Documentation

Mathlib.Algebra.Star.NonUnitalSubalgebra

Non-unital Star Subalgebras #

In this file we define NonUnitalStarSubalgebras and the usual operations on them (map, comap).

TODO #

instance StarMemClass.instInvolutiveStar {S : Type u_1} {R : Type u_2} [InvolutiveStar R] [SetLike S R] [StarMemClass S R] (s : S) :
InvolutiveStar { x : R // x s }

If a type carries an involutive star, then any star-closed subset does too.

Equations
instance StarMemClass.instStarMul {S : Type u_1} {R : Type u_2} [Mul R] [StarMul R] [SetLike S R] [MulMemClass S R] [StarMemClass S R] (s : S) :
StarMul { x : R // x s }

In a star magma (i.e., a multiplication with an antimultiplicative involutive star operation), any star-closed subset which is also closed under multiplication is itself a star magma.

Equations
instance StarMemClass.instStarAddMonoid {S : Type u_1} {R : Type u_2} [AddMonoid R] [StarAddMonoid R] [SetLike S R] [AddSubmonoidClass S R] [StarMemClass S R] (s : S) :
StarAddMonoid { x : R // x s }

In a StarAddMonoid (i.e., an additive monoid with an additive involutive star operation), any star-closed subset which is also closed under addition and contains zero is itself a StarAddMonoid.

Equations
instance StarMemClass.instStarRing {S : Type u_1} {R : Type u_2} [NonUnitalNonAssocSemiring R] [StarRing R] [SetLike S R] [NonUnitalSubsemiringClass S R] [StarMemClass S R] (s : S) :
StarRing { x : R // x s }

In a star ring (i.e., a non-unital, non-associative, semiring with an additive, antimultiplicative, involutive star operation), a star-closed non-unital subsemiring is itself a star ring.

Equations
instance StarMemClass.instStarModule {S : Type u_1} (R : Type u_2) {M : Type u_3} [Star R] [Star M] [SMul R M] [StarModule R M] [SetLike S M] [SMulMemClass S R M] [StarMemClass S M] (s : S) :
StarModule R { x : M // x s }

In a star R-module (i.e., star (r • m) = (star r) • m) any star-closed subset which is also closed under the scalar action by R is itself a star R-module.

Equations
  • =
def NonUnitalStarSubalgebraClass.subtype {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Star A] [Module R A] {S : Type w''} [SetLike S A] [NonUnitalSubsemiringClass S A] [hSR : SMulMemClass S R A] [StarMemClass S A] (s : S) :
{ x : A // x s } →⋆ₙₐ[R] A

Embedding of a non-unital star subalgebra into the non-unital star algebra.

Equations
@[simp]

A non-unital star subalgebra is a non-unital subalgebra which is closed under the star operation.

  • carrier : Set A
  • add_mem' : ∀ {a b : A}, a self.carrierb self.carriera + b self.carrier
  • zero_mem' : 0 self.carrier
  • mul_mem' : ∀ {a b : A}, a self.carrierb self.carriera * b self.carrier
  • smul_mem' : ∀ (c : R) {x : A}, x self.carrierc x self.carrier
  • star_mem' : ∀ {a : A}, a self.carrierstar a self.carrier

    The carrier of a NonUnitalStarSubalgebra is closed under the star operation.

Instances For
theorem NonUnitalStarSubalgebra.star_mem' {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (self : NonUnitalStarSubalgebra R A) {a : A} (_ha : a self.carrier) :
star a self.carrier

The carrier of a NonUnitalStarSubalgebra is closed under the star operation.

