mathlib-initiative/mathlib-tactics huggingface dataset:
Module: Mathlib.Geometry.Manifold.IsManifold.ExtChartAt

Goal state before:
pp: 𝕜 : Type u_1
E : Type u_2
M : Type u_3
H : Type u_4
E' : Type u_5
M' : Type u_6
H' : Type u_7
inst✝¹⁰ : NontriviallyNormedField 𝕜
inst✝⁹ : NormedAddCommGroup E
inst✝⁸ : NormedSpace 𝕜 E
inst✝⁷ : TopologicalSpace H
inst✝⁶ : TopologicalSpace M
I : ModelWithCorners 𝕜 E H
inst✝⁵ : NormedAddCommGroup E'
inst✝⁴ : NormedSpace 𝕜 E'
inst✝³ : TopologicalSpace H'
inst✝² : TopologicalSpace M'
I' : ModelWithCorners 𝕜 E' H'
inst✝¹ : ChartedSpace H M
inst✝ : ChartedSpace H' M'
x : M
f : M → M'
x' : E
hx' : x' ∈ (extChartAt I x).target ∩ f ∘ ↑(extChartAt I x).symm ⁻¹' (extChartAt I' (f x)).source
⊢ f (↑(chartAt H x).symm (↑I.symm x')) ∈ (chartAt H' (f x)).source

Tactic:
simpa using hx'.2

Goal state after:
Module: Mathlib.MeasureTheory.Function.Jacobian

Goal state before:
pp: E : Type u_1
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : FiniteDimensional ℝ E
s : Set E
f : E → E
f' : E → E →L[ℝ] E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : μ.IsAddHaarMeasure
hs : NullMeasurableSet s μ
hf' : ∀ x ∈ s, HasFDerivWithinAt f (f' x) s x
hf : InjOn f s
h'f : AEMeasurable f (μ.restrict s)
h''f : AEMeasurable f ((μ.restrict s).withDensity fun x ↦ ENNReal.ofReal |(f' x).det|)
t : Set E
ht : MeasurableSet t
h't : NullMeasurableSet (f ⁻¹' t) (μ.restrict s)
⊢ ∫⁻ (a : E) in f ⁻¹' t, ENNReal.ofReal |(f' a).det| ∂μ.restrict s = (μ.restrict (f '' s)) t

Tactic:
Measure.restrict_apply ht,

Goal state after:
E : Type u_1
inst✝⁵ : NormedAddCommGroup E
inst✝⁴ : NormedSpace ℝ E
inst✝³ : FiniteDimensional ℝ E
s : Set E
f : E → E
f' : E → E →L[ℝ] E
inst✝² : MeasurableSpace E
inst✝¹ : BorelSpace E
μ : Measure E
inst✝ : μ.IsAddHaarMeasure
hs : NullMeasurableSet s μ
hf' : ∀ x ∈ s, HasFDerivWithinAt f (f' x) s x
hf : InjOn f s
h'f : AEMeasurable f (μ.restrict s)
h''f : AEMeasurable f ((μ.restrict s).withDensity fun x ↦ ENNReal.ofReal |(f' x).det|)
t : Set E
ht : MeasurableSet t
h't : NullMeasurableSet (f ⁻¹' t) (μ.restrict s)
⊢ ∫⁻ (a : E) in f ⁻¹' t, ENNReal.ofReal |(f' a).det| ∂μ.restrict s = μ (t ∩ f '' s)
Module: Mathlib.Geometry.Manifold.ContMDiff.Basic

Goal state before:
pp: case right
𝕜 : Type u_1
inst✝⁵ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁴ : NormedAddCommGroup E
inst✝³ : NormedSpace 𝕜 E
H : Type u_3
inst✝² : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝¹ : TopologicalSpace M
e : M → H
h : IsOpenEmbedding e
n : ℕ∞ω
inst✝ : Nonempty M
this✝ : IsManifold I ω M
z✝ : H
hz✝ : M
z : E
hz :
  z ∈
    (extChartAt I z✝).target ∩
      ↑(extChartAt I z✝).symm ⁻¹'
        (range e ∩ ↑(IsOpenEmbedding.toOpenPartialHomeomorph e h).symm ⁻¹' (extChartAt I hz✝).source)
this : ↑I.symm z ∈ range e
⊢ z ∈ range ↑I

