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

tactic: set e := extChartAt I c
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
hsc : IsClosed s
hs : s ⊆ support ↑f
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r
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
hsc : IsClosed s
hs : s ⊆ support ↑f
e : PartialEquiv M E := extChartAt I c
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r

tactic: have : IsClosed (e '' s) := f.isClosed_image_of_isClosed hsc 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
hsc : IsClosed s
hs : s ⊆ support ↑f
e : PartialEquiv M E := extChartAt I c
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r
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
hsc : IsClosed s
hs : s ⊆ support ↑f
e : PartialEquiv M E := extChartAt I c
this : IsClosed (↑e '' s)
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r

tactic: rw [support_eq_inter_preimage, subset_inter_iff, ← 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
hsc : IsClosed s
hs : s ⊆ support ↑f
e : PartialEquiv M E := extChartAt I c
this : IsClosed (↑e '' s)
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r
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
hsc : IsClosed s
hs : s ⊆ (chartAt H c).source ∧ ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
e : PartialEquiv M E := extChartAt I c
this : IsClosed (↑e '' s)
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r

tactic: rcases exists_pos_lt_subset_ball f.rOut_pos this hs.2 with ⟨r, hrR, hr⟩
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
hsc : IsClosed s
hs : s ⊆ (chartAt H c).source ∧ ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
e : PartialEquiv M E := extChartAt I c
this : IsClosed (↑e '' s)
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r
state_after: case intro.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
hsc : IsClosed s
hs : s ⊆ (chartAt H c).source ∧ ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
e : PartialEquiv M E := extChartAt I c
this : IsClosed (↑e '' s)
r : ℝ
hrR : r ∈ Ioo 0 f.rOut
hr : ↑e '' s ⊆ ball (↑(extChartAt I c) c) r
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r

tactic: exact ⟨r, hrR, subset_inter hs.1 (image_subset_iff.1 hr)⟩
state_before: case intro.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
hsc : IsClosed s
hs : s ⊆ (chartAt H c).source ∧ ↑(extChartAt I c) '' s ⊆ ball (↑(extChartAt I c) c) f.rOut
e : PartialEquiv M E := extChartAt I c
this : IsClosed (↑e '' s)
r : ℝ
hrR : r ∈ Ioo 0 f.rOut
hr : ↑e '' s ⊆ ball (↑(extChartAt I c) c) r
⊢ ∃ r ∈ Ioo 0 f.rOut, s ⊆ (chartAt H c).source ∩ ↑(extChartAt I c) ⁻¹' ball (↑(extChartAt I c) c) r
state_after: no goals