Theorem: FiberBundle.extChartAt_target
File: Mathlib/Geometry/Manifold/VectorBundle/Basic.lean

Proof steps:
state_before: 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
⊢ (extChartAt (IB.prod 𝓘(𝕜, F)) x).target =
    ((extChartAt IB x.proj).target ∩ ↑(extChartAt IB x.proj).symm ⁻¹' (trivializationAt F E x.proj).baseSet) ×ˢ univ
state_after: 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
⊢ ((extChartAt IB x.proj).prod (PartialEquiv.refl F)).target ∩
      ↑((extChartAt IB x.proj).prod (PartialEquiv.refl F)).symm ⁻¹' (trivializationAt F E x.proj).baseSet ×ˢ univ =
    (extChartAt IB x.proj).target ×ˢ univ ∩
      (↑(extChartAt IB x.proj).symm ⁻¹' (trivializationAt F E x.proj).baseSet) ×ˢ univ
tactic: rw [FiberBundle.extChartAt, PartialEquiv.trans_target, Trivialization.target_eq, inter_prod]
state_before: 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
⊢ ((extChartAt IB x.proj).prod (PartialEquiv.refl F)).target ∩
      ↑((extChartAt IB x.proj).prod (PartialEquiv.refl F)).symm ⁻¹' (trivializationAt F E x.proj).baseSet ×ˢ univ =
    (extChartAt IB x.proj).target ×ˢ univ ∩
      (↑(extChartAt IB x.proj).symm ⁻¹' (trivializationAt F E x.proj).baseSet) ×ˢ univ
state_after: no goals
tactic: rfl