Theorem: SmoothBumpFunction.image_eq_inter_preimage_of_subset_support
File: Mathlib/Geometry/Manifold/BumpFunction.lean

Proof steps:
state_before: E : Type uE
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : FiniteDimensional 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
inst✝ : SmoothManifoldWithCorners I M
c : M
f : SmoothBumpFunction I c
x : M
s : Set M
hs : s ⊆ support ↑f
⊢ ↑(extChartAt I c) '' s = closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s
state_after: E : Type uE
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : FiniteDimensional 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
inst✝ : SmoothManifoldWithCorners I M
c : M
f : SmoothBumpFunction I c
x : M
s : Set M
hs : s ⊆ (extChartAt I c).source ∧ ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
⊢ ↑(extChartAt I c) '' s = closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s
tactic: rw [support_eq_inter_preimage, subset_inter_iff, ← extChartAt_source I, ← image_subset_iff] at hs
state_before: E : Type uE
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : FiniteDimensional 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
inst✝ : SmoothManifoldWithCorners I M
c : M
f : SmoothBumpFunction I c
x : M
s : Set M
hs : s ⊆ (extChartAt I c).source ∧ ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
⊢ ↑(extChartAt I c) '' s = closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s
state_after: case intro
E : Type uE
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : FiniteDimensional 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
inst✝ : SmoothManifoldWithCorners I M
c : M
f : SmoothBumpFunction I c
x : M
s : Set M
hse : s ⊆ (extChartAt I c).source
hsf : ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
⊢ ↑(extChartAt I c) '' s = closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s
tactic: cases' hs with hse hsf
state_before: case intro
E : Type uE
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : FiniteDimensional 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
inst✝ : SmoothManifoldWithCorners I M
c : M
f : SmoothBumpFunction I c
x : M
s : Set M
hse : s ⊆ (extChartAt I c).source
hsf : ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
⊢ ↑(extChartAt I c) '' s = closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s
state_after: case intro.h₁
E : Type uE
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : FiniteDimensional 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
inst✝ : SmoothManifoldWithCorners I M
c : M
f : SmoothBumpFunction I c
x : M
s : Set M
hse : s ⊆ (extChartAt I c).source
hsf : ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
⊢ ↑(extChartAt I c) '' s ⊆ closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s

case intro.h₂
E : Type uE
inst✝⁶ : NormedAddCommGroup E
inst✝⁵ : NormedSpace ℝ E
inst✝⁴ : FiniteDimensional 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
inst✝ : SmoothManifoldWithCorners I M
c : M
f : SmoothBumpFunction I c
x : M
s : Set M
hse : s ⊆ (extChartAt I c).source
hsf : ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
⊢ closedBall (↑(extChartAt I c) c) f.rOut ∩ range ↑I ∩ ↑(extChartAt I c).symm ⁻¹' s ⊆ ↑(extChartAt I c) '' s
tactic: apply Subset.antisymm