Equations
  • NonUnitalStarSubalgebra.instSetLike = { coe := fun {s : NonUnitalStarSubalgebra R A} => s.carrier, coe_injective' := }
theorem NonUnitalStarSubalgebra.mem_carrier {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] {s : NonUnitalStarSubalgebra R A} {x : A} :
x s.carrier x s
theorem NonUnitalStarSubalgebra.ext_iff {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} :
S = T ∀ (x : A), x S x T
theorem NonUnitalStarSubalgebra.ext {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} (h : ∀ (x : A), x S x T) :
S = T
@[simp]
theorem NonUnitalStarSubalgebra.mem_toNonUnitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} {x : A} :
x S.toNonUnitalSubalgebra x S
@[simp]
theorem NonUnitalStarSubalgebra.coe_toNonUnitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) :
S.toNonUnitalSubalgebra = S
theorem NonUnitalStarSubalgebra.toNonUnitalSubalgebra_injective {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] :
Function.Injective NonUnitalStarSubalgebra.toNonUnitalSubalgebra
theorem NonUnitalStarSubalgebra.toNonUnitalSubalgebra_inj {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} {U : NonUnitalStarSubalgebra R A} :
S.toNonUnitalSubalgebra = U.toNonUnitalSubalgebra S = U
theorem NonUnitalStarSubalgebra.toNonUnitalSubalgebra_le_iff {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] {S₁ : NonUnitalStarSubalgebra R A} {S₂ : NonUnitalStarSubalgebra R A} :
S₁.toNonUnitalSubalgebra S₂.toNonUnitalSubalgebra S₁ S₂

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

Equations
  • S.copy s hs = { toNonUnitalSubalgebra := S.copy s hs, star_mem' := }
@[simp]
theorem NonUnitalStarSubalgebra.coe_copy {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) (s : Set A) (hs : s = S) :
(S.copy s hs) = s
theorem NonUnitalStarSubalgebra.copy_eq {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) (s : Set A) (hs : s = S) :
S.copy s hs = S

A non-unital star subalgebra over a ring is also a Subring.

Equations
  • S.toNonUnitalSubring = { toNonUnitalSubsemiring := S.toNonUnitalSubsemiring, neg_mem' := }
@[simp]
theorem NonUnitalStarSubalgebra.mem_toNonUnitalSubring {R : Type u} {A : Type v} [CommRing R] [NonUnitalRing A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} {x : A} :
x S.toNonUnitalSubring x S
@[simp]
theorem NonUnitalStarSubalgebra.coe_toNonUnitalSubring {R : Type u} {A : Type v} [CommRing R] [NonUnitalRing A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) :
S.toNonUnitalSubring = S
theorem NonUnitalStarSubalgebra.toNonUnitalSubring_injective {R : Type u} {A : Type v} [CommRing R] [NonUnitalRing A] [Module R A] [Star A] :
Function.Injective NonUnitalStarSubalgebra.toNonUnitalSubring
theorem NonUnitalStarSubalgebra.toNonUnitalSubring_inj {R : Type u} {A : Type v} [CommRing R] [NonUnitalRing A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} {U : NonUnitalStarSubalgebra R A} :
S.toNonUnitalSubring = U.toNonUnitalSubring S = U
Equations
  • S.instInhabited = { default := 0 }

NonUnitalStarSubalgebras inherit structure from their NonUnitalSubsemiringClass and NonUnitalSubringClass instances.

Equations
  • S.toNonUnitalSemiring = inferInstance
Equations
  • S.toNonUnitalCommSemiring = inferInstance
instance NonUnitalStarSubalgebra.toNonUnitalRing {R : Type u_1} {A : Type u_2} [CommRing R] [NonUnitalRing A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) :
NonUnitalRing { x : A // x S }
Equations
  • S.toNonUnitalRing = inferInstance
Equations
  • S.toNonUnitalCommRing = inferInstance

The forgetful map from NonUnitalStarSubalgebra to NonUnitalSubalgebra as an OrderEmbedding

Equations
  • NonUnitalStarSubalgebra.toNonUnitalSubalgebra' = { toFun := fun (S : NonUnitalStarSubalgebra R A) => S.toNonUnitalSubalgebra, inj' := , map_rel_iff' := }

NonUnitalStarSubalgebras inherit structure from their Submodule coercions.

