Module: Mathlib.Geometry.Manifold.ContMDiff.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
E' : Type u_5
inst✝¹⁰ : NormedAddCommGroup E'
inst✝⁹ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝⁸ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝⁷ : TopologicalSpace M'
E'' : Type u_8
inst✝⁶ : NormedAddCommGroup E''
inst✝⁵ : NormedSpace 𝕜 E''
H'' : Type u_9
inst✝⁴ : TopologicalSpace H''
I'' : ModelWithCorners 𝕜 E'' H''
M'' : Type u_10
inst✝³ : TopologicalSpace M''
inst✝² : ChartedSpace H M
inst✝¹ : ChartedSpace H' M'
inst✝ : ChartedSpace H'' M''
f : M → M'
s : Set M
n : ℕ∞ω
t : Set M'
g : M' → M''
x : M
st : MapsTo f s t
e : PartialEquiv M E := extChartAt I x
e' : PartialEquiv M' E' := extChartAt I' (f x)
hg :
  ContinuousWithinAt g t (f x) ∧
    ContDiffWithinAt 𝕜 n (↑(extChartAt I'' (g (f x))) ∘ g ∘ ↑e'.symm) (↑e'.symm ⁻¹' t ∩ range ↑I')
      (writtenInExtChartAt I I' x f (↑e x))
hf : ContinuousWithinAt f s x ∧ ContDiffWithinAt 𝕜 n (↑e' ∘ f ∘ ↑e.symm) (↑e.symm ⁻¹' s ∩ range ↑I) (↑e x)
this : ↑e' (f x) = writtenInExtChartAt I I' x f (↑e x)
A : ∀ᶠ (y : E) in 𝓝[↑e.symm ⁻¹' s ∩ range ↑I] ↑e x, f (↑e.symm y) ∈ t ∧ f (↑e.symm y) ∈ e'.source
⊢ ContDiffWithinAt 𝕜 n (↑(extChartAt I'' ((g ∘ f) x)) ∘ (g ∘ f) ∘ ↑e.symm) (↑e.symm ⁻¹' s ∩ range ↑I) (↑e x)

Tactic:
refine ((hg.2.comp _ (hf.2.mono inter_subset_right)
      ((mapsTo_preimage _ _).mono_left inter_subset_left)).mono_of_mem_nhdsWithin
      (inter_mem ?_ self_mem_nhdsWithin)).congr_of_eventuallyEq ?_ ?_

Goal state after:
case refine_1
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
E' : Type u_5
inst✝¹⁰ : NormedAddCommGroup E'
inst✝⁹ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝⁸ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝⁷ : TopologicalSpace M'
E'' : Type u_8
inst✝⁶ : NormedAddCommGroup E''
inst✝⁵ : NormedSpace 𝕜 E''
H'' : Type u_9
inst✝⁴ : TopologicalSpace H''
I'' : ModelWithCorners 𝕜 E'' H''
M'' : Type u_10
inst✝³ : TopologicalSpace M''
inst✝² : ChartedSpace H M
inst✝¹ : ChartedSpace H' M'
inst✝ : ChartedSpace H'' M''
f : M → M'
s : Set M
n : ℕ∞ω
t : Set M'
g : M' → M''
x : M
st : MapsTo f s t
e : PartialEquiv M E := extChartAt I x
e' : PartialEquiv M' E' := extChartAt I' (f x)
hg :
  ContinuousWithinAt g t (f x) ∧
    ContDiffWithinAt 𝕜 n (↑(extChartAt I'' (g (f x))) ∘ g ∘ ↑e'.symm) (↑e'.symm ⁻¹' t ∩ range ↑I')
      (writtenInExtChartAt I I' x f (↑e x))
hf : ContinuousWithinAt f s x ∧ ContDiffWithinAt 𝕜 n (↑e' ∘ f ∘ ↑e.symm) (↑e.symm ⁻¹' s ∩ range ↑I) (↑e x)
this : ↑e' (f x) = writtenInExtChartAt I I' x f (↑e x)
A : ∀ᶠ (y : E) in 𝓝[↑e.symm ⁻¹' s ∩ range ↑I] ↑e x, f (↑e.symm y) ∈ t ∧ f (↑e.symm y) ∈ e'.source
⊢ writtenInExtChartAt I I' x f ⁻¹' (↑e'.symm ⁻¹' t ∩ range ↑I') ∈ 𝓝[↑e.symm ⁻¹' s ∩ range ↑I] ↑e x

