Documentation

Mathlib.Algebra.Star.Subalgebra

Star subalgebras #

A *-subalgebra is a subalgebra of a *-algebra which is closed under *.

The centralizer of a *-closed set is a *-subalgebra.

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structure StarSubalgebra (R : Type u) (A : Type v) [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] extends Subalgebra :
Type v

A *-subalgebra is a subalgebra of a *-algebra which is closed under *.

  • carrier : Set A
  • mul_mem' : ∀ {a b : A}, a ∈ self.carrier → b ∈ self.carrier → a * b ∈ self.carrier
  • one_mem' : 1 ∈ self.carrier
  • add_mem' : ∀ {a b : A}, a ∈ self.carrier → b ∈ self.carrier → a + b ∈ self.carrier
  • zero_mem' : 0 ∈ self.carrier
  • algebraMap_mem' : ∀ (r : R), (algebraMap R A) r ∈ self.carrier
  • star_mem' : ∀ {a : A}, a ∈ self.carrier → star a ∈ self.carrier

    The carrier is closed under the star operation.

Instances For
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instance StarSubalgebra.setLike {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] :
SetLike (StarSubalgebra R A) A
Equations
  • StarSubalgebra.setLike = { coe := fun (S : StarSubalgebra R A) => S.carrier, coe_injective' := ⋯ }
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instance StarSubalgebra.starMemClass {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] :
StarMemClass (StarSubalgebra R A) A
Equations
  • ⋯ = ⋯
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instance StarSubalgebra.subsemiringClass {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] :
SubsemiringClass (StarSubalgebra R A) A
Equations
  • ⋯ = ⋯
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instance StarSubalgebra.smulMemClass {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] :
SMulMemClass (StarSubalgebra R A) R A
Equations
  • ⋯ = ⋯
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instance StarSubalgebra.subringClass {R : Type u_6} {A : Type u_7} [CommRing R] [StarRing R] [Ring A] [StarRing A] [Algebra R A] [StarModule R A] :
SubringClass (StarSubalgebra R A) A
Equations
  • ⋯ = ⋯
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instance StarSubalgebra.starRing {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (s : StarSubalgebra R A) :
StarRing ↥s
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instance StarSubalgebra.algebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (s : StarSubalgebra R A) :
Algebra R ↥s
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instance StarSubalgebra.starModule {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (s : StarSubalgebra R A) :
StarModule R ↥s
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  • ⋯ = ⋯
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@[simp]
theorem StarSubalgebra.mem_carrier {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {s : StarSubalgebra R A} {x : A} :
x ∈ s.carrier ↔ x ∈ s
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theorem StarSubalgebra.ext {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S : StarSubalgebra R A} {T : StarSubalgebra R A} (h : ∀ (x : A), x ∈ S ↔ x ∈ T) :
S = T
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@[simp]
theorem StarSubalgebra.coe_mk {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : Subalgebra R A) (h : ∀ {a : A}, a ∈ S.carrier → star a ∈ S.carrier) :
↑{ toSubalgebra := S, star_mem' := h } = ↑S
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@[simp]
theorem StarSubalgebra.mem_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S : StarSubalgebra R A} {x : A} :
x ∈ S.toSubalgebra ↔ x ∈ S
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@[simp]
theorem StarSubalgebra.coe_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
↑S.toSubalgebra = ↑S
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theorem StarSubalgebra.toSubalgebra_injective {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] :
Function.Injective StarSubalgebra.toSubalgebra
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theorem StarSubalgebra.toSubalgebra_inj {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S : StarSubalgebra R A} {U : StarSubalgebra R A} :
S.toSubalgebra = U.toSubalgebra ↔ S = U
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theorem StarSubalgebra.toSubalgebra_le_iff {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S₁ : StarSubalgebra R A} {S₂ : StarSubalgebra R A} :
S₁.toSubalgebra ≤ S₂.toSubalgebra ↔ S₁ ≤ S₂
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def StarSubalgebra.copy {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) (s : Set A) (hs : s = ↑S) :
StarSubalgebra R A

Copy of a star subalgebra with a new carrier equal to the old one. Useful to fix definitional equalities.

