Theorem: StarAlgHom.ext_topologicalClosure
File: Mathlib/Topology/Algebra/StarSubalgebra.lean

Proof steps:
state_before: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
⊢ φ = ψ
state_after: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
⊢ ⇑φ = ⇑ψ
tactic: rw [DFunLike.ext'_iff]
state_before: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
⊢ ⇑φ = ⇑ψ
state_after: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
this : Dense (range ⇑(inclusion ⋯))
⊢ ⇑φ = ⇑ψ
tactic: have : Dense (Set.range <| inclusion (le_topologicalClosure S)) := by
    refine embedding_subtype_val.toInducing.dense_iff.2 fun x => ?_
    convert show ↑x ∈ closure (S : Set A) from x.prop
    rw [← Set.range_comp]
    exact
      Set.ext fun y =>
        ⟨by
          rintro ⟨y, rfl⟩
          exact y.prop, fun hy => ⟨⟨y, hy⟩, rfl⟩⟩
state_before: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
this : Dense (range ⇑(inclusion ⋯))
⊢ ⇑φ = ⇑ψ
state_after: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
this : Dense (range ⇑(inclusion ⋯))
⊢ EqOn (⇑φ) (⇑ψ) (range ⇑(inclusion ⋯))
tactic: refine Continuous.ext_on this hφ hψ ?_
state_before: R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
this : Dense (range ⇑(inclusion ⋯))
⊢ EqOn (⇑φ) (⇑ψ) (range ⇑(inclusion ⋯))
state_after: case intro
R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
this : Dense (range ⇑(inclusion ⋯))
x : ↥S
⊢ φ ((inclusion ⋯) x) = ψ ((inclusion ⋯) x)
tactic: rintro _ ⟨x, rfl⟩
state_before: case intro
R : Type u_1
A : Type u_2
B : Type u_3
inst✝¹³ : CommSemiring R
inst✝¹² : StarRing R
inst✝¹¹ : TopologicalSpace A
inst✝¹⁰ : Semiring A
inst✝⁹ : Algebra R A
inst✝⁸ : StarRing A
inst✝⁷ : StarModule R A
inst✝⁶ : TopologicalSemiring A
inst✝⁵ : ContinuousStar A
inst✝⁴ : TopologicalSpace B
inst✝³ : Semiring B
inst✝² : Algebra R B
inst✝¹ : StarRing B
inst✝ : T2Space B
S : StarSubalgebra R A
φ ψ : ↥S.topologicalClosure →⋆ₐ[R] B
hφ : Continuous ⇑φ
hψ : Continuous ⇑ψ
h : φ.comp (inclusion ⋯) = ψ.comp (inclusion ⋯)
this : Dense (range ⇑(inclusion ⋯))
x : ↥S
⊢ φ ((inclusion ⋯) x) = ψ ((inclusion ⋯) x)
state_after: no goals
tactic: simpa only using DFunLike.congr_fun h x