instance NonUnitalStarSubalgebra.module' {R' : Type u'} {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) [Semiring R'] [SMul R' R] [Module R' A] [IsScalarTower R' R A] :
Module R' { x : A // x S }
Equations
instance NonUnitalStarSubalgebra.instModule {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) :
Module R { x : A // x S }
Equations
  • S.instModule = S.module'
instance NonUnitalStarSubalgebra.instIsScalarTower' {R' : Type u'} {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) [Semiring R'] [SMul R' R] [Module R' A] [IsScalarTower R' R A] :
IsScalarTower R' R { x : A // x S }
Equations
  • =
instance NonUnitalStarSubalgebra.instIsScalarTower {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) [IsScalarTower R A A] :
IsScalarTower R { x : A // x S } { x : A // x S }
Equations
  • =
instance NonUnitalStarSubalgebra.instSMulCommClass' {R' : Type u'} {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) [Semiring R'] [SMul R' R] [Module R' A] [IsScalarTower R' R A] [SMulCommClass R' R A] :
SMulCommClass R' R { x : A // x S }
Equations
  • =
instance NonUnitalStarSubalgebra.instSMulCommClass {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) [SMulCommClass R A A] :
SMulCommClass R { x : A // x S } { x : A // x S }
Equations
  • =
theorem NonUnitalStarSubalgebra.coe_add {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) (x : { x : A // x S }) (y : { x : A // x S }) :
(x + y) = x + y
theorem NonUnitalStarSubalgebra.coe_mul {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) (x : { x : A // x S }) (y : { x : A // x S }) :
(x * y) = x * y
theorem NonUnitalStarSubalgebra.coe_neg {R : Type u} {A : Type v} [CommRing R] [NonUnitalRing A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} (x : { x : A // x S }) :
(-x) = -x
theorem NonUnitalStarSubalgebra.coe_sub {R : Type u} {A : Type v} [CommRing R] [NonUnitalRing A] [Module R A] [Star A] {S : NonUnitalStarSubalgebra R A} (x : { x : A // x S }) (y : { x : A // x S }) :
(x - y) = x - y
@[simp]
theorem NonUnitalStarSubalgebra.coe_smul {R' : Type u'} {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) [Semiring R'] [SMul R' R] [Module R' A] [IsScalarTower R' R A] (r : R') (x : { x : A // x S }) :
(r x) = r x
theorem NonUnitalStarSubalgebra.coe_eq_zero {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) {x : { x : A // x S }} :
x = 0 x = 0

Transport a non-unital star subalgebra via a non-unital star algebra homomorphism.

Equations
@[simp]
theorem NonUnitalStarSubalgebra.mem_map {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] {S : NonUnitalStarSubalgebra R A} {f : F} {y : B} :
y NonUnitalStarSubalgebra.map f S xS, f x = y
theorem NonUnitalStarSubalgebra.map_toNonUnitalSubalgebra {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] {S : NonUnitalStarSubalgebra R A} {f : F} :
(NonUnitalStarSubalgebra.map f S).toNonUnitalSubalgebra = NonUnitalSubalgebra.map f S.toNonUnitalSubalgebra
@[simp]
theorem NonUnitalStarSubalgebra.coe_map {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (S : NonUnitalStarSubalgebra R A) (f : F) :
(NonUnitalStarSubalgebra.map f S) = f '' S

Preimage of a non-unital star subalgebra under a non-unital star algebra homomorphism.

Equations
@[simp]
theorem NonUnitalStarSubalgebra.mem_comap {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (S : NonUnitalStarSubalgebra R B) (f : F) (x : A) :
@[simp]
theorem NonUnitalStarSubalgebra.coe_comap {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (S : NonUnitalStarSubalgebra R B) (f : F) :
Equations
  • =

A non-unital subalgebra closed under star is a non-unital star subalgebra.