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@[simp]
theorem StarSubalgebra.coe_copy {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) (s : Set A) (hs : s = ↑S) :
↑(StarSubalgebra.copy S s hs) = s
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theorem StarSubalgebra.copy_eq {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) (s : Set A) (hs : s = ↑S) :
StarSubalgebra.copy S s hs = S
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theorem StarSubalgebra.algebraMap_mem {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) (r : R) :
(algebraMap R A) r ∈ S
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theorem StarSubalgebra.rangeS_le {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
RingHom.rangeS (algebraMap R A) ≤ S.toSubsemiring
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theorem StarSubalgebra.range_subset {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
Set.range ⇑(algebraMap R A) ⊆ ↑S
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theorem StarSubalgebra.range_le {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
Set.range ⇑(algebraMap R A) ≤ ↑S
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theorem StarSubalgebra.smul_mem {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) {x : A} (hx : x ∈ S) (r : R) :
r • x ∈ S
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def StarSubalgebra.subtype {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
↥S →⋆ₐ[R] A

Embedding of a subalgebra into the algebra.

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  • One or more equations did not get rendered due to their size.
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@[simp]
theorem StarSubalgebra.coe_subtype {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
⇑(StarSubalgebra.subtype S) = Subtype.val
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theorem StarSubalgebra.subtype_apply {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) (x : ↥S) :
(StarSubalgebra.subtype S) x = ↑x
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@[simp]
theorem StarSubalgebra.toSubalgebra_subtype {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
Subalgebra.val S.toSubalgebra = (StarSubalgebra.subtype S).toAlgHom
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@[simp]
theorem StarSubalgebra.inclusion_apply {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S₁ : StarSubalgebra R A} {S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂) :
∀ (a : ↥S₁), (StarSubalgebra.inclusion h) a = Subtype.map id h a
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def StarSubalgebra.inclusion {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S₁ : StarSubalgebra R A} {S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂) :
↥S₁ →⋆ₐ[R] ↥S₂

The inclusion map between StarSubalgebras given by Subtype.map id as a StarAlgHom.

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  • One or more equations did not get rendered due to their size.
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theorem StarSubalgebra.inclusion_injective {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S₁ : StarSubalgebra R A} {S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂) :
Function.Injective ⇑(StarSubalgebra.inclusion h)
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@[simp]
theorem StarSubalgebra.subtype_comp_inclusion {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {S₁ : StarSubalgebra R A} {S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂) :
StarAlgHom.comp (StarSubalgebra.subtype S₂) (StarSubalgebra.inclusion h) = StarSubalgebra.subtype S₁
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def StarSubalgebra.map {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] (f : A →⋆ₐ[R] B) (S : StarSubalgebra R A) :
StarSubalgebra R B

Transport a star subalgebra via a star algebra homomorphism.

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theorem StarSubalgebra.map_mono {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] {S₁ : StarSubalgebra R A} {S₂ : StarSubalgebra R A} {f : A →⋆ₐ[R] B} :
S₁ ≤ S₂ → StarSubalgebra.map f S₁ ≤ StarSubalgebra.map f S₂
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theorem StarSubalgebra.map_injective {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] {f : A →⋆ₐ[R] B} (hf : Function.Injective ⇑f) :
Function.Injective (StarSubalgebra.map f)
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@[simp]
theorem StarSubalgebra.map_id {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
StarSubalgebra.map (StarAlgHom.id R A) S = S
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theorem StarSubalgebra.map_map {R : Type u_2} {A : Type u_3} {B : Type u_4} {C : Type u_5} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] [Semiring C] [StarRing C] [Algebra R C] [StarModule R C] (S : StarSubalgebra R A) (g : B →⋆ₐ[R] C) (f : A →⋆ₐ[R] B) :
StarSubalgebra.map g (StarSubalgebra.map f S) = StarSubalgebra.map (StarAlgHom.comp g f) S
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@[simp]
theorem StarSubalgebra.mem_map {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] {S : StarSubalgebra R A} {f : A →⋆ₐ[R] B} {y : B} :
y ∈ StarSubalgebra.map f S ↔ ∃ x ∈ S, f x = y
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theorem StarSubalgebra.map_toSubalgebra {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] {S : StarSubalgebra R A} {f : A →⋆ₐ[R] B} :
(StarSubalgebra.map f S).toSubalgebra = Subalgebra.map f.toAlgHom S.toSubalgebra
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@[simp]
theorem StarSubalgebra.coe_map {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] (S : StarSubalgebra R A) (f : A →⋆ₐ[R] B) :
↑(StarSubalgebra.map f S) = ⇑f '' ↑S
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def StarSubalgebra.comap {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] (f : A →⋆ₐ[R] B) (S : StarSubalgebra R B) :
StarSubalgebra R A

Preimage of a star subalgebra under a star algebra homomorphism.

