l3lab/ntp-mathlib huggingface dataset:
/-- Characterization of C^n functions into a smooth vector bundle. -/
theorem contMDiffWithinAt_totalSpace (f : M → TotalSpace F E) {s : Set M} {x₀ : M} :
    ContMDiffWithinAt IM (IB.prod 𝓘(𝕜, F)) n f s x₀ ↔
      ContMDiffWithinAt IM IB n (fun x => (f x).proj) s x₀ ∧
      ContMDiffWithinAt IM 𝓘(𝕜, F) n (fun x ↦ (trivializationAt F E (f x₀).proj (f x)).2) s x₀ := by
  simp (config := { singlePass := true }) only [contMDiffWithinAt_iff_target]
  rw [and_and_and_comm, ← FiberBundle.continuousWithinAt_totalSpace, and_congr_right_iff]
  intro hf
  simp_rw [modelWithCornersSelf_prod, FiberBundle.extChartAt, Function.comp,
    PartialEquiv.trans_apply, PartialEquiv.prod_coe, PartialEquiv.refl_coe, extChartAt_self_apply,
    modelWithCornersSelf_coe, id_def]
  refine (contMDiffWithinAt_prod_iff _).trans (and_congr ?_ Iff.rfl)
  have h1 : (fun x => (f x).proj) ⁻¹' (trivializationAt F E (f x₀).proj).baseSet ∈ 𝓝[s] x₀ :=
    ((FiberBundle.continuous_proj F E).continuousWithinAt.comp hf (mapsTo_image f s))
      ((Trivialization.open_baseSet _).mem_nhds (mem_baseSet_trivializationAt F E _))
  refine EventuallyEq.contMDiffWithinAt_iff (eventually_of_mem h1 fun x hx => ?_) ?_
  · simp_rw [Function.comp, PartialHomeomorph.coe_coe, Trivialization.coe_coe]
    rw [Trivialization.coe_fst']
    

Proof state:
case refine_1.ex
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
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
h1 : (fun x => (f x).proj) ⁻¹' (trivializationAt F E (f x₀).proj).baseSet ∈ 𝓝[s] x₀
x : M
hx : x ∈ (fun x => (f x).proj) ⁻¹' (trivializationAt F E (f x₀).proj).baseSet
⊢ (f x).proj ∈ (trivializationAt F E (f x₀).proj).baseSet

Next tactic:
exact hx
/-- Characterization of C^n functions into a smooth vector bundle. -/
theorem contMDiffWithinAt_totalSpace (f : M → TotalSpace F E) {s : Set M} {x₀ : M} :
    ContMDiffWithinAt IM (IB.prod 𝓘(𝕜, F)) n f s x₀ ↔
      ContMDiffWithinAt IM IB n (fun x => (f x).proj) s x₀ ∧
      ContMDiffWithinAt IM 𝓘(𝕜, F) n (fun x ↦ (trivializationAt F E (f x₀).proj (f x)).2) s x₀ := by
  simp (config := { singlePass := true }) only [contMDiffWithinAt_iff_target]
  rw [and_and_and_comm, ← FiberBundle.continuousWithinAt_totalSpace, and_congr_right_iff]
  intro hf
  simp_rw [modelWithCornersSelf_prod, FiberBundle.extChartAt, Function.comp,
    PartialEquiv.trans_apply, PartialEquiv.prod_coe, PartialEquiv.refl_coe, extChartAt_self_apply,
    modelWithCornersSelf_coe, id_def]
  refine (contMDiffWithinAt_prod_iff _).trans (and_congr ?_ Iff.rfl)
  have h1 : (fun x => (f x).proj) ⁻¹' (trivializationAt F E (f x₀).proj).baseSet ∈ 𝓝[s] x₀ :=
    ((FiberBundle.continuous_proj F E).continuousWithinAt.comp hf (mapsTo_image f s))
      ((Trivialization.open_baseSet _).mem_nhds (mem_baseSet_trivializationAt F E _))
  refine EventuallyEq.contMDiffWithinAt_iff (eventually_of_mem h1 fun x hx => ?_) ?_
  · simp_rw [Function.comp, PartialHomeomorph.coe_coe, Trivialization.coe_coe]
    rw [Trivialization.coe_fst']
    exact hx
  · 