Equations
  • s.toNonUnitalStarSubalgebra h_star = { toNonUnitalSubalgebra := s, star_mem' := h_star }
@[simp]
theorem NonUnitalSubalgebra.mem_toNonUnitalStarSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] {s : NonUnitalSubalgebra R A} {h_star : xs, star x s} {x : A} :
x s.toNonUnitalStarSubalgebra h_star x s
@[simp]
theorem NonUnitalSubalgebra.coe_toNonUnitalStarSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] (s : NonUnitalSubalgebra R A) (h_star : xs, star x s) :
(s.toNonUnitalStarSubalgebra h_star) = s
@[simp]
theorem NonUnitalSubalgebra.toNonUnitalStarSubalgebra_toNonUnitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] (s : NonUnitalSubalgebra R A) (h_star : xs, star x s) :
(s.toNonUnitalStarSubalgebra h_star).toNonUnitalSubalgebra = s
@[simp]
theorem NonUnitalStarSubalgebra.toNonUnitalSubalgebra_toNonUnitalStarSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] (S : NonUnitalStarSubalgebra R A) :
S.toNonUnitalStarSubalgebra = S
def NonUnitalStarAlgHom.range {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (φ : F) :

Range of an NonUnitalAlgHom as a NonUnitalStarSubalgebra.

Equations
@[simp]
theorem NonUnitalStarAlgHom.mem_range {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (φ : F) {y : B} :
y NonUnitalStarAlgHom.range φ ∃ (x : A), φ x = y
theorem NonUnitalStarAlgHom.mem_range_self {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (φ : F) (x : A) :
@[simp]
theorem NonUnitalStarAlgHom.coe_range {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (φ : F) :
def NonUnitalStarAlgHom.codRestrict {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (f : F) (S : NonUnitalStarSubalgebra R B) (hf : ∀ (x : A), f x S) :
A →⋆ₙₐ[R] { x : B // x S }

Restrict the codomain of a non-unital star algebra homomorphism.

Equations
@[simp]
theorem NonUnitalStarAlgHom.subtype_comp_codRestrict {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (f : F) (S : NonUnitalStarSubalgebra R B) (hf : ∀ (x : A), f x S) :
@[simp]
theorem NonUnitalStarAlgHom.coe_codRestrict {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (f : F) (S : NonUnitalStarSubalgebra R B) (hf : ∀ (x : A), f x S) (x : A) :
@[reducible, inline]
abbrev NonUnitalStarAlgHom.rangeRestrict {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (f : F) :

Restrict the codomain of a non-unital star algebra homomorphism f to f.range.

This is the bundled version of Set.rangeFactorization.

Equations
def NonUnitalStarAlgHom.equalizer {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (ϕ : F) (ψ : F) :

The equalizer of two non-unital star R-algebra homomorphisms

Equations
@[simp]
theorem NonUnitalStarAlgHom.mem_equalizer {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalNonAssocSemiring A] [Module R A] [Star A] [NonUnitalNonAssocSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (φ : F) (ψ : F) (x : A) :
def StarAlgEquiv.ofLeftInverse' {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] [NonUnitalSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] {g : BA} {f : F} (h : Function.LeftInverse g f) :

Restrict a non-unital star algebra homomorphism with a left inverse to an algebra isomorphism to its range.

This is a computable alternative to StarAlgEquiv.ofInjective.

Equations
  • One or more equations did not get rendered due to their size.
@[simp]
theorem StarAlgEquiv.ofLeftInverse'_apply {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] [NonUnitalSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] {g : BA} {f : F} (h : Function.LeftInverse g f) (x : A) :
@[simp]
theorem StarAlgEquiv.ofLeftInverse'_symm_apply {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] [NonUnitalSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] {g : BA} {f : F} (h : Function.LeftInverse g f) (x : { x : B // x NonUnitalStarAlgHom.range f }) :
(StarAlgEquiv.ofLeftInverse' h).symm x = g x
noncomputable def StarAlgEquiv.ofInjective' {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] [NonUnitalSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (f : F) (hf : Function.Injective f) :

Restrict an injective non-unital star algebra homomorphism to a star algebra isomorphism

Equations
@[simp]
theorem StarAlgEquiv.ofInjective'_apply {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [Module R A] [Star A] [NonUnitalSemiring B] [Module R B] [Star B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] (f : F) (hf : Function.Injective f) (x : A) :
((StarAlgEquiv.ofInjective' f hf) x) = f x

The star closure of a subalgebra #

The pointwise star of a non-unital subalgebra is a non-unital subalgebra.