Tactic:
exact mem_of_subset_of_mem (extChartAt_target_subset_range _) hz.1

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

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'
f : M → M'
x : M
⊢ LiftPropAt (DifferentiableWithinAtProp I I') f x ↔
    ContinuousAt f x ∧ DifferentiableWithinAt 𝕜 (writtenInExtChartAt I I' x f) (range ↑I) (↑(extChartAt I x) x)

Tactic:
liftPropAt_iff

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
⊢ ContinuousAt f x ∧
      DifferentiableWithinAtProp I I' (↑(chartAt H' (f x)) ∘ f ∘ ↑(chartAt H x).symm) univ (↑(chartAt H x) x) ↔
    ContinuousAt f x ∧ DifferentiableWithinAt 𝕜 (writtenInExtChartAt I I' x f) (range ↑I) (↑(extChartAt I x) x)
Module: Mathlib.Geometry.Manifold.ContMDiff.Defs

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'
f : M → M'
s t : Set M
x : M
n : ℕ∞ω
y : M
h : s =ᶠ[𝓝[{y}ᶜ] x] t
⊢ ContMDiffWithinAt I I' n f s x ↔ ContMDiffWithinAt I I' n f t x

Tactic:
have : T1Space M := I.t1Space M
  rw [← contMDiffWithinAt_insert_self (s := s), ← contMDiffWithinAt_insert_self (s := t)]
  exact contMDiffWithinAt_congr_set (eventuallyEq_insert h)

Goal state after:
Module: Mathlib.Geometry.Manifold.ContMDiff.NormedSpace

Goal state before:
pp: 𝕜 : Type u_1
inst✝⁹ : NontriviallyNormedField 𝕜
E : Type u_2
inst✝⁸ : NormedAddCommGroup E
inst✝⁷ : NormedSpace 𝕜 E
H : Type u_3
inst✝⁶ : TopologicalSpace H
I : ModelWithCorners 𝕜 E H
M : Type u_4
inst✝⁵ : TopologicalSpace M
inst✝⁴ : ChartedSpace H M
F₁ : Type u_8
inst✝³ : NormedAddCommGroup F₁
inst✝² : NormedSpace 𝕜 F₁
F₂ : Type u_9
inst✝¹ : NormedAddCommGroup F₂
inst✝ : NormedSpace 𝕜 F₂
n : WithTop ℕ∞
g : M → F₁ →L[𝕜] F₂
f : M → F₁
s : Set M
x : M
hg : ContMDiffWithinAt I 𝓘(𝕜, F₁ →L[𝕜] F₂) n g s x
hf : ContMDiffWithinAt I 𝓘(𝕜, F₁) n f s x
⊢ ContDiffWithinAt 𝕜 n (fun x ↦ x.1 x.2) univ (g x, f x)

Tactic:
apply ContDiff.contDiffAt; exact contDiff_fst.clm_apply contDiff_snd

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

Goal state before:
pp: 𝕜 : Type u_1
B : Type u_2
F : Type u_3
inst✝⁷ : TopologicalSpace B
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAddCommGroup F
inst✝⁴ : NormedSpace 𝕜 F
EB : Type u_4
inst✝³ : NormedAddCommGroup EB
inst✝² : NormedSpace 𝕜 EB
HB : Type u_5
inst✝¹ : TopologicalSpace HB
inst✝ : ChartedSpace HB B
IB : ModelWithCorners 𝕜 EB HB
n : ℕ∞ω
e : OpenPartialHomeomorph (B × F) (B × F)
s : ↑e.source → Set (B × F)
hs : ∀ (x : ↑e.source), IsOpen[instTopologicalSpaceProd] (s x)
hsp : ∀ (x : ↑e.source), ↑x ∈ s x
φ : ↑e.source → B → F ≃L[𝕜] F
u : ↑e.source → Set B
hu : ∀ (x : ↑e.source), IsOpen[inst✝⁷] (u x)
hφ : ∀ (x : ↑e.source), ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x_1 ↦ ↑(φ x x_1)) (u x)
h2φ : ∀ (x : ↑e.source), ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x_1 ↦ ↑(φ x x_1).symm) (u x)
heφ : ∀ (x : ↑e.source), (e.restr (s x)).EqOnSource (FiberwiseLinear.openPartialHomeomorph (φ x) ⋯ ⋯ ⋯)
hesu : ∀ (p : ↑e.source), e.source ∩ s p = u p ×ˢ univ
⊢ ∃ U,
    e.source = U ×ˢ univ ∧
      ∀ x ∈ U,
        ∃ φ u,
          ∃ (hu : IsOpen[inst✝⁷] u) (_ : u ⊆ U) (_ : x ∈ u) (hφ : ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x ↦ ↑(φ x)) u)
            (h2φ : ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x ↦ ↑(φ x).symm) u),
            (e.restr (u ×ˢ univ)).EqOnSource (FiberwiseLinear.openPartialHomeomorph φ hu ⋯ ⋯)