Proof state:
case refine_2
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
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
h1 : (fun x => (f x).proj) ⁻¹' (trivializationAt F E (f x₀).proj).baseSet ∈ 𝓝[s] x₀
⊢ (Prod.fst ∘ fun x =>
        (↑(extChartAt IB (f x₀).proj) (↑(trivializationAt F E (f x₀).proj).toPartialHomeomorph.toPartialEquiv (f x)).1,
          (↑(trivializationAt F E (f x₀).proj).toPartialHomeomorph.toPartialEquiv (f x)).2))
      x₀ =
    ↑(extChartAt IB (f x₀).proj) (f x₀).proj

Next tactic:
simp only [mfld_simps]
/-- Characterization of C^n functions into a smooth vector bundle. -/
theorem contMDiffAt_totalSpace (f : M → TotalSpace F E) (x₀ : M) :
    ContMDiffAt IM (IB.prod 𝓘(𝕜, F)) n f x₀ ↔
      ContMDiffAt IM IB n (fun x => (f x).proj) x₀ ∧
        ContMDiffAt IM 𝓘(𝕜, F) n (fun x => (trivializationAt F E (f x₀).proj (f x)).2) x₀ := by
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
f : M → TotalSpace F E
x₀ : M
⊢ ContMDiffAt IM (ModelWithCorners.prod IB 𝓘(𝕜, F)) n f x₀ ↔
    ContMDiffAt IM IB n (fun x => (f x).proj) x₀ ∧
      ContMDiffAt IM 𝓘(𝕜, F) n (fun x => (↑(trivializationAt F E (f x₀).proj) (f x)).2) x₀

Next tactic:
simp_rw [← contMDiffWithinAt_univ]
/-- Characterization of C^n functions into a smooth vector bundle. -/
theorem contMDiffAt_totalSpace (f : M → TotalSpace F E) (x₀ : M) :
    ContMDiffAt IM (IB.prod 𝓘(𝕜, F)) n f x₀ ↔
      ContMDiffAt IM IB n (fun x => (f x).proj) x₀ ∧
        ContMDiffAt IM 𝓘(𝕜, F) n (fun x => (trivializationAt F E (f x₀).proj (f x)).2) x₀ := by
  simp_rw [← contMDiffWithinAt_univ]; 

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
f : M → TotalSpace F E
x₀ : M
⊢ ContMDiffWithinAt IM (ModelWithCorners.prod IB 𝓘(𝕜, F)) n f univ x₀ ↔
    ContMDiffWithinAt IM IB n (fun x => (f x).proj) univ x₀ ∧
      ContMDiffWithinAt IM 𝓘(𝕜, F) n (fun x => (↑(trivializationAt F E (f x₀).proj) (f x)).2) univ x₀

Next tactic:
exact contMDiffWithinAt_totalSpace f
/-- Characterization of C^n sections of a smooth vector bundle. -/
theorem contMDiffAt_section (s : ∀ x, E x) (x₀ : B) :
    ContMDiffAt IB (IB.prod 𝓘(𝕜, F)) n (fun x => TotalSpace.mk' F x (s x)) x₀ ↔
      ContMDiffAt IB 𝓘(𝕜, F) n (fun x ↦ (trivializationAt F E x₀ ⟨x, s x⟩).2) x₀ := by
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
s : (x : B) → E x
x₀ : B
⊢ ContMDiffAt IB (ModelWithCorners.prod IB 𝓘(𝕜, F)) n (fun x => TotalSpace.mk' F x (s x)) x₀ ↔
    ContMDiffAt IB 𝓘(𝕜, F) n (fun x => (↑(trivializationAt F E x₀) { proj := x, snd := s x }).2) x₀

Next tactic:
simp_rw [contMDiffAt_totalSpace, and_iff_right_iff_imp]
/-- Characterization of C^n sections of a smooth vector bundle. -/
theorem contMDiffAt_section (s : ∀ x, E x) (x₀ : B) :
    ContMDiffAt IB (IB.prod 𝓘(𝕜, F)) n (fun x => TotalSpace.mk' F x (s x)) x₀ ↔
      ContMDiffAt IB 𝓘(𝕜, F) n (fun x ↦ (trivializationAt F E x₀ ⟨x, s x⟩).2) x₀ := by
  simp_rw [contMDiffAt_totalSpace, and_iff_right_iff_imp]; 

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
s : (x : B) → E x
x₀ : B
⊢ ContMDiffAt IB 𝓘(𝕜, F) n (fun x => (↑(trivializationAt F E x₀) (TotalSpace.mk' F x (s x))).2) x₀ →
    ContMDiffAt IB IB n (fun x => x) x₀

