Theorem: Trivialization.continuousAt_of_comp_left
File: Mathlib/Topology/FiberBundle/Trivialization.lean

tactic: rw [e.continuousAt_iff_continuousAt_comp_left]
state_before: ι : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
Z : Type u_5
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace F
proj : Z → B
inst✝² : TopologicalSpace Z
inst✝¹ : TopologicalSpace (TotalSpace F E)
e✝ : Trivialization F proj
x✝ : Z
X : Type u_6
inst✝ : TopologicalSpace X
f : X → Z
x : X
e : Trivialization F proj
hf_proj : ContinuousAt (proj ∘ f) x
he : proj (f x) ∈ e.baseSet
hf : ContinuousAt (↑e ∘ f) x
⊢ ContinuousAt f x
state_after: ι : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
Z : Type u_5
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace F
proj : Z → B
inst✝² : TopologicalSpace Z
inst✝¹ : TopologicalSpace (TotalSpace F E)
e✝ : Trivialization F proj
x✝ : Z
X : Type u_6
inst✝ : TopologicalSpace X
f : X → Z
x : X
e : Trivialization F proj
hf_proj : ContinuousAt (proj ∘ f) x
he : proj (f x) ∈ e.baseSet
hf : ContinuousAt (↑e ∘ f) x
⊢ ContinuousAt (↑e.toPartialHomeomorph ∘ f) x

ι : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
Z : Type u_5
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace F
proj : Z → B
inst✝² : TopologicalSpace Z
inst✝¹ : TopologicalSpace (TotalSpace F E)
e✝ : Trivialization F proj
x✝ : Z
X : Type u_6
inst✝ : TopologicalSpace X
f : X → Z
x : X
e : Trivialization F proj
hf_proj : ContinuousAt (proj ∘ f) x
he : proj (f x) ∈ e.baseSet
hf : ContinuousAt (↑e ∘ f) x
⊢ f ⁻¹' e.source ∈ 𝓝 x

tactic: rw [e.source_eq, ← preimage_comp]
state_before: ι : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
Z : Type u_5
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace F
proj : Z → B
inst✝² : TopologicalSpace Z
inst✝¹ : TopologicalSpace (TotalSpace F E)
e✝ : Trivialization F proj
x✝ : Z
X : Type u_6
inst✝ : TopologicalSpace X
f : X → Z
x : X
e : Trivialization F proj
hf_proj : ContinuousAt (proj ∘ f) x
he : proj (f x) ∈ e.baseSet
hf : ContinuousAt (↑e ∘ f) x
⊢ f ⁻¹' e.source ∈ 𝓝 x
state_after: ι : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
Z : Type u_5
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace F
proj : Z → B
inst✝² : TopologicalSpace Z
inst✝¹ : TopologicalSpace (TotalSpace F E)
e✝ : Trivialization F proj
x✝ : Z
X : Type u_6
inst✝ : TopologicalSpace X
f : X → Z
x : X
e : Trivialization F proj
hf_proj : ContinuousAt (proj ∘ f) x
he : proj (f x) ∈ e.baseSet
hf : ContinuousAt (↑e ∘ f) x
⊢ proj ∘ f ⁻¹' e.baseSet ∈ 𝓝 x

tactic: exact hf_proj.preimage_mem_nhds (e.open_baseSet.mem_nhds he)
state_before: ι : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
Z : Type u_5
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace F
proj : Z → B
inst✝² : TopologicalSpace Z
inst✝¹ : TopologicalSpace (TotalSpace F E)
e✝ : Trivialization F proj
x✝ : Z
X : Type u_6
inst✝ : TopologicalSpace X
f : X → Z
x : X
e : Trivialization F proj
hf_proj : ContinuousAt (proj ∘ f) x
he : proj (f x) ∈ e.baseSet
hf : ContinuousAt (↑e ∘ f) x
⊢ proj ∘ f ⁻¹' e.baseSet ∈ 𝓝 x
state_after: no goals

tactic: exact hf
state_before: ι : Type u_1
B : Type u_2
F : Type u_3
E : B → Type u_4
Z : Type u_5
inst✝⁴ : TopologicalSpace B
inst✝³ : TopologicalSpace F
proj : Z → B
inst✝² : TopologicalSpace Z
inst✝¹ : TopologicalSpace (TotalSpace F E)
e✝ : Trivialization F proj
x✝ : Z
X : Type u_6
inst✝ : TopologicalSpace X
f : X → Z
x : X
e : Trivialization F proj
hf_proj : ContinuousAt (proj ∘ f) x
he : proj (f x) ∈ e.baseSet
hf : ContinuousAt (↑e ∘ f) x
⊢ ContinuousAt (↑e.toPartialHomeomorph ∘ f) x
state_after: no goals