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theorem StarSubalgebra.map_le_iff_le_comap {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] {S : StarSubalgebra R A} {f : A →⋆ₐ[R] B} {U : StarSubalgebra R B} :
StarSubalgebra.map f S ≤ U ↔ S ≤ StarSubalgebra.comap f U
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theorem StarSubalgebra.gc_map_comap {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] (f : A →⋆ₐ[R] B) :
GaloisConnection (StarSubalgebra.map f) (StarSubalgebra.comap f)
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theorem StarSubalgebra.comap_mono {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] {S₁ : StarSubalgebra R B} {S₂ : StarSubalgebra R B} {f : A →⋆ₐ[R] B} :
S₁ ≤ S₂ → StarSubalgebra.comap f S₁ ≤ StarSubalgebra.comap f S₂
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theorem StarSubalgebra.comap_injective {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] {f : A →⋆ₐ[R] B} (hf : Function.Surjective ⇑f) :
Function.Injective (StarSubalgebra.comap f)
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@[simp]
theorem StarSubalgebra.comap_id {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (S : StarSubalgebra R A) :
StarSubalgebra.comap (StarAlgHom.id R A) S = S
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theorem StarSubalgebra.comap_comap {R : Type u_2} {A : Type u_3} {B : Type u_4} {C : Type u_5} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] [Semiring C] [StarRing C] [Algebra R C] [StarModule R C] (S : StarSubalgebra R C) (g : B →⋆ₐ[R] C) (f : A →⋆ₐ[R] B) :
StarSubalgebra.comap f (StarSubalgebra.comap g S) = StarSubalgebra.comap (StarAlgHom.comp g f) S
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@[simp]
theorem StarSubalgebra.mem_comap {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] (S : StarSubalgebra R B) (f : A →⋆ₐ[R] B) (x : A) :
x ∈ StarSubalgebra.comap f S ↔ f x ∈ S
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@[simp]
theorem StarSubalgebra.coe_comap {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] [Semiring B] [StarRing B] [Algebra R B] [StarModule R B] (S : StarSubalgebra R B) (f : A →⋆ₐ[R] B) :
↑(StarSubalgebra.comap f S) = ⇑f ⁻¹' ↑S
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def StarSubalgebra.centralizer (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (s : Set A) :
StarSubalgebra R A

The centralizer, or commutant, of the star-closure of a set as a star subalgebra.

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@[simp]
theorem StarSubalgebra.coe_centralizer (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (s : Set A) :
↑(StarSubalgebra.centralizer R s) = Set.centralizer (s ∪ star s)
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theorem StarSubalgebra.mem_centralizer_iff (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] {s : Set A} {z : A} :
z ∈ StarSubalgebra.centralizer R s ↔ ∀ g ∈ s, g * z = z * g ∧ star g * z = z * star g
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theorem StarSubalgebra.centralizer_le (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [StarRing A] [Algebra R A] [StarModule R A] (s : Set A) (t : Set A) (h : s ⊆ t) :
StarSubalgebra.centralizer R t ≤ StarSubalgebra.centralizer R s

The star closure of a subalgebra #

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instance Subalgebra.involutiveStar {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
InvolutiveStar (Subalgebra R A)

The pointwise star of a subalgebra is a subalgebra.

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@[simp]
theorem Subalgebra.mem_star_iff {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Subalgebra R A) (x : A) :
x ∈ star S ↔ star x ∈ S
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theorem Subalgebra.star_mem_star_iff {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Subalgebra R A) (x : A) :
star x ∈ star S ↔ x ∈ S
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@[simp]
theorem Subalgebra.coe_star {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Subalgebra R A) :
↑(star S) = star ↑S
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theorem Subalgebra.star_mono {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
Monotone star
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theorem Subalgebra.star_adjoin_comm (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (s : Set A) :
star (Algebra.adjoin R s) = Algebra.adjoin R (star s)

The star operation on Subalgebra commutes with Algebra.adjoin.