Next tactic:
intro
/-- Characterization of C^n sections of a smooth vector bundle. -/
theorem contMDiffAt_section (s : ∀ x, E x) (x₀ : B) :
    ContMDiffAt IB (IB.prod 𝓘(𝕜, F)) n (fun x => TotalSpace.mk' F x (s x)) x₀ ↔
      ContMDiffAt IB 𝓘(𝕜, F) n (fun x ↦ (trivializationAt F E x₀ ⟨x, s x⟩).2) x₀ := by
  simp_rw [contMDiffAt_totalSpace, and_iff_right_iff_imp]; intro; 

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
s : (x : B) → E x
x₀ : B
a✝ : ContMDiffAt IB 𝓘(𝕜, F) n (fun x => (↑(trivializationAt F E x₀) (TotalSpace.mk' F x (s x))).2) x₀
⊢ ContMDiffAt IB IB n (fun x => x) x₀

Next tactic:
exact contMDiffAt_id
theorem contMDiff_proj : ContMDiff (IB.prod 𝓘(𝕜, F)) IB n (π F E) := fun x ↦ by
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
x : TotalSpace F E
⊢ ContMDiffAt (ModelWithCorners.prod IB 𝓘(𝕜, F)) IB n TotalSpace.proj x

Next tactic:
have : ContMDiffAt (IB.prod 𝓘(𝕜, F)) (IB.prod 𝓘(𝕜, F)) n id x := contMDiffAt_id
theorem contMDiff_proj : ContMDiff (IB.prod 𝓘(𝕜, F)) IB n (π F E) := fun x ↦ by
  have : ContMDiffAt (IB.prod 𝓘(𝕜, F)) (IB.prod 𝓘(𝕜, F)) n id x := contMDiffAt_id
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
x : TotalSpace F E
this : ContMDiffAt (ModelWithCorners.prod IB 𝓘(𝕜, F)) (ModelWithCorners.prod IB 𝓘(𝕜, F)) n id x
⊢ ContMDiffAt (ModelWithCorners.prod IB 𝓘(𝕜, F)) IB n TotalSpace.proj x

Next tactic:
rw [contMDiffAt_totalSpace] at this
theorem contMDiff_proj : ContMDiff (IB.prod 𝓘(𝕜, F)) IB n (π F E) := fun x ↦ by
  have : ContMDiffAt (IB.prod 𝓘(𝕜, F)) (IB.prod 𝓘(𝕜, F)) n id x := contMDiffAt_id
  rw [contMDiffAt_totalSpace] at this
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁶ : NontriviallyNormedField 𝕜
inst✝¹⁵ : NormedAddCommGroup F
inst✝¹⁴ : NormedSpace 𝕜 F
inst✝¹³ : TopologicalSpace (TotalSpace F E)
inst✝¹² : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹¹ : NormedAddCommGroup EB
inst✝¹⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝⁸ : (x : B) → Zero (E' x)
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
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝² : TopologicalSpace B
inst✝¹ : ChartedSpace HB B
inst✝ : FiberBundle F E
x : TotalSpace F E
this :
  ContMDiffAt (ModelWithCorners.prod IB 𝓘(𝕜, F)) IB n (fun x => (id x).proj) x ∧
    ContMDiffAt (ModelWithCorners.prod IB 𝓘(𝕜, F)) 𝓘(𝕜, F) n
      (fun x_1 => (↑(trivializationAt F E (id x).proj) (id x_1)).2) x
⊢ ContMDiffAt (ModelWithCorners.prod IB 𝓘(𝕜, F)) IB n TotalSpace.proj x

Next tactic:
exact this.1
theorem smooth_zeroSection : Smooth IB (IB.prod 𝓘(𝕜, F)) (zeroSection F E) := fun x ↦ by
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁹ : NontriviallyNormedField 𝕜
inst✝¹⁸ : NormedAddCommGroup F
inst✝¹⁷ : NormedSpace 𝕜 F
inst✝¹⁶ : TopologicalSpace (TotalSpace F E)
inst✝¹⁵ : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹⁴ : NormedAddCommGroup EB
inst✝¹³ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝¹² : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝¹¹ : (x : B) → Zero (E' x)
EM : Type u_10
inst✝¹⁰ : NormedAddCommGroup EM
inst✝⁹ : NormedSpace 𝕜 EM
HM : Type u_11
inst✝⁸ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝⁷ : TopologicalSpace M
inst✝⁶ : ChartedSpace HM M
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝⁵ : TopologicalSpace B
inst✝⁴ : ChartedSpace HB B
inst✝³ : FiberBundle F E
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module 𝕜 (E x)
inst✝ : VectorBundle 𝕜 F E
x : B
⊢ ContMDiffAt IB (ModelWithCorners.prod IB 𝓘(𝕜, F)) ⊤ (zeroSection F E) x