Tactic:
have hu' : ∀ p : e.source, (p : B × F).fst ∈ u p := by
    intro p
    have : (p : B × F) ∈ e.source ∩ s p := ⟨p.prop, hsp p⟩
    simpa only [hesu, mem_prod, mem_univ, and_true] using this

Goal state after:
𝕜 : Type u_1
B : Type u_2
F : Type u_3
inst✝⁷ : TopologicalSpace B
inst✝⁶ : NontriviallyNormedField 𝕜
inst✝⁵ : NormedAddCommGroup F
inst✝⁴ : NormedSpace 𝕜 F
EB : Type u_4
inst✝³ : NormedAddCommGroup EB
inst✝² : NormedSpace 𝕜 EB
HB : Type u_5
inst✝¹ : TopologicalSpace HB
inst✝ : ChartedSpace HB B
IB : ModelWithCorners 𝕜 EB HB
n : ℕ∞ω
e : OpenPartialHomeomorph (B × F) (B × F)
s : ↑e.source → Set (B × F)
hs : ∀ (x : ↑e.source), IsOpen[instTopologicalSpaceProd] (s x)
hsp : ∀ (x : ↑e.source), ↑x ∈ s x
φ : ↑e.source → B → F ≃L[𝕜] F
u : ↑e.source → Set B
hu : ∀ (x : ↑e.source), IsOpen[inst✝⁷] (u x)
hφ : ∀ (x : ↑e.source), ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x_1 ↦ ↑(φ x x_1)) (u x)
h2φ : ∀ (x : ↑e.source), ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x_1 ↦ ↑(φ x x_1).symm) (u x)
heφ : ∀ (x : ↑e.source), (e.restr (s x)).EqOnSource (FiberwiseLinear.openPartialHomeomorph (φ x) ⋯ ⋯ ⋯)
hesu : ∀ (p : ↑e.source), e.source ∩ s p = u p ×ˢ univ
hu' : ∀ (p : ↑e.source), (↑p).1 ∈ u p
⊢ ∃ U,
    e.source = U ×ˢ univ ∧
      ∀ x ∈ U,
        ∃ φ u,
          ∃ (hu : IsOpen[inst✝⁷] u) (_ : u ⊆ U) (_ : x ∈ u) (hφ : ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x ↦ ↑(φ x)) u)
            (h2φ : ContMDiffOn IB 𝓘(𝕜, F →L[𝕜] F) n (fun x ↦ ↑(φ x).symm) u),
            (e.restr (u ×ˢ univ)).EqOnSource (FiberwiseLinear.openPartialHomeomorph φ hu ⋯ ⋯)
Module: Mathlib.Topology.FiberBundle.Constructions

Goal state before:
pp: B : Type u
F : Type v
E : B → Type w₁
B' : Type w₂
f✝ : B' → B
inst✝⁶ : TopologicalSpace B'
inst✝⁵ : TopologicalSpace (TotalSpace F E)
inst✝⁴ : TopologicalSpace F
inst✝³ : TopologicalSpace B
inst✝² : ∀ (_b : B), Nonempty (E _b)
K : Type U
inst✝¹ : FunLike K B' B
inst✝ : ContinuousMapClass K B' B
e : Trivialization F TotalSpace.proj
f : K
x : TotalSpace F (⇑f *ᵖ E)
h : Pullback.lift (⇑f) x ∈ e.source
⊢ TotalSpace.mk' F (x.proj, (↑e (Pullback.lift (⇑f) x)).2).1
      (e.symm (f (x.proj, (↑e (Pullback.lift (⇑f) x)).2).1) (x.proj, (↑e (Pullback.lift (⇑f) x)).2).2) =
    x

