Theorem: LocallyFinite.continuousOn_iUnion'
File: Mathlib/Topology/LocallyFinite.lean

tactic: rintro x -
state_before: ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
⊢ ContinuousOn g (⋃ i, f i)
state_after: ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
⊢ ContinuousWithinAt g (⋃ i, f i) x

tactic: rw [ContinuousWithinAt, hf.nhdsWithin_iUnion, tendsto_iSup]
state_before: ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
⊢ ContinuousWithinAt g (⋃ i, f i) x
state_after: ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
⊢ ∀ (i : ι), Tendsto g (𝓝[f i] x) (𝓝 (g x))

tactic: intro i
state_before: ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
⊢ ∀ (i : ι), Tendsto g (𝓝[f i] x) (𝓝 (g x))
state_after: ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))

tactic: by_cases hx : x ∈ closure (f i)
state_before: ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))
state_after: case pos
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : x ∈ closure (f i)
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))

case neg
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : x ∉ closure (f i)
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))

tactic: exact hc i _ hx
state_before: case pos
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : x ∈ closure (f i)
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))
state_after: no goals

tactic: rw [mem_closure_iff_nhdsWithin_neBot, not_neBot] at hx
state_before: case neg
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : x ∉ closure (f i)
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))
state_after: case neg
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : 𝓝[f i] x = ⊥
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))

tactic: rw [hx]
state_before: case neg
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : 𝓝[f i] x = ⊥
⊢ Tendsto g (𝓝[f i] x) (𝓝 (g x))
state_after: case neg
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : 𝓝[f i] x = ⊥
⊢ Tendsto g ⊥ (𝓝 (g x))

tactic: exact tendsto_bot
state_before: case neg
ι : Type u_1
ι' : Type u_2
α : Type u_3
X : Type u_4
Y : Type u_5
inst✝¹ : TopologicalSpace X
inst✝ : TopologicalSpace Y
f g✝ : ι → Set X
g : X → Y
hf : LocallyFinite f
hc : ∀ (i : ι), ∀ x ∈ closure (f i), ContinuousWithinAt g (f i) x
x : X
i : ι
hx : 𝓝[f i] x = ⊥
⊢ Tendsto g ⊥ (𝓝 (g x))
state_after: no goals