case refine_2
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
E' : Type u_5
inst✝¹⁰ : NormedAddCommGroup E'
inst✝⁹ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝⁸ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝⁷ : TopologicalSpace M'
E'' : Type u_8
inst✝⁶ : NormedAddCommGroup E''
inst✝⁵ : NormedSpace 𝕜 E''
H'' : Type u_9
inst✝⁴ : TopologicalSpace H''
I'' : ModelWithCorners 𝕜 E'' H''
M'' : Type u_10
inst✝³ : TopologicalSpace M''
inst✝² : ChartedSpace H M
inst✝¹ : ChartedSpace H' M'
inst✝ : ChartedSpace H'' M''
f : M → M'
s : Set M
n : ℕ∞ω
t : Set M'
g : M' → M''
x : M
st : MapsTo f s t
e : PartialEquiv M E := extChartAt I x
e' : PartialEquiv M' E' := extChartAt I' (f x)
hg :
  ContinuousWithinAt g t (f x) ∧
    ContDiffWithinAt 𝕜 n (↑(extChartAt I'' (g (f x))) ∘ g ∘ ↑e'.symm) (↑e'.symm ⁻¹' t ∩ range ↑I')
      (writtenInExtChartAt I I' x f (↑e x))
hf : ContinuousWithinAt f s x ∧ ContDiffWithinAt 𝕜 n (↑e' ∘ f ∘ ↑e.symm) (↑e.symm ⁻¹' s ∩ range ↑I) (↑e x)
this : ↑e' (f x) = writtenInExtChartAt I I' x f (↑e x)
A : ∀ᶠ (y : E) in 𝓝[↑e.symm ⁻¹' s ∩ range ↑I] ↑e x, f (↑e.symm y) ∈ t ∧ f (↑e.symm y) ∈ e'.source
⊢ ↑(extChartAt I'' ((g ∘ f) x)) ∘ (g ∘ f) ∘ ↑e.symm =ᶠ[𝓝[↑e.symm ⁻¹' s ∩ range ↑I] ↑e x]
    (↑(extChartAt I'' (g (f x))) ∘ g ∘ ↑e'.symm) ∘ writtenInExtChartAt I I' x f

case refine_3
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
E' : Type u_5
inst✝¹⁰ : NormedAddCommGroup E'
inst✝⁹ : NormedSpace 𝕜 E'
H' : Type u_6
inst✝⁸ : TopologicalSpace H'
I' : ModelWithCorners 𝕜 E' H'
M' : Type u_7
inst✝⁷ : TopologicalSpace M'
E'' : Type u_8
inst✝⁶ : NormedAddCommGroup E''
inst✝⁵ : NormedSpace 𝕜 E''
H'' : Type u_9
inst✝⁴ : TopologicalSpace H''
I'' : ModelWithCorners 𝕜 E'' H''
M'' : Type u_10
inst✝³ : TopologicalSpace M''
inst✝² : ChartedSpace H M
inst✝¹ : ChartedSpace H' M'
inst✝ : ChartedSpace H'' M''
f : M → M'
s : Set M
n : ℕ∞ω
t : Set M'
g : M' → M''
x : M
st : MapsTo f s t
e : PartialEquiv M E := extChartAt I x
e' : PartialEquiv M' E' := extChartAt I' (f x)
hg :
  ContinuousWithinAt g t (f x) ∧
    ContDiffWithinAt 𝕜 n (↑(extChartAt I'' (g (f x))) ∘ g ∘ ↑e'.symm) (↑e'.symm ⁻¹' t ∩ range ↑I')
      (writtenInExtChartAt I I' x f (↑e x))
hf : ContinuousWithinAt f s x ∧ ContDiffWithinAt 𝕜 n (↑e' ∘ f ∘ ↑e.symm) (↑e.symm ⁻¹' s ∩ range ↑I) (↑e x)
this : ↑e' (f x) = writtenInExtChartAt I I' x f (↑e x)
A : ∀ᶠ (y : E) in 𝓝[↑e.symm ⁻¹' s ∩ range ↑I] ↑e x, f (↑e.symm y) ∈ t ∧ f (↑e.symm y) ∈ e'.source
⊢ (↑(extChartAt I'' ((g ∘ f) x)) ∘ (g ∘ f) ∘ ↑e.symm) (↑e x) =
    ((↑(extChartAt I'' (g (f x))) ∘ g ∘ ↑e'.symm) ∘ writtenInExtChartAt I I' x f) (↑e x)