Tactic:
e.mem_source,

Goal state after:
B : Type u
F : Type v
E : B → Type w₁
B' : Type w₂
f✝ : B' → B
inst✝⁶ : TopologicalSpace B'
inst✝⁵ : TopologicalSpace (TotalSpace F E)
inst✝⁴ : TopologicalSpace F
inst✝³ : TopologicalSpace B
inst✝² : ∀ (_b : B), Nonempty (E _b)
K : Type U
inst✝¹ : FunLike K B' B
inst✝ : ContinuousMapClass K B' B
e : Trivialization F TotalSpace.proj
f : K
x : TotalSpace F (⇑f *ᵖ E)
h : (Pullback.lift (⇑f) x).proj ∈ e.baseSet
⊢ TotalSpace.mk' F (x.proj, (↑e (Pullback.lift (⇑f) x)).2).1
      (e.symm (f (x.proj, (↑e (Pullback.lift (⇑f) x)).2).1) (x.proj, (↑e (Pullback.lift (⇑f) x)).2).2) =
    x
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✝⁹ : NontriviallyNormedField R
inst✝⁸ : (x : B) → AddCommMonoid (E x)
inst✝⁷ : (x : B) → Module R (E x)
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace R F
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace (TotalSpace F E)
inst✝² : (x : B) → TopologicalSpace (E x)
inst✝¹ : FiberBundle F E
inst✝ : VectorBundle R F E
x : B
⊢ ContinuousAt (fun x ↦ { proj := x, snd := 0 }) x

Tactic:
FiberBundle.continuousAt_section

Goal state after:
R : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
inst✝⁹ : NontriviallyNormedField R
inst✝⁸ : (x : B) → AddCommMonoid (E x)
inst✝⁷ : (x : B) → Module R (E x)
inst✝⁶ : NormedAddCommGroup F
inst✝⁵ : NormedSpace R F
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace (TotalSpace F E)
inst✝² : (x : B) → TopologicalSpace (E x)
inst✝¹ : FiberBundle F E
inst✝ : VectorBundle R F E
x : B
⊢ ContinuousAt (fun x_1 ↦ (↑(trivializationAt F E x) { proj := x_1, snd := 0 }).2) x
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'
i j : ↑(atlas H M)
⊢ ContinuousOn (fun x ↦ fderivWithin 𝕜 (↑((↑j).extend I) ∘ ↑((↑i).extend I).symm) (range ↑I) (↑((↑i).extend I) x))
    ((↑i).source ∩ (↑j).source)

Tactic:
have : IsManifold I (0 + 1) M := by simpa

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'
i j : ↑(atlas H M)
this : IsManifold I (0 + 1) M
⊢ ContinuousOn (fun x ↦ fderivWithin 𝕜 (↑((↑j).extend I) ∘ ↑((↑i).extend I).symm) (range ↑I) (↑((↑i).extend I) x))
    ((↑i).source ∩ (↑j).source)
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'
⊢ ∀ (i j k : ↑(atlas H M)),
    ∀ x ∈ (↑i).source ∩ (↑j).source ∩ (↑k).source,
      ∀ (v : E),
        (fderivWithin 𝕜 (↑((↑k).extend I) ∘ ↑((↑j).extend I).symm) (range ↑I) (↑((↑j).extend I) x))
            ((fderivWithin 𝕜 (↑((↑j).extend I) ∘ ↑((↑i).extend I).symm) (range ↑I) (↑((↑i).extend I) x)) v) =
          (fderivWithin 𝕜 (↑((↑k).extend I) ∘ ↑((↑i).extend I).symm) (range ↑I) (↑((↑i).extend I) x)) v

Tactic:
have : IsManifold I (0 + 1) M := by simpa

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'
this : IsManifold I (0 + 1) M
⊢ ∀ (i j k : ↑(atlas H M)),
    ∀ x ∈ (↑i).source ∩ (↑j).source ∩ (↑k).source,
      ∀ (v : E),
        (fderivWithin 𝕜 (↑((↑k).extend I) ∘ ↑((↑j).extend I).symm) (range ↑I) (↑((↑j).extend I) x))
            ((fderivWithin 𝕜 (↑((↑j).extend I) ∘ ↑((↑i).extend I).symm) (range ↑I) (↑((↑i).extend I) x)) v) =
          (fderivWithin 𝕜 (↑((↑k).extend I) ∘ ↑((↑i).extend I).symm) (range ↑I) (↑((↑i).extend I) x)) v
Module: Mathlib.Geometry.Manifold.MFDeriv.Basic

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''
f : M → M'
x : M
g : M' → M''
hg : MDiffAt g (f x)
hf : MDiffAt f x
v : TangentSpace I x
⊢ (mfderiv% (g ∘ f) x) v = (mfderiv% g (f x)) ((mfderiv% f x) v)