Next tactic:
unfold zeroSection
theorem smooth_zeroSection : Smooth IB (IB.prod 𝓘(𝕜, F)) (zeroSection F E) := fun x ↦ by
  unfold zeroSection
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁹ : NontriviallyNormedField 𝕜
inst✝¹⁸ : NormedAddCommGroup F
inst✝¹⁷ : NormedSpace 𝕜 F
inst✝¹⁶ : TopologicalSpace (TotalSpace F E)
inst✝¹⁵ : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹⁴ : NormedAddCommGroup EB
inst✝¹³ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝¹² : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝¹¹ : (x : B) → Zero (E' x)
EM : Type u_10
inst✝¹⁰ : NormedAddCommGroup EM
inst✝⁹ : NormedSpace 𝕜 EM
HM : Type u_11
inst✝⁸ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝⁷ : TopologicalSpace M
inst✝⁶ : ChartedSpace HM M
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝⁵ : TopologicalSpace B
inst✝⁴ : ChartedSpace HB B
inst✝³ : FiberBundle F E
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module 𝕜 (E x)
inst✝ : VectorBundle 𝕜 F E
x : B
⊢ ContMDiffAt IB (ModelWithCorners.prod IB 𝓘(𝕜, F)) ⊤ (fun x => { proj := x, snd := 0 }) x

Next tactic:
rw [Bundle.contMDiffAt_section]
theorem smooth_zeroSection : Smooth IB (IB.prod 𝓘(𝕜, F)) (zeroSection F E) := fun x ↦ by
  unfold zeroSection
  rw [Bundle.contMDiffAt_section]
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁹ : NontriviallyNormedField 𝕜
inst✝¹⁸ : NormedAddCommGroup F
inst✝¹⁷ : NormedSpace 𝕜 F
inst✝¹⁶ : TopologicalSpace (TotalSpace F E)
inst✝¹⁵ : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹⁴ : NormedAddCommGroup EB
inst✝¹³ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝¹² : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝¹¹ : (x : B) → Zero (E' x)
EM : Type u_10
inst✝¹⁰ : NormedAddCommGroup EM
inst✝⁹ : NormedSpace 𝕜 EM
HM : Type u_11
inst✝⁸ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝⁷ : TopologicalSpace M
inst✝⁶ : ChartedSpace HM M
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝⁵ : TopologicalSpace B
inst✝⁴ : ChartedSpace HB B
inst✝³ : FiberBundle F E
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module 𝕜 (E x)
inst✝ : VectorBundle 𝕜 F E
x : B
⊢ ContMDiffAt IB 𝓘(𝕜, F) ⊤ (fun x_1 => (↑(trivializationAt F E x) { proj := x_1, snd := 0 }).2) x

Next tactic:
apply (contMDiffAt_const (c := 0)).congr_of_eventuallyEq
theorem smooth_zeroSection : Smooth IB (IB.prod 𝓘(𝕜, F)) (zeroSection F E) := fun x ↦ by
  unfold zeroSection
  rw [Bundle.contMDiffAt_section]
  apply (contMDiffAt_const (c := 0)).congr_of_eventuallyEq
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝¹⁹ : NontriviallyNormedField 𝕜
inst✝¹⁸ : NormedAddCommGroup F
inst✝¹⁷ : NormedSpace 𝕜 F
inst✝¹⁶ : TopologicalSpace (TotalSpace F E)
inst✝¹⁵ : (x : B) → TopologicalSpace (E x)
EB : Type u_7
inst✝¹⁴ : NormedAddCommGroup EB
inst✝¹³ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝¹² : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
E' : B → Type u_9
inst✝¹¹ : (x : B) → Zero (E' x)
EM : Type u_10
inst✝¹⁰ : NormedAddCommGroup EM
inst✝⁹ : NormedSpace 𝕜 EM
HM : Type u_11
inst✝⁸ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝⁷ : TopologicalSpace M
inst✝⁶ : ChartedSpace HM M
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝⁵ : TopologicalSpace B
inst✝⁴ : ChartedSpace HB B
inst✝³ : FiberBundle F E
inst✝² : (x : B) → AddCommMonoid (E x)
inst✝¹ : (x : B) → Module 𝕜 (E x)
inst✝ : VectorBundle 𝕜 F E
x : B
⊢ (fun x_1 => (↑(trivializationAt F E x) { proj := x_1, snd := 0 }).2) =ᶠ[𝓝 x] fun x => 0