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@[simp]
theorem Subalgebra.starClosure_carrier {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Subalgebra R A) :
↑(Subalgebra.starClosure S) = ⋂ (t : Subsemiring A), ⋂ (_ : Set.range ⇑(algebraMap R A) ⊆ ↑t ∧ ↑S ⊆ ↑t ∧ star ↑S ⊆ ↑t), ↑t
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def Subalgebra.starClosure {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Subalgebra R A) :
StarSubalgebra R A

The StarSubalgebra obtained from S : Subalgebra R A by taking the smallest subalgebra containing both S and star S.

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theorem Subalgebra.starClosure_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Subalgebra R A) :
(Subalgebra.starClosure S).toSubalgebra = S ⊔ star S
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theorem Subalgebra.starClosure_le {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S₁ : Subalgebra R A} {S₂ : StarSubalgebra R A} (h : S₁ ≤ S₂.toSubalgebra) :
Subalgebra.starClosure S₁ ≤ S₂
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theorem Subalgebra.starClosure_le_iff {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S₁ : Subalgebra R A} {S₂ : StarSubalgebra R A} :
Subalgebra.starClosure S₁ ≤ S₂ ↔ S₁ ≤ S₂.toSubalgebra

The star subalgebra generated by a set #

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@[simp]
theorem StarSubalgebra.adjoin_carrier (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (s : Set A) :
↑(StarSubalgebra.adjoin R s) = ⋂ (t : Subsemiring A), ⋂ (_ : Set.range ⇑(algebraMap R A) ⊆ ↑t ∧ s ⊆ ↑t ∧ star s ⊆ ↑t), ↑t
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def StarSubalgebra.adjoin (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (s : Set A) :
StarSubalgebra R A

The minimal star subalgebra that contains s.

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theorem StarSubalgebra.adjoin_eq_starClosure_adjoin (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (s : Set A) :
StarSubalgebra.adjoin R s = Subalgebra.starClosure (Algebra.adjoin R s)
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theorem StarSubalgebra.adjoin_toSubalgebra (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (s : Set A) :
(StarSubalgebra.adjoin R s).toSubalgebra = Algebra.adjoin R (s ∪ star s)
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theorem StarSubalgebra.subset_adjoin (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (s : Set A) :
s ⊆ ↑(StarSubalgebra.adjoin R s)
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theorem StarSubalgebra.star_subset_adjoin (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (s : Set A) :
star s ⊆ ↑(StarSubalgebra.adjoin R s)
source
theorem StarSubalgebra.self_mem_adjoin_singleton (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (x : A) :
x ∈ StarSubalgebra.adjoin R {x}
source
theorem StarSubalgebra.star_self_mem_adjoin_singleton (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (x : A) :
star x ∈ StarSubalgebra.adjoin R {x}
source
theorem StarSubalgebra.gc {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
GaloisConnection (StarSubalgebra.adjoin R) SetLike.coe
source
def StarSubalgebra.gi {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
GaloisInsertion (StarSubalgebra.adjoin R) SetLike.coe

Galois insertion between adjoin and coe.

Equations
  • One or more equations did not get rendered due to their size.
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theorem StarSubalgebra.adjoin_le {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} {s : Set A} (hs : s ⊆ ↑S) :
StarSubalgebra.adjoin R s ≤ S
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theorem StarSubalgebra.adjoin_le_iff {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} {s : Set A} :
StarSubalgebra.adjoin R s ≤ S ↔ s ⊆ ↑S
source
theorem Subalgebra.starClosure_eq_adjoin {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Subalgebra R A) :
Subalgebra.starClosure S = StarSubalgebra.adjoin R ↑S
source
theorem StarSubalgebra.adjoin_induction {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {s : Set A} {p : A → Prop} {a : A} (h : a ∈ StarSubalgebra.adjoin R s) (mem : ∀ x ∈ s, p x) (algebraMap : ∀ (r : R), p ((_root_.algebraMap R A) r)) (add : ∀ (x y : A), p x → p y → p (x + y)) (mul : ∀ (x y : A), p x → p y → p (x * y)) (star : ∀ (x : A), p x → p (Star.star x)) :
p a