Tactic:
by
  rw [mfderiv_comp _ hg hf]
  rfl

Goal state after:
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
x y : M
hy : y ∈ (extChartAt I x).source
⊢ mfderiv% ↑(extChartAt I x) y ∘SL mfderiv[range ↑I] ↑(extChartAt I x).symm (↑(extChartAt I x) y) =
    ContinuousLinearMap.id 𝕜 (TangentSpace 𝓘(𝕜, E) (↑(extChartAt I x) y))

Tactic:
have : y = (extChartAt I x).symm (extChartAt I x y) := ((extChartAt I x).left_inv hy).symm
  convert! mfderiv_extChartAt_comp_mfderivWithin_extChartAt_symm ((extChartAt I x).map_source hy)

Goal state after:
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
E : B → Type u_6
inst✝¹⁰ : NontriviallyNormedField 𝕜
EB : Type u_7
inst✝⁹ : NormedAddCommGroup EB
inst✝⁸ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁷ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
inst✝⁶ : TopologicalSpace B
inst✝⁵ : ChartedSpace HB B
inst✝⁴ : (x : B) → AddCommMonoid (E x)
inst✝³ : (x : B) → Module 𝕜 (E x)
inst✝² : NormedAddCommGroup F
inst✝¹ : NormedSpace 𝕜 F
inst✝ : (x : B) → TopologicalSpace (E x)
a : VectorPrebundle 𝕜 F E
ha : IsContMDiff IB a n
e e' : Pretrivialization F TotalSpace.proj
he : e ∈ a.pretrivializationAtlas
he' : e' ∈ a.pretrivializationAtlas
b : B
hb : b ∈ e.baseSet ∩ e'.baseSet
v : F
⊢ (b, (contMDiffCoordChange n IB a he he' b) v) = ↑e' { proj := b, snd := e.symm b v }

Tactic:
ext
  · rw [e.mk_symm hb.1 v, e'.coe_fst', e.proj_symm_apply' hb.1]
    rw [e.proj_symm_apply' hb.1]; exact hb.2
  · exact a.contMDiffCoordChange_apply he he' hb v

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
M' : Type u_21
inst✝¹ : TopologicalSpace M'
inst✝ : ChartedSpace H M'
p : M ⊕ M'
q' : M'
⊢ HasMFDerivAt% Sum.inr q' (ContinuousLinearMap.id 𝕜 (TangentSpace I p))

Tactic:
simpa [HasMFDerivAt, hasMFDerivWithinAt_univ] using! hasMFDerivWithinAt_inr (t := Set.univ)

Goal state after:
Module: Mathlib.Topology.ShrinkingLemma

Goal state before:
pp: ι : Type u_1
X : Type u_2
inst✝ : TopologicalSpace X
u : ι → Set X
s : Set X
p : Set X → Prop
v : PartialRefinement u s p
i : ι
⊢ v.toFun i ⊆ u i

Tactic:
classical
  exact if h : i ∈ v.carrier then subset_closure.trans (v.closure_subset h) else (v.apply_eq h).le

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
⊢ ∃ β t,
    (∀ (b : β), IsOpen[PseudoEMetricSpace.toUniformSpace.toTopologicalSpace] (t b)) ∧
      ⋃ b, t b = univ ∧ LocallyFinite t ∧ ∀ (b : β), ∃ a, t b ⊆ s a

Tactic:
let ind (x : α) : ι := wellFounded_lt.min { i : ι | x ∈ s i } (hcov x)

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} ⋯
⊢ ∃ 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.Geometry.Manifold.VectorBundle.ContMDiffSection

Goal state before:
pp: case refine_1.h
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 := ⋯
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
⊢ ∀ x ∈ e.baseSet, (fun x ↦ (↑e ⟨x, (s + t) x⟩).2) x = ((fun x ↦ (↑e ⟨x, s x⟩).2) + fun x ↦ (↑e ⟨x, t x⟩).2) x