Equations
@[simp]
theorem NonUnitalSubalgebra.mem_star_iff {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarModule R A] (S : NonUnitalSubalgebra R A) (x : A) :
x star S star x S
@[simp]
theorem NonUnitalSubalgebra.coe_star {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarModule R A] (S : NonUnitalSubalgebra R A) :
(star S) = star S
@[simp]
theorem NonUnitalSubalgebra.starClosure_carrier {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarModule R A] [IsScalarTower R A A] [SMulCommClass R A A] (S : NonUnitalSubalgebra R A) :
S.starClosure = ⋂ (s : Submodule R A), ⋂ (_ : (NonUnitalSubsemiring.closure (S star S)) s), s

The NonUnitalStarSubalgebra obtained from S : NonUnitalSubalgebra R A by taking the smallest non-unital subalgebra containing both S and star S.

Equations
  • S.starClosure = { toNonUnitalSubalgebra := S star S, star_mem' := }
theorem NonUnitalSubalgebra.starClosure_le {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarModule R A] [IsScalarTower R A A] [SMulCommClass R A A] {S₁ : NonUnitalSubalgebra R A} {S₂ : NonUnitalStarSubalgebra R A} (h : S₁ S₂.toNonUnitalSubalgebra) :
S₁.starClosure S₂
theorem NonUnitalSubalgebra.starClosure_le_iff {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarModule R A] [IsScalarTower R A A] [SMulCommClass R A A] {S₁ : NonUnitalSubalgebra R A} {S₂ : NonUnitalStarSubalgebra R A} :
S₁.starClosure S₂ S₁ S₂.toNonUnitalSubalgebra
@[simp]
theorem NonUnitalSubalgebra.starClosure_toNonunitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarModule R A] [IsScalarTower R A A] [SMulCommClass R A A] {S : NonUnitalSubalgebra R A} :
S.starClosure.toNonUnitalSubalgebra = S star S
theorem NonUnitalSubalgebra.starClosure_mono {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarModule R A] [IsScalarTower R A A] [SMulCommClass R A A] :
Monotone NonUnitalSubalgebra.starClosure

The minimal non-unital subalgebra that includes s.

Equations
theorem NonUnitalStarAlgebra.adjoin_induction' (R : Type u) {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {s : Set A} {p : (x : A) → x NonUnitalStarAlgebra.adjoin R sProp} {a : A} (ha : a NonUnitalStarAlgebra.adjoin R s) (mem : ∀ (x : A) (hx : x s), p x ) (add : ∀ (x : A) (hx : x NonUnitalStarAlgebra.adjoin R s) (y : A) (hy : y NonUnitalStarAlgebra.adjoin R s), p x hxp y hyp (x + y) ) (zero : p 0 ) (mul : ∀ (x : A) (hx : x NonUnitalStarAlgebra.adjoin R s) (y : A) (hy : y NonUnitalStarAlgebra.adjoin R s), p x hxp y hyp (x * y) ) (smul : ∀ (r : R) (x : A) (hx : x NonUnitalStarAlgebra.adjoin R s), p x hxp (r x) ) (star : ∀ (x : A) (hx : x NonUnitalStarAlgebra.adjoin R s), p x hxp (Star.star x) ) :
p a ha

Galois insertion between adjoin and Subtype.val.

