Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Continuity

Goal state before:
pp: case refine_1
X : Type u_1
𝕜 : Type u_2
A : Type u_3
p : A → Prop
inst✝⁹ : RCLike 𝕜
inst✝⁸ : NonUnitalNormedRing A
inst✝⁷ : StarRing A
inst✝⁶ : NormedSpace 𝕜 A
inst✝⁵ : IsScalarTower 𝕜 A A
inst✝⁴ : SMulCommClass 𝕜 A A
inst✝³ : ContinuousStar A
inst✝² : NonUnitalIsometricContinuousFunctionalCalculus 𝕜 A p
inst✝¹ : CompleteSpace A
inst✝ : TopologicalSpace X
s : Set 𝕜
f : 𝕜 → 𝕜
a : X → A
t : Set X
hs : s ∈ 𝓝ˢ (⋃ x ∈ t, quasispectrum 𝕜 (a x))
ha_cont : ContinuousOn a t
ha' : ∀ x ∈ t, p (a x)
hf : ContinuousOn f s
hf0 : f 0 = 0
hs' : ∀ i ∈ t, s ∈ 𝓝ˢ (quasispectrum 𝕜 (a i))
S : ↑t → Set 𝕜
hS₁ : ∀ (x : ↑t), IsCompact (S x)
hS₂ : ∀ (x : ↑t), ∀ᶠ (x' : A) in 𝓝 (a ↑x), quasispectrum 𝕜 x' ⊆ S x
hS₃ : ∀ (x : ↑t), S x ⊆ s
⊢ ∀ x₀ ∈ t, ∀ᶠ (x : X) in 𝓝[t] x₀, quasispectrum 𝕜 (a x) ⊆ if hx : x₀ ∈ t then S ⟨x₀, hx⟩ else ∅

pp: case refine_2
X : Type u_1
𝕜 : Type u_2
A : Type u_3
p : A → Prop
inst✝⁹ : RCLike 𝕜
inst✝⁸ : NonUnitalNormedRing A
inst✝⁷ : StarRing A
inst✝⁶ : NormedSpace 𝕜 A
inst✝⁵ : IsScalarTower 𝕜 A A
inst✝⁴ : SMulCommClass 𝕜 A A
inst✝³ : ContinuousStar A
inst✝² : NonUnitalIsometricContinuousFunctionalCalculus 𝕜 A p
inst✝¹ : CompleteSpace A
inst✝ : TopologicalSpace X
s : Set 𝕜
f : 𝕜 → 𝕜
a : X → A
t : Set X
hs : s ∈ 𝓝ˢ (⋃ x ∈ t, quasispectrum 𝕜 (a x))
ha_cont : ContinuousOn a t
ha' : ∀ x ∈ t, p (a x)
hf : ContinuousOn f s
hf0 : f 0 = 0
hs' : ∀ i ∈ t, s ∈ 𝓝ˢ (quasispectrum 𝕜 (a i))
S : ↑t → Set 𝕜
hS₁ : ∀ (x : ↑t), IsCompact (S x)
hS₂ : ∀ (x : ↑t), ∀ᶠ (x' : A) in 𝓝 (a ↑x), quasispectrum 𝕜 x' ⊆ S x
hS₃ : ∀ (x : ↑t), S x ⊆ s
⊢ ∀ x ∈ t, ContinuousOn f (if hx : x ∈ t then S ⟨x, hx⟩ else ∅)

Tactic:
all_goals simp +contextual only [↓reduceDIte]

Goal state after:
case refine_1
X : Type u_1
𝕜 : Type u_2
A : Type u_3
p : A → Prop
inst✝⁹ : RCLike 𝕜
inst✝⁸ : NonUnitalNormedRing A
inst✝⁷ : StarRing A
inst✝⁶ : NormedSpace 𝕜 A
inst✝⁵ : IsScalarTower 𝕜 A A
inst✝⁴ : SMulCommClass 𝕜 A A
inst✝³ : ContinuousStar A
inst✝² : NonUnitalIsometricContinuousFunctionalCalculus 𝕜 A p
inst✝¹ : CompleteSpace A
inst✝ : TopologicalSpace X
s : Set 𝕜
f : 𝕜 → 𝕜
a : X → A
t : Set X
hs : s ∈ 𝓝ˢ (⋃ x ∈ t, quasispectrum 𝕜 (a x))
ha_cont : ContinuousOn a t
ha' : ∀ x ∈ t, p (a x)
hf : ContinuousOn f s
hf0 : f 0 = 0
hs' : ∀ i ∈ t, s ∈ 𝓝ˢ (quasispectrum 𝕜 (a i))
S : ↑t → Set 𝕜
hS₁ : ∀ (x : ↑t), IsCompact (S x)
hS₂ : ∀ (x : ↑t), ∀ᶠ (x' : A) in 𝓝 (a ↑x), quasispectrum 𝕜 x' ⊆ S x
hS₃ : ∀ (x : ↑t), S x ⊆ s
⊢ ∀ (x₀ : X) (a_1 : x₀ ∈ t), ∀ᶠ (x : X) in 𝓝[t] x₀, quasispectrum 𝕜 (a x) ⊆ S ⟨x₀, ⋯⟩

case refine_2
X : Type u_1
𝕜 : Type u_2
A : Type u_3
p : A → Prop
inst✝⁹ : RCLike 𝕜
inst✝⁸ : NonUnitalNormedRing A
inst✝⁷ : StarRing A
inst✝⁶ : NormedSpace 𝕜 A
inst✝⁵ : IsScalarTower 𝕜 A A
inst✝⁴ : SMulCommClass 𝕜 A A
inst✝³ : ContinuousStar A
inst✝² : NonUnitalIsometricContinuousFunctionalCalculus 𝕜 A p
inst✝¹ : CompleteSpace A
inst✝ : TopologicalSpace X
s : Set 𝕜
f : 𝕜 → 𝕜
a : X → A
t : Set X
hs : s ∈ 𝓝ˢ (⋃ x ∈ t, quasispectrum 𝕜 (a x))
ha_cont : ContinuousOn a t
ha' : ∀ x ∈ t, p (a x)
hf : ContinuousOn f s
hf0 : f 0 = 0
hs' : ∀ i ∈ t, s ∈ 𝓝ˢ (quasispectrum 𝕜 (a i))
S : ↑t → Set 𝕜
hS₁ : ∀ (x : ↑t), IsCompact (S x)
hS₂ : ∀ (x : ↑t), ∀ᶠ (x' : A) in 𝓝 (a ↑x), quasispectrum 𝕜 x' ⊆ S x
hS₃ : ∀ (x : ↑t), S x ⊆ s
⊢ ∀ (x : X) (a : x ∈ t), ContinuousOn f (S ⟨x, ⋯⟩)