If some predicate holds for all x ∈ (s : Set A) and this predicate is closed under the algebraMap, addition, multiplication and star operations, then it holds for a ∈ adjoin R s.

source
theorem StarSubalgebra.adjoin_induction₂ {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {s : Set A} {p : A → A → Prop} {a : A} {b : A} (ha : a ∈ StarSubalgebra.adjoin R s) (hb : b ∈ StarSubalgebra.adjoin R s) (Hs : ∀ x ∈ s, ∀ y ∈ s, p x y) (Halg : ∀ (r₁ r₂ : R), p ((algebraMap R A) r₁) ((algebraMap R A) r₂)) (Halg_left : ∀ (r : R), ∀ x ∈ s, p ((algebraMap R A) r) x) (Halg_right : ∀ (r : R), ∀ x ∈ s, p x ((algebraMap R A) r)) (Hadd_left : ∀ (x₁ x₂ y : A), p x₁ y → p x₂ y → p (x₁ + x₂) y) (Hadd_right : ∀ (x y₁ y₂ : A), p x y₁ → p x y₂ → p x (y₁ + y₂)) (Hmul_left : ∀ (x₁ x₂ y : A), p x₁ y → p x₂ y → p (x₁ * x₂) y) (Hmul_right : ∀ (x y₁ y₂ : A), p x y₁ → p x y₂ → p x (y₁ * y₂)) (Hstar : ∀ (x y : A), p x y → p (star x) (star y)) (Hstar_left : ∀ (x y : A), p x y → p (star x) y) (Hstar_right : ∀ (x y : A), p x y → p x (star y)) :
p a b
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theorem StarSubalgebra.adjoin_induction' {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {s : Set A} {p : ↥(StarSubalgebra.adjoin R s) → Prop} (a : ↥(StarSubalgebra.adjoin R s)) (mem : ∀ (x : A) (h : x ∈ s), p { val := x, property := ⋯ }) (algebraMap : ∀ (r : R), p ((_root_.algebraMap R ↥(StarSubalgebra.adjoin R s)) r)) (add : ∀ (x y : ↥(StarSubalgebra.adjoin R s)), p x → p y → p (x + y)) (mul : ∀ (x y : ↥(StarSubalgebra.adjoin R s)), p x → p y → p (x * y)) (star : ∀ (x : ↥(StarSubalgebra.adjoin R s)), p x → p (Star.star x)) :
p a

The difference with StarSubalgebra.adjoin_induction is that this acts on the subtype.

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@[reducible]
def StarSubalgebra.adjoinCommSemiringOfComm (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {s : Set A} (hcomm : ∀ a ∈ s, ∀ b ∈ s, a * b = b * a) (hcomm_star : ∀ a ∈ s, ∀ b ∈ s, a * star b = star b * a) :
CommSemiring ↥(StarSubalgebra.adjoin R s)

If all elements of s : Set A commute pairwise and also commute pairwise with elements of star s, then StarSubalgebra.adjoin R s is commutative. See note [reducible non-instances].

Equations
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@[reducible]
def StarSubalgebra.adjoinCommRingOfComm (R : Type u) {A : Type v} [CommRing R] [StarRing R] [Ring A] [Algebra R A] [StarRing A] [StarModule R A] {s : Set A} (hcomm : ∀ a ∈ s, ∀ b ∈ s, a * b = b * a) (hcomm_star : ∀ a ∈ s, ∀ b ∈ s, a * star b = star b * a) :
CommRing ↥(StarSubalgebra.adjoin R s)

If all elements of s : Set A commute pairwise and also commute pairwise with elements of star s, then StarSubalgebra.adjoin R s is commutative. See note [reducible non-instances].

Equations
  • One or more equations did not get rendered due to their size.
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instance StarSubalgebra.adjoinCommSemiringOfIsStarNormal (R : Type u_2) {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (x : A) [IsStarNormal x] :
CommSemiring ↥(StarSubalgebra.adjoin R {x})

The star subalgebra StarSubalgebra.adjoin R {x} generated by a single x : A is commutative if x is normal.

Equations
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instance StarSubalgebra.adjoinCommRingOfIsStarNormal (R : Type u) {A : Type v} [CommRing R] [StarRing R] [Ring A] [Algebra R A] [StarRing A] [StarModule R A] (x : A) [IsStarNormal x] :
CommRing ↥(StarSubalgebra.adjoin R {x})

The star subalgebra StarSubalgebra.adjoin R {x} generated by a single x : A is commutative if x is normal.