Equations
  • One or more equations did not get rendered due to their size.
@[simp]
Equations
  • NonUnitalStarAlgebra.instCompleteLatticeNonUnitalStarSubalgebra = NonUnitalStarAlgebra.gi.liftCompleteLattice
@[simp]
theorem NonUnitalStarAlgebra.coe_top {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] :
= Set.univ
@[simp]
theorem NonUnitalStarAlgebra.mem_top {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {x : A} :
@[simp]
theorem NonUnitalStarAlgebra.top_toNonUnitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] :
.toNonUnitalSubalgebra =
@[simp]
theorem NonUnitalStarAlgebra.toNonUnitalSubalgebra_eq_top {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} :
S.toNonUnitalSubalgebra = S =
theorem NonUnitalStarAlgebra.mem_sup_left {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} {x : A} :
x Sx S T
theorem NonUnitalStarAlgebra.mul_mem_sup {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} {x : A} {y : A} (hx : x S) (hy : y T) :
x * y S T
@[simp]
theorem NonUnitalStarAlgebra.coe_inf {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] (S : NonUnitalStarSubalgebra R A) (T : NonUnitalStarSubalgebra R A) :
(S T) = S T
@[simp]
theorem NonUnitalStarAlgebra.mem_inf {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} {x : A} :
x S T x S x T
@[simp]
theorem NonUnitalStarAlgebra.inf_toNonUnitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] (S : NonUnitalStarSubalgebra R A) (T : NonUnitalStarSubalgebra R A) :
(S T).toNonUnitalSubalgebra = S.toNonUnitalSubalgebra T.toNonUnitalSubalgebra
@[simp]
theorem NonUnitalStarAlgebra.coe_sInf {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] (S : Set (NonUnitalStarSubalgebra R A)) :
(sInf S) = sS, s
theorem NonUnitalStarAlgebra.mem_sInf {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : Set (NonUnitalStarSubalgebra R A)} {x : A} :
x sInf S pS, x p
@[simp]
theorem NonUnitalStarAlgebra.sInf_toNonUnitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] (S : Set (NonUnitalStarSubalgebra R A)) :
(sInf S).toNonUnitalSubalgebra = sInf (NonUnitalStarSubalgebra.toNonUnitalSubalgebra '' S)
@[simp]
theorem NonUnitalStarAlgebra.coe_iInf {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {ι : Sort u_1} {S : ιNonUnitalStarSubalgebra R A} :
(⨅ (i : ι), S i) = ⋂ (i : ι), (S i)
theorem NonUnitalStarAlgebra.mem_iInf {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {ι : Sort u_1} {S : ιNonUnitalStarSubalgebra R A} {x : A} :
x ⨅ (i : ι), S i ∀ (i : ι), x S i
@[simp]
theorem NonUnitalStarAlgebra.iInf_toNonUnitalSubalgebra {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {ι : Sort u_1} (S : ιNonUnitalStarSubalgebra R A) :
(⨅ (i : ι), S i).toNonUnitalSubalgebra = ⨅ (i : ι), (S i).toNonUnitalSubalgebra
Equations
  • NonUnitalStarAlgebra.instInhabitedNonUnitalStarSubalgebra = { default := }
theorem NonUnitalStarAlgebra.mem_bot {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {x : A} :
x x = 0
theorem NonUnitalStarAlgebra.toNonUnitalSubalgebra_bot {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] :
.toNonUnitalSubalgebra =
@[simp]
theorem NonUnitalStarAlgebra.coe_bot {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] :
= {0}
theorem NonUnitalStarAlgebra.eq_top_iff {R : Type u} {A : Type v} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} :
S = ∀ (x : A), x S
@[simp]
theorem NonUnitalStarAlgebra.map_bot {F : Type v'} {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [StarRing R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] [FunLike F A B] [NonUnitalAlgHomClass F R A B] [StarHomClass F A B] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [IsScalarTower R B B] [SMulCommClass R B B] [StarModule R B] (f : F) :
@[simp]
def NonUnitalStarSubalgebra.inclusion {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} (h : S T) :
{ x : A // x S } →⋆ₙₐ[R] { x : A // x T }

The map S → T when S is a non-unital star subalgebra contained in the non-unital star algebra T.

