Module: Mathlib.Analysis.CStarAlgebra.ContinuousFunctionalCalculus.Unital

Goal state before:
pp: case f'
R : Type u_1
A : Type u_2
p : A → Prop
inst✝⁹ : CommSemiring R
inst✝⁸ : StarRing R
inst✝⁷ : MetricSpace R
inst✝⁶ : IsTopologicalSemiring R
inst✝⁵ : ContinuousStar R
inst✝⁴ : TopologicalSpace A
inst✝³ : Ring A
inst✝² : StarRing A
inst✝¹ : Algebra R A
instCFC : ContinuousFunctionalCalculus R A p
inst✝ : UniqueHom R A
g f : R → R
a : A
ha : p a
hg : ContinuousOn g (f '' spectrum R a)
hf : ContinuousOn f (spectrum R a)
this : ContinuousOn (g ∘ f) (spectrum R a)
sp_eq : spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ }) = f '' spectrum R a
⊢ C(↑(spectrum R a), ↑(spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ })))

pp: R : Type u_1
A : Type u_2
p : A → Prop
inst✝⁹ : CommSemiring R
inst✝⁸ : StarRing R
inst✝⁷ : MetricSpace R
inst✝⁶ : IsTopologicalSemiring R
inst✝⁵ : ContinuousStar R
inst✝⁴ : TopologicalSpace A
inst✝³ : Ring A
inst✝² : StarRing A
inst✝¹ : Algebra R A
instCFC : ContinuousFunctionalCalculus R A p
inst✝ : UniqueHom R A
g f : R → R
a : A
ha : p a
hg : ContinuousOn g (f '' spectrum R a)
hf : ContinuousOn f (spectrum R a)
this : ContinuousOn (g ∘ f) (spectrum R a)
sp_eq : spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ }) = f '' spectrum R a
⊢ (cfcHom ha) { toFun := (spectrum R a).domRestrict (g ∘ f), continuous_toFun := ⋯ } =
    (cfcHom ⋯)
      ({
            toFun :=
              (spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ })).domRestrict g,
            continuous_toFun := ⋯ }.comp
        ?f')

pp: case hff'
R : Type u_1
A : Type u_2
p : A → Prop
inst✝⁹ : CommSemiring R
inst✝⁸ : StarRing R
inst✝⁷ : MetricSpace R
inst✝⁶ : IsTopologicalSemiring R
inst✝⁵ : ContinuousStar R
inst✝⁴ : TopologicalSpace A
inst✝³ : Ring A
inst✝² : StarRing A
inst✝¹ : Algebra R A
instCFC : ContinuousFunctionalCalculus R A p
inst✝ : UniqueHom R A
g f : R → R
a : A
ha : p a
hg : ContinuousOn g (f '' spectrum R a)
hf : ContinuousOn f (spectrum R a)
this : ContinuousOn (g ∘ f) (spectrum R a)
sp_eq : spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ }) = f '' spectrum R a
⊢ ∀ (x : ↑(spectrum R a)), { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ } x = ↑(?f' x)

Tactic:
· exact ContinuousMap.mk _ <| hf.domRestrict.codRestrict fun x ↦ by rw [sp_eq]; use x.1; simp

Goal state after:
R : Type u_1
A : Type u_2
p : A → Prop
inst✝⁹ : CommSemiring R
inst✝⁸ : StarRing R
inst✝⁷ : MetricSpace R
inst✝⁶ : IsTopologicalSemiring R
inst✝⁵ : ContinuousStar R
inst✝⁴ : TopologicalSpace A
inst✝³ : Ring A
inst✝² : StarRing A
inst✝¹ : Algebra R A
instCFC : ContinuousFunctionalCalculus R A p
inst✝ : UniqueHom R A
g f : R → R
a : A
ha : p a
hg : ContinuousOn g (f '' spectrum R a)
hf : ContinuousOn f (spectrum R a)
this : ContinuousOn (g ∘ f) (spectrum R a)
sp_eq : spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ }) = f '' spectrum R a
⊢ (cfcHom ha) { toFun := (spectrum R a).domRestrict (g ∘ f), continuous_toFun := ⋯ } =
    (cfcHom ⋯)
      ({
            toFun :=
              (spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ })).domRestrict g,
            continuous_toFun := ⋯ }.comp
        {
          toFun :=
            Set.codRestrict ((spectrum R a).domRestrict f)
              (spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ })) ⋯,
          continuous_toFun := ⋯ })

case hff'
R : Type u_1
A : Type u_2
p : A → Prop
inst✝⁹ : CommSemiring R
inst✝⁸ : StarRing R
inst✝⁷ : MetricSpace R
inst✝⁶ : IsTopologicalSemiring R
inst✝⁵ : ContinuousStar R
inst✝⁴ : TopologicalSpace A
inst✝³ : Ring A
inst✝² : StarRing A
inst✝¹ : Algebra R A
instCFC : ContinuousFunctionalCalculus R A p
inst✝ : UniqueHom R A
g f : R → R
a : A
ha : p a
hg : ContinuousOn g (f '' spectrum R a)
hf : ContinuousOn f (spectrum R a)
this : ContinuousOn (g ∘ f) (spectrum R a)
sp_eq : spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ }) = f '' spectrum R a
⊢ ∀ (x : ↑(spectrum R a)),
    { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ } x =
      ↑({
            toFun :=
              Set.codRestrict ((spectrum R a).domRestrict f)
                (spectrum R ((cfcHom ⋯) { toFun := (spectrum R a).domRestrict f, continuous_toFun := ⋯ })) ⋯,
            continuous_toFun := ⋯ }
          x)