Next tactic:
filter_upwards [(trivializationAt F E x).open_baseSet.mem_nhds
    (mem_baseSet_trivializationAt F E x)] with y hy
    using congr_arg Prod.snd <| (trivializationAt F E x).zeroSection 𝕜 hy
theorem smoothOn_symm_coordChangeL :
    SmoothOn IB 𝓘(𝕜, F →L[𝕜] F) (fun b : B => ((e.coordChangeL 𝕜 e' b).symm : F →L[𝕜] F))
      (e.baseSet ∩ e'.baseSet) := by
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝²² : NontriviallyNormedField 𝕜
EB : Type u_7
inst✝²¹ : NormedAddCommGroup EB
inst✝²⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝¹⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
inst✝¹⁸ : TopologicalSpace B
inst✝¹⁷ : ChartedSpace HB B
inst✝¹⁶ : SmoothManifoldWithCorners IB B
EM : Type u_9
inst✝¹⁵ : NormedAddCommGroup EM
inst✝¹⁴ : NormedSpace 𝕜 EM
HM : Type u_10
inst✝¹³ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝¹² : TopologicalSpace M
inst✝¹¹ : ChartedSpace HM M
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝¹⁰ : (x : B) → AddCommMonoid (E x)
inst✝⁹ : (x : B) → Module 𝕜 (E x)
inst✝⁸ : NormedAddCommGroup F
inst✝⁷ : NormedSpace 𝕜 F
inst✝⁶ : TopologicalSpace (TotalSpace F E)
inst✝⁵ : (x : B) → TopologicalSpace (E x)
inst✝⁴ : FiberBundle F E
inst✝³ : VectorBundle 𝕜 F E
inst✝² : SmoothVectorBundle F E IB
e e' : Trivialization F TotalSpace.proj
inst✝¹ : MemTrivializationAtlas e
inst✝ : MemTrivializationAtlas e'
⊢ SmoothOn IB 𝓘(𝕜, F →L[𝕜] F) (fun b => ↑(ContinuousLinearEquiv.symm (Trivialization.coordChangeL 𝕜 e e' b)))
    (e.baseSet ∩ e'.baseSet)

Next tactic:
rw [inter_comm]
theorem smoothOn_symm_coordChangeL :
    SmoothOn IB 𝓘(𝕜, F →L[𝕜] F) (fun b : B => ((e.coordChangeL 𝕜 e' b).symm : F →L[𝕜] F))
      (e.baseSet ∩ e'.baseSet) := by
  rw [inter_comm]
  

Proof state:
𝕜 : Type u_1
B : Type u_2
B' : Type u_3
F : Type u_4
M : Type u_5
E : B → Type u_6
inst✝²² : NontriviallyNormedField 𝕜
EB : Type u_7
inst✝²¹ : NormedAddCommGroup EB
inst✝²⁰ : NormedSpace 𝕜 EB
HB : Type u_8
inst✝¹⁹ : TopologicalSpace HB
IB : ModelWithCorners 𝕜 EB HB
inst✝¹⁸ : TopologicalSpace B
inst✝¹⁷ : ChartedSpace HB B
inst✝¹⁶ : SmoothManifoldWithCorners IB B
EM : Type u_9
inst✝¹⁵ : NormedAddCommGroup EM
inst✝¹⁴ : NormedSpace 𝕜 EM
HM : Type u_10
inst✝¹³ : TopologicalSpace HM
IM : ModelWithCorners 𝕜 EM HM
inst✝¹² : TopologicalSpace M
inst✝¹¹ : ChartedSpace HM M
Is : SmoothManifoldWithCorners IM M
n : ℕ∞
inst✝¹⁰ : (x : B) → AddCommMonoid (E x)
inst✝⁹ : (x : B) → Module 𝕜 (E x)
inst✝⁸ : NormedAddCommGroup F
inst✝⁷ : NormedSpace 𝕜 F
inst✝⁶ : TopologicalSpace (TotalSpace F E)
inst✝⁵ : (x : B) → TopologicalSpace (E x)
inst✝⁴ : FiberBundle F E
inst✝³ : VectorBundle 𝕜 F E
inst✝² : SmoothVectorBundle F E IB
e e' : Trivialization F TotalSpace.proj
inst✝¹ : MemTrivializationAtlas e
inst✝ : MemTrivializationAtlas e'
⊢ SmoothOn IB 𝓘(𝕜, F →L[𝕜] F) (fun b => ↑(ContinuousLinearEquiv.symm (Trivialization.coordChangeL 𝕜 e e' b)))
    (e'.baseSet ∩ e.baseSet)

Next tactic:
refine (SmoothVectorBundle.smoothOn_coordChangeL e' e).congr fun b hb ↦ ?_