This is the non-unital star subalgebra version of Submodule.inclusion, or NonUnitalSubalgebra.inclusion

Equations
@[simp]
theorem NonUnitalStarSubalgebra.inclusion_mk {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} (h : S T) (x : A) (hx : x S) :
(NonUnitalStarSubalgebra.inclusion h) x, hx = x,
theorem NonUnitalStarSubalgebra.inclusion_right {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} (h : S T) (x : { x : A // x T }) (m : x S) :
@[simp]
theorem NonUnitalStarSubalgebra.val_inclusion {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} (h : S T) (s : { x : A // x S }) :

The product of two non-unital star subalgebras is a non-unital star subalgebra.

Equations
  • S.prod S₁ = { carrier := S ×ˢ S₁, add_mem' := , zero_mem' := , mul_mem' := , smul_mem' := , star_mem' := }
@[simp]
theorem NonUnitalStarSubalgebra.coe_prod {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] (S : NonUnitalStarSubalgebra R A) (S₁ : NonUnitalStarSubalgebra R B) :
(S.prod S₁) = S ×ˢ S₁
theorem NonUnitalStarSubalgebra.prod_toNonUnitalSubalgebra {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] (S : NonUnitalStarSubalgebra R A) (S₁ : NonUnitalStarSubalgebra R B) :
(S.prod S₁).toNonUnitalSubalgebra = S.prod S₁.toNonUnitalSubalgebra
@[simp]
theorem NonUnitalStarSubalgebra.mem_prod {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] {S : NonUnitalStarSubalgebra R A} {S₁ : NonUnitalStarSubalgebra R B} {x : A × B} :
x S.prod S₁ x.1 S x.2 S₁
@[simp]
theorem NonUnitalStarSubalgebra.prod_top {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [IsScalarTower R B B] [SMulCommClass R B B] [StarModule R B] :
.prod =
theorem NonUnitalStarSubalgebra.prod_mono {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [IsScalarTower R B B] [SMulCommClass R B B] [StarModule R B] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} {S₁ : NonUnitalStarSubalgebra R B} {T₁ : NonUnitalStarSubalgebra R B} :
S TS₁ T₁S.prod S₁ T.prod T₁
@[simp]
theorem NonUnitalStarSubalgebra.prod_inf_prod {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [IsScalarTower R B B] [SMulCommClass R B B] [StarModule R B] {S : NonUnitalStarSubalgebra R A} {T : NonUnitalStarSubalgebra R A} {S₁ : NonUnitalStarSubalgebra R B} {T₁ : NonUnitalStarSubalgebra R B} :
S.prod S₁ T.prod T₁ = (S T).prod (S₁ T₁)
theorem NonUnitalStarSubalgebra.coe_iSup_of_directed {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] {ι : Type u_1} [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [Nonempty ι] {S : ιNonUnitalStarSubalgebra R A} (dir : Directed (fun (x1 x2 : NonUnitalStarSubalgebra R A) => x1 x2) S) :
(iSup S) = ⋃ (i : ι), (S i)
noncomputable def NonUnitalStarSubalgebra.iSupLift {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] {ι : Type u_1} [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [Nonempty ι] (K : ιNonUnitalStarSubalgebra R A) (dir : Directed (fun (x1 x2 : NonUnitalStarSubalgebra R A) => x1 x2) K) (f : (i : ι) → { x : A // x K i } →⋆ₙₐ[R] B) (hf : ∀ (i j : ι) (h : K i K j), f i = (f j).comp (NonUnitalStarSubalgebra.inclusion h)) (T : NonUnitalStarSubalgebra R A) (hT : T = iSup K) :
{ x : A // x T } →⋆ₙₐ[R] B

Define a non-unital star algebra homomorphism on a directed supremum of non-unital star subalgebras by defining it on each non-unital star subalgebra, and proving that it agrees on the intersection of non-unital star subalgebras.