Equations

Complete lattice structure #

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instance StarSubalgebra.completeLattice {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
CompleteLattice (StarSubalgebra R A)
Equations
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instance StarSubalgebra.inhabited {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
Inhabited (StarSubalgebra R A)
Equations
  • StarSubalgebra.inhabited = { default := ⊤ }
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@[simp]
theorem StarSubalgebra.coe_top {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
↑⊤ = Set.univ
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@[simp]
theorem StarSubalgebra.mem_top {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {x : A} :
x ∈ ⊤
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@[simp]
theorem StarSubalgebra.top_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
⊤.toSubalgebra = ⊤
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@[simp]
theorem StarSubalgebra.toSubalgebra_eq_top {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} :
S.toSubalgebra = ⊤ ↔ S = ⊤
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theorem StarSubalgebra.mem_sup_left {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} {T : StarSubalgebra R A} {x : A} :
x ∈ S → x ∈ S ⊔ T
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theorem StarSubalgebra.mem_sup_right {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} {T : StarSubalgebra R A} {x : A} :
x ∈ T → x ∈ S ⊔ T
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theorem StarSubalgebra.mul_mem_sup {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} {T : StarSubalgebra R A} {x : A} {y : A} (hx : x ∈ S) (hy : y ∈ T) :
x * y ∈ S ⊔ T
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theorem StarSubalgebra.map_sup {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (S : StarSubalgebra R A) (T : StarSubalgebra R A) :
StarSubalgebra.map f (S ⊔ T) = StarSubalgebra.map f S ⊔ StarSubalgebra.map f T
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@[simp]
theorem StarSubalgebra.coe_inf {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : StarSubalgebra R A) (T : StarSubalgebra R A) :
↑(S ⊓ T) = ↑S ∩ ↑T
source
@[simp]
theorem StarSubalgebra.mem_inf {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} {T : StarSubalgebra R A} {x : A} :
x ∈ S ⊓ T ↔ x ∈ S ∧ x ∈ T
source
@[simp]
theorem StarSubalgebra.inf_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : StarSubalgebra R A) (T : StarSubalgebra R A) :
(S ⊓ T).toSubalgebra = S.toSubalgebra ⊓ T.toSubalgebra
source
@[simp]
theorem StarSubalgebra.coe_sInf {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Set (StarSubalgebra R A)) :
↑(sInf S) = ⋂ s ∈ S, ↑s
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theorem StarSubalgebra.mem_sInf {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : Set (StarSubalgebra R A)} {x : A} :
x ∈ sInf S ↔ ∀ p ∈ S, x ∈ p
source
@[simp]
theorem StarSubalgebra.sInf_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] (S : Set (StarSubalgebra R A)) :
(sInf S).toSubalgebra = sInf (StarSubalgebra.toSubalgebra '' S)
source
@[simp]
theorem StarSubalgebra.coe_iInf {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {ι : Sort u_5} {S : ι → StarSubalgebra R A} :
↑(⨅ (i : ι), S i) = ⋂ (i : ι), ↑(S i)
source
theorem StarSubalgebra.mem_iInf {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {ι : Sort u_5} {S : ι → StarSubalgebra R A} {x : A} :
x ∈ ⨅ (i : ι), S i ↔ ∀ (i : ι), x ∈ S i
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@[simp]
theorem StarSubalgebra.iInf_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {ι : Sort u_5} (S : ι → StarSubalgebra R A) :
(⨅ (i : ι), S i).toSubalgebra = ⨅ (i : ι), (S i).toSubalgebra
source
theorem StarSubalgebra.bot_toSubalgebra {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
⊥.toSubalgebra = ⊥
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theorem StarSubalgebra.mem_bot {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {x : A} :
x ∈ ⊥ ↔ x ∈ Set.range ⇑(algebraMap R A)
source
@[simp]
theorem StarSubalgebra.coe_bot {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] :
↑⊥ = Set.range ⇑(algebraMap R A)
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theorem StarSubalgebra.eq_top_iff {R : Type u_2} {A : Type u_3} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] {S : StarSubalgebra R A} :
S = ⊤ ↔ ∀ (x : A), x ∈ S
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def StarAlgHom.equalizer {F : Type u_1} {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] [FunLike F A B] [AlgHomClass F R A B] [StarAlgHomClass F R A B] (f : F) (g : F) :
StarSubalgebra R A

The equalizer of two star R-algebra homomorphisms.

