Mathlib.Geometry.Manifold.BumpFunction

Goal state before:
pp: E : Type uE
inst✝⁷ : NormedAddCommGroup E
inst✝⁶ : NormedSpace ℝ E
H : Type uH
inst✝⁵ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type uM
inst✝⁴ : TopologicalSpace M
inst✝³ : ChartedSpace H M
c : M
f : SmoothBumpFunction I c
inst✝² : FiniteDimensional ℝ E
inst✝¹ : T2Space M
inst✝ : IsManifold I ∞ M
x : M
hx : x ∈ tsupport ↑f
⊢ ContMDiffAt I 𝓘(ℝ, ℝ) ∞ (↑f) x

Tactic:
have : x ∈ (chartAt H c).source := f.tsupport_subset_chartAt_source hx

Goal state after:
E : Type uE
inst✝⁷ : NormedAddCommGroup E
inst✝⁶ : NormedSpace ℝ E
H : Type uH
inst✝⁵ : TopologicalSpace H
I : ModelWithCorners ℝ E H
M : Type uM
inst✝⁴ : TopologicalSpace M
inst✝³ : ChartedSpace H M
c : M
f : SmoothBumpFunction I c
inst✝² : FiniteDimensional ℝ E
inst✝¹ : T2Space M
inst✝ : IsManifold I ∞ M
x : M
hx : x ∈ tsupport ↑f
this : x ∈ (chartAt H c).source
⊢ ContMDiffAt I 𝓘(ℝ, ℝ) ∞ (↑f) x
Module: Mathlib.Geometry.Manifold.VectorBundle.ContMDiffSection

Goal state before:
pp: case refine_1
𝕜 : Type u_1
inst✝¹³ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹² : NormedAddCommGroup E
inst✝¹¹ : NormedSpace 𝕜 E
H : Type u_3
inst✝¹⁰ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁹ : TopologicalSpace M
inst✝⁸ : ChartedSpace H M
F : Type u_5
inst✝⁷ : NormedAddCommGroup F
inst✝⁶ : NormedSpace 𝕜 F
n : ℕ∞ω
V : M → Type u_6
inst✝⁵ : TopologicalSpace (TotalSpace F V)
inst✝⁴ : (x : M) → TopologicalSpace (V x)
inst✝³ : FiberBundle F V
inst✝² : (x : M) → AddCommGroup (V x)
inst✝¹ : (x : M) → Module 𝕜 (V x)
inst✝ : VectorBundle 𝕜 F V
s t : (x : M) → V x
u : Set M
x₀ : M
e : Trivialization F TotalSpace.proj := trivializationAt F V x₀
hs : ContMDiffWithinAt I 𝓘(𝕜, F) n (fun x ↦ (↑e ⟨x, s x⟩).2) u x₀
ht : ContMDiffWithinAt I 𝓘(𝕜, F) n (fun x ↦ (↑e ⟨x, t x⟩).2) u x₀
⊢ (fun x ↦ (↑e ⟨x, (s + t) x⟩).2) =ᶠ[nhdsWithin x₀ u] (fun x ↦ (↑e ⟨x, s x⟩).2) + fun x ↦ (↑e ⟨x, t x⟩).2

pp: case refine_2
𝕜 : Type u_1
inst✝¹³ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹² : NormedAddCommGroup E
inst✝¹¹ : NormedSpace 𝕜 E
H : Type u_3
inst✝¹⁰ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁹ : TopologicalSpace M
inst✝⁸ : ChartedSpace H M
F : Type u_5
inst✝⁷ : NormedAddCommGroup F
inst✝⁶ : NormedSpace 𝕜 F
n : ℕ∞ω
V : M → Type u_6
inst✝⁵ : TopologicalSpace (TotalSpace F V)
inst✝⁴ : (x : M) → TopologicalSpace (V x)
inst✝³ : FiberBundle F V
inst✝² : (x : M) → AddCommGroup (V x)
inst✝¹ : (x : M) → Module 𝕜 (V x)
inst✝ : VectorBundle 𝕜 F V
s t : (x : M) → V x
u : Set M
x₀ : M
e : Trivialization F TotalSpace.proj := trivializationAt F V x₀
hs : ContMDiffWithinAt I 𝓘(𝕜, F) n (fun x ↦ (↑e ⟨x, s x⟩).2) u x₀
ht : ContMDiffWithinAt I 𝓘(𝕜, F) n (fun x ↦ (↑e ⟨x, t x⟩).2) u x₀
⊢ (↑e ⟨x₀, (s + t) x₀⟩).2 = ((fun x ↦ (↑e ⟨x, s x⟩).2) + fun x ↦ (↑e ⟨x, t x⟩).2) x₀

Tactic:
· apply eventually_of_mem (U := e.baseSet)
    · exact mem_nhdsWithin_of_mem_nhds <|
        (e.open_baseSet.mem_nhds <| mem_baseSet_trivializationAt F V x₀)
    · intro x hx
      apply (e.linear 𝕜 hx).1