Tactic:
· intro x hx
      apply (e.linear 𝕜 hx).1

Goal state after:
Module: Mathlib.Topology.ShrinkingLemma

Goal state before:
pp: case h
ι : Type u_1
X : Type u_2
inst✝¹ : TopologicalSpace X
u : ι → Set X
s : Set X
inst✝ : NormalSpace X
v : PartialRefinement u s ⊤
hs : IsClosed s
i : ι
hi : i ∉ v.carrier
I : s ∩ ⋂ j, ⋂ (_ : j ≠ i), (v.toFun j)ᶜ ⊆ v.toFun i
C : IsClosed (s ∩ ⋂ j, ⋂ (_ : j ≠ i), (v.toFun j)ᶜ)
vi : Set X
ovi : IsOpen vi
hvi : s ∩ ⋂ j, ⋂ (_ : j ≠ i), (v.toFun j)ᶜ ⊆ vi
cvi : closure vi ⊆ v.toFun i
x : X
hx : x ∈ s
j : ι
hji : j ≠ i
hj : x ∈ v.toFun j
⊢ x ∈ update v.toFun i vi j

Tactic:
update_of_ne hji

Goal state after:
case h
ι : Type u_1
X : Type u_2
inst✝¹ : TopologicalSpace X
u : ι → Set X
s : Set X
inst✝ : NormalSpace X
v : PartialRefinement u s ⊤
hs : IsClosed s
i : ι
hi : i ∉ v.carrier
I : s ∩ ⋂ j, ⋂ (_ : j ≠ i), (v.toFun j)ᶜ ⊆ v.toFun i
C : IsClosed (s ∩ ⋂ j, ⋂ (_ : j ≠ i), (v.toFun j)ᶜ)
vi : Set X
ovi : IsOpen vi
hvi : s ∩ ⋂ j, ⋂ (_ : j ≠ i), (v.toFun j)ᶜ ⊆ vi
cvi : closure vi ⊆ v.toFun i
x : X
hx : x ∈ s
j : ι
hji : j ≠ i
hj : x ∈ v.toFun j
⊢ x ∈ v.toFun j
Module: Mathlib.Geometry.Manifold.VectorBundle.ContMDiffSection

Goal state before:
pp: 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
x₀ : M
hs : ContMDiffAt I (I.prod 𝓘(𝕜, F)) n (fun x ↦ ⟨x, s x⟩) x₀
ht : ContMDiffAt I (I.prod 𝓘(𝕜, F)) n (fun x ↦ ⟨x, t x⟩) x₀
⊢ ContMDiffAt I (I.prod 𝓘(𝕜, F)) n (fun x ↦ ⟨x, (s + -t) x⟩) x₀

Tactic:
apply hs.add_section ht.neg_section

Goal state after:
Module: Mathlib.Topology.ShrinkingLemma

Goal state before:
pp: case h
ι : Type u_1
X : Type u_2
inst✝² : TopologicalSpace X
u : ι → Set X
s : Set X
inst✝¹ : T2Space X
inst✝ : LocallyCompactSpace X
v : PartialRefinement u s fun w ↦ IsCompact (closure w)
hs : IsCompact s
i : ι
hi : i ∉ v.carrier
si : Set X := ⋯
hsi : si = s ∩ ⋂ i_1, ⋂ (_ : ¬i_1 = i), (v.toFun i_1)ᶜ
hsic : IsCompact si
this : si ⊆ v.toFun i
vi : Set X
hvi : IsOpen vi ∧ si ⊆ vi ∧ closure vi ⊆ v.toFun i ∧ IsCompact (closure vi)
x : X
hx : x ∈ s
j : ι
hji : j ≠ i
hj : x ∈ v.toFun j
⊢ x ∈ update v.toFun i vi j

Tactic:
update_of_ne hji

Goal state after:
case h
ι : Type u_1
X : Type u_2
inst✝² : TopologicalSpace X
u : ι → Set X
s : Set X
inst✝¹ : T2Space X
inst✝ : LocallyCompactSpace X
v : PartialRefinement u s fun w ↦ IsCompact (closure w)
hs : IsCompact s
i : ι
hi : i ∉ v.carrier
si : Set X := s ∩ (⋃ j, ⋃ (_ : j ≠ i), v.toFun j)ᶜ
hsi : si = s ∩ ⋂ i_1, ⋂ (_ : ¬i_1 = i), (v.toFun i_1)ᶜ
hsic : IsCompact si
this : si ⊆ v.toFun i
vi : Set X
hvi : IsOpen vi ∧ si ⊆ vi ∧ closure vi ⊆ v.toFun i ∧ IsCompact (closure vi)
x : X
hx : x ∈ s
j : ι
hji : j ≠ i
hj : x ∈ v.toFun j
⊢ x ∈ v.toFun j