Equations
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@[simp]
theorem StarAlgHom.mem_equalizer {F : Type u_1} {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] [FunLike F A B] [AlgHomClass F R A B] [StarAlgHomClass F R A B] (f : F) (g : F) (x : A) :
x ∈ StarAlgHom.equalizer f g ↔ f x = g x
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theorem StarAlgHom.adjoin_le_equalizer {F : Type u_1} {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] [FunLike F A B] [AlgHomClass F R A B] [StarAlgHomClass F R A B] (f : F) (g : F) {s : Set A} (h : Set.EqOn (⇑f) (⇑g) s) :
StarSubalgebra.adjoin R s ≤ StarAlgHom.equalizer f g
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theorem StarAlgHom.ext_of_adjoin_eq_top {F : Type u_1} {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] [FunLike F A B] [AlgHomClass F R A B] [StarAlgHomClass F R A B] {s : Set A} (h : StarSubalgebra.adjoin R s = ⊤) ⦃f : F⦄ ⦃g : F⦄ (hs : Set.EqOn (⇑f) (⇑g) s) :
f = g
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theorem StarAlgHom.map_adjoin {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (s : Set A) :
StarSubalgebra.map f (StarSubalgebra.adjoin R s) = StarSubalgebra.adjoin R (⇑f '' s)
source
theorem StarAlgHom.ext_adjoin {F : Type u_1} {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] {s : Set A} [FunLike F (↥(StarSubalgebra.adjoin R s)) B] [AlgHomClass F R (↥(StarSubalgebra.adjoin R s)) B] [StarAlgHomClass F R (↥(StarSubalgebra.adjoin R s)) B] {f : F} {g : F} (h : ∀ (x : ↥(StarSubalgebra.adjoin R s)), ↑x ∈ s → f x = g x) :
f = g
source
theorem StarAlgHom.ext_adjoin_singleton {F : Type u_1} {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] {a : A} [FunLike F (↥(StarSubalgebra.adjoin R {a})) B] [AlgHomClass F R (↥(StarSubalgebra.adjoin R {a})) B] [StarAlgHomClass F R (↥(StarSubalgebra.adjoin R {a})) B] {f : F} {g : F} (h : f { val := a, property := ⋯ } = g { val := a, property := ⋯ }) :
f = g
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def StarAlgHom.range {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (φ : A →⋆ₐ[R] B) :
StarSubalgebra R B

Range of a StarAlgHom as a star subalgebra.

Equations
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theorem StarAlgHom.range_eq_map_top {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [StarModule R A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (φ : A →⋆ₐ[R] B) :
StarAlgHom.range φ = StarSubalgebra.map φ ⊤
source
def StarAlgHom.codRestrict {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (S : StarSubalgebra R B) (hf : ∀ (x : A), f x ∈ S) :
A →⋆ₐ[R] ↥S

Restriction of the codomain of a StarAlgHom to a star subalgebra containing the range.

Equations
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@[simp]
theorem StarAlgHom.coe_codRestrict {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (S : StarSubalgebra R B) (hf : ∀ (x : A), f x ∈ S) (x : A) :
↑((StarAlgHom.codRestrict f S hf) x) = f x
source
@[simp]
theorem StarAlgHom.subtype_comp_codRestrict {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (S : StarSubalgebra R B) (hf : ∀ (x : A), f x ∈ S) :
StarAlgHom.comp (StarSubalgebra.subtype S) (StarAlgHom.codRestrict f S hf) = f
source
theorem StarAlgHom.injective_codRestrict {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (S : StarSubalgebra R B) (hf : ∀ (x : A), f x ∈ S) :
Function.Injective ⇑(StarAlgHom.codRestrict f S hf) ↔ Function.Injective ⇑f
source
def StarAlgHom.rangeRestrict {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) :
A →⋆ₐ[R] ↥(StarAlgHom.range f)

Restriction of the codomain of a StarAlgHom to its range.