Goal state after:
case refine_2
𝕜 : Type u_1
inst✝¹³ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝¹² : NormedAddCommGroup E
inst✝¹¹ : NormedSpace 𝕜 E
H : Type u_3
inst✝¹⁰ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁹ : TopologicalSpace M
inst✝⁸ : ChartedSpace H M
F : Type u_5
inst✝⁷ : NormedAddCommGroup F
inst✝⁶ : NormedSpace 𝕜 F
n : ℕ∞ω
V : M → Type u_6
inst✝⁵ : TopologicalSpace (TotalSpace F V)
inst✝⁴ : (x : M) → TopologicalSpace (V x)
inst✝³ : FiberBundle F V
inst✝² : (x : M) → AddCommGroup (V x)
inst✝¹ : (x : M) → Module 𝕜 (V x)
inst✝ : VectorBundle 𝕜 F V
s t : (x : M) → V x
u : Set M
x₀ : M
e : Trivialization F TotalSpace.proj := trivializationAt F V x₀
hs : ContMDiffWithinAt I 𝓘(𝕜, F) n (fun x ↦ (↑e ⟨x, s x⟩).2) u x₀
ht : ContMDiffWithinAt I 𝓘(𝕜, F) n (fun x ↦ (↑e ⟨x, t x⟩).2) u x₀
⊢ (↑e ⟨x₀, (s + t) x₀⟩).2 = ((fun x ↦ (↑e ⟨x, s x⟩).2) + fun x ↦ (↑e ⟨x, t x⟩).2) x₀
Module: Mathlib.Topology.Compactness.Paracompact

Goal state before:
pp: case refine_3
X : Type v
inst✝³ : TopologicalSpace X
inst✝² : WeaklyLocallyCompactSpace X
inst✝¹ : SigmaCompactSpace X
inst✝ : T2Space X
ι : X → Type u
p : (x : X) → ι x → Prop
B : (x : X) → ι x → Set X
s : Set X
hs : IsClosed[inst✝³] s
hB : ∀ x ∈ s, (𝓝 x).HasBasis (p x) (B x)
K' : CompactExhaustion X := CompactExhaustion.choice X
K : CompactExhaustion X := K'.shiftr.shiftr
Kdiff : ℕ → Set X := fun n ↦ K (n + 1) \ interior (K n)
hKcov : ∀ (x : X), x ∈ Kdiff (K'.find x + 1)
Kdiffc : ∀ (n : ℕ), IsCompact (Kdiff n ∩ s)
this : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), (K n)ᶜ ∈ 𝓝 ↑x
r : (n : ℕ) → (x : ↑(Kdiff (n + 1) ∩ s)) → ι ↑x
hrp : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), p (↑x) (r n x)
hr : ∀ (n : ℕ) (x : ↑(Kdiff (n + 1) ∩ s)), B (↑x) (r n x) ⊆ (K n)ᶜ
hxr : ∀ (n : ℕ) (x : X) (hx : x ∈ Kdiff (n + 1) ∩ s), B x (r n ⟨x, hx⟩) ∈ 𝓝 x
T : (n : ℕ) → Finset ↑(Kdiff (n + 1) ∩ s)
hT : ∀ (n : ℕ), Kdiff (n + 1) ∩ s ⊆ ⋃ x ∈ T n, B (↑x) (r n ⟨↑x, ⋯⟩)
T' : (n : ℕ) → Set ↑(Kdiff (n + 1) ∩ s) := fun n ↦ ↑(T n)
⊢ LocallyFinite fun a ↦ B ((fun a ↦ ↑↑a.snd) a) ((fun a ↦ r a.fst ↑a.snd) a)

Tactic:
· intro x
    refine
      ⟨interior (K (K'.find x + 3)),
        IsOpen.mem_nhds isOpen_interior (K.subset_interior_succ _ (hKcov x).1), ?_⟩
    have : (⋃ k ≤ K'.find x + 2, range (Sigma.mk k) : Set (Σ n, T' n)).Finite :=
      (finite_le_nat _).biUnion fun k _ ↦ finite_range _
    apply this.subset
    rintro ⟨k, c, hc⟩
    simp only [mem_iUnion, mem_ofPred_eq, Subtype.coe_mk]
    rintro ⟨x, hxB : x ∈ B c (r k c), hxK⟩
    refine ⟨k, ?_, ⟨c, hc⟩, rfl⟩
    have := (mem_compl_iff _ _).1 (hr k c hxB)
    contrapose! this with hnk
    exact K.subset hnk (interior_subset hxK)

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 : ∀ (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
x : α
n : ℕ
hn : eball x (3 * 2⁻¹ ^ n) ⊆ s (ind x)
⊢ ∃ n i, x ∈ D n i

Tactic:
by_contra! h

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
x : α
n : ℕ
hn : eball x (3 * 2⁻¹ ^ n) ⊆ s (ind x)
h : ∀ (n : ℕ) (i : ι), x ∉ D n i
⊢ False