Equations
  • One or more equations did not get rendered due to their size.
@[simp]
theorem NonUnitalStarSubalgebra.iSupLift_inclusion {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] {ι : Type u_1} [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [Nonempty ι] {K : ιNonUnitalStarSubalgebra R A} {dir : Directed (fun (x1 x2 : NonUnitalStarSubalgebra R A) => x1 x2) K} {f : (i : ι) → { x : A // x K i } →⋆ₙₐ[R] B} {hf : ∀ (i j : ι) (h : K i K j), f i = (f j).comp (NonUnitalStarSubalgebra.inclusion h)} {T : NonUnitalStarSubalgebra R A} {hT : T = iSup K} {i : ι} (x : { x : A // x K i }) (h : K i T) :
@[simp]
theorem NonUnitalStarSubalgebra.iSupLift_comp_inclusion {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] {ι : Type u_1} [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [Nonempty ι] {K : ιNonUnitalStarSubalgebra R A} {dir : Directed (fun (x1 x2 : NonUnitalStarSubalgebra R A) => x1 x2) K} {f : (i : ι) → { x : A // x K i } →⋆ₙₐ[R] B} {hf : ∀ (i j : ι) (h : K i K j), f i = (f j).comp (NonUnitalStarSubalgebra.inclusion h)} {T : NonUnitalStarSubalgebra R A} {hT : T = iSup K} {i : ι} (h : K i T) :
@[simp]
theorem NonUnitalStarSubalgebra.iSupLift_mk {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] {ι : Type u_1} [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [Nonempty ι] {K : ιNonUnitalStarSubalgebra R A} {dir : Directed (fun (x1 x2 : NonUnitalStarSubalgebra R A) => x1 x2) K} {f : (i : ι) → { x : A // x K i } →⋆ₙₐ[R] B} {hf : ∀ (i j : ι) (h : K i K j), f i = (f j).comp (NonUnitalStarSubalgebra.inclusion h)} {T : NonUnitalStarSubalgebra R A} {hT : T = iSup K} {i : ι} (x : { x : A // x K i }) (hx : x T) :
(NonUnitalStarSubalgebra.iSupLift K dir f hf T hT) x, hx = (f i) x
theorem NonUnitalStarSubalgebra.iSupLift_of_mem {R : Type u} {A : Type v} {B : Type w} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [NonUnitalSemiring B] [StarRing B] [Module R B] {ι : Type u_1} [StarRing R] [IsScalarTower R A A] [SMulCommClass R A A] [StarModule R A] [Nonempty ι] {K : ιNonUnitalStarSubalgebra R A} {dir : Directed (fun (x1 x2 : NonUnitalStarSubalgebra R A) => x1 x2) K} {f : (i : ι) → { x : A // x K i } →⋆ₙₐ[R] B} {hf : ∀ (i j : ι) (h : K i K j), f i = (f j).comp (NonUnitalStarSubalgebra.inclusion h)} {T : NonUnitalStarSubalgebra R A} {hT : T = iSup K} {i : ι} (x : { x : A // x T }) (hx : x K i) :
(NonUnitalStarSubalgebra.iSupLift K dir f hf T hT) x = (f i) x, hx

The center of a non-unital star algebra is the set of elements which commute with every element. They form a non-unital star subalgebra.

Equations
Equations
  • NonUnitalStarSubalgebra.instNonUnitalCommSemiring = NonUnitalSubalgebra.center.instNonUnitalCommSemiring
Equations
  • NonUnitalStarSubalgebra.instNonUnitalCommRing = NonUnitalSubalgebra.center.instNonUnitalCommRing
theorem NonUnitalStarSubalgebra.mem_center_iff {R : Type u} {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] {a : A} :
a NonUnitalStarSubalgebra.center R A ∀ (b : A), b * a = a * b

The centralizer of the star-closure of a set as a non-unital star subalgebra.

Equations
@[simp]
theorem NonUnitalStarSubalgebra.mem_centralizer_iff (R : Type u) {A : Type v} [CommSemiring R] [NonUnitalSemiring A] [StarRing A] [Module R A] [IsScalarTower R A A] [SMulCommClass R A A] {s : Set A} {z : A} :
z NonUnitalStarSubalgebra.centralizer R s gs, g * z = z * g star g * z = z * star g