Equations
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@[simp]
theorem StarAlgEquiv.ofInjective_symm_apply {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (hf : Function.Injective ⇑f) :
∀ (a : ↥(AlgHom.range ↑f)), (StarAlgEquiv.symm (StarAlgEquiv.ofInjective f hf)) a = (AlgEquiv.ofInjective (↑f) hf).invFun a
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@[simp]
theorem StarAlgEquiv.ofInjective_apply {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (hf : Function.Injective ⇑f) (a : A) :
(StarAlgEquiv.ofInjective f hf) a = (StarAlgHom.rangeRestrict f) a
source
noncomputable def StarAlgEquiv.ofInjective {R : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [StarRing R] [Semiring A] [Algebra R A] [StarRing A] [Semiring B] [Algebra R B] [StarRing B] [StarModule R B] (f : A →⋆ₐ[R] B) (hf : Function.Injective ⇑f) :
A ≃⋆ₐ[R] ↥(StarAlgHom.range f)

The StarAlgEquiv onto the range corresponding to an injective StarAlgHom.

Equations
  • One or more equations did not get rendered due to their size.
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@[simp]
theorem StarAlgHom.restrictScalars_apply (R : Type u_1) {S : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [CommSemiring S] [Semiring A] [Semiring B] [Algebra R S] [Algebra S A] [Algebra S B] [Algebra R A] [Algebra R B] [IsScalarTower R S A] [IsScalarTower R S B] [Star A] [Star B] (f : A →⋆ₐ[S] B) :
∀ (a : A), (StarAlgHom.restrictScalars R f) a = f a
source
def StarAlgHom.restrictScalars (R : Type u_1) {S : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [CommSemiring S] [Semiring A] [Semiring B] [Algebra R S] [Algebra S A] [Algebra S B] [Algebra R A] [Algebra R B] [IsScalarTower R S A] [IsScalarTower R S B] [Star A] [Star B] (f : A →⋆ₐ[S] B) :
A →⋆ₐ[R] B
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theorem StarAlgHom.restrictScalars_injective (R : Type u_1) {S : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [CommSemiring S] [Semiring A] [Semiring B] [Algebra R S] [Algebra S A] [Algebra S B] [Algebra R A] [Algebra R B] [IsScalarTower R S A] [IsScalarTower R S B] [Star A] [Star B] :
Function.Injective (StarAlgHom.restrictScalars R)
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@[simp]
theorem StarAlgEquiv.restrictScalars_symm_apply (R : Type u_1) {S : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [CommSemiring S] [Semiring A] [Semiring B] [Algebra R S] [Algebra S A] [Algebra S B] [Algebra R A] [Algebra R B] [IsScalarTower R S A] [IsScalarTower R S B] [Star A] [Star B] (f : A ≃⋆ₐ[S] B) :
∀ (a : B), (StarAlgEquiv.symm (StarAlgEquiv.restrictScalars R f)) a = f.invFun a
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@[simp]
theorem StarAlgEquiv.restrictScalars_apply (R : Type u_1) {S : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [CommSemiring S] [Semiring A] [Semiring B] [Algebra R S] [Algebra S A] [Algebra S B] [Algebra R A] [Algebra R B] [IsScalarTower R S A] [IsScalarTower R S B] [Star A] [Star B] (f : A ≃⋆ₐ[S] B) (a : A) :
(StarAlgEquiv.restrictScalars R f) a = f a
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def StarAlgEquiv.restrictScalars (R : Type u_1) {S : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [CommSemiring S] [Semiring A] [Semiring B] [Algebra R S] [Algebra S A] [Algebra S B] [Algebra R A] [Algebra R B] [IsScalarTower R S A] [IsScalarTower R S B] [Star A] [Star B] (f : A ≃⋆ₐ[S] B) :
A ≃⋆ₐ[R] B
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theorem StarAlgEquiv.restrictScalars_injective (R : Type u_1) {S : Type u_2} {A : Type u_3} {B : Type u_4} [CommSemiring R] [CommSemiring S] [Semiring A] [Semiring B] [Algebra R S] [Algebra S A] [Algebra S B] [Algebra R A] [Algebra R B] [IsScalarTower R S A] [IsScalarTower R S B] [Star A] [Star B] :
Function.Injective (StarAlgEquiv.restrictScalars R)