Non-unital Star Subalgebras #
In this file we define NonUnitalStarSubalgebra
s and the usual operations on them
(map
, comap
).
TODO #
- once we have scalar actions by semigroups (as opposed to monoids), implement the action of a non-unital subalgebra on the larger algebra.
If a type carries an involutive star, then any star-closed subset does too.
Equations
- StarMemClass.instInvolutiveStar s = InvolutiveStar.mk (_ : ∀ (r : ↥s), star (star r) = r)
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
- StarMemClass.instStarMul s = StarMul.mk (_ : ∀ (x x_1 : ↥s), star (x * x_1) = star x_1 * star x)
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
- StarMemClass.instStarAddMonoid s = StarAddMonoid.mk (_ : ∀ (x x_1 : ↥s), star (x + x_1) = star x + star x_1)
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
- StarMemClass.instStarRing s = let src := StarMemClass.instStarMul s; let src_1 := StarMemClass.instStarAddMonoid s; StarRing.mk (_ : ∀ (r s_1 : ↥s), star (r + s_1) = star r + star s_1)
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
- (_ : StarModule R ↥s) = (_ : StarModule R ↥s)
Embedding of a non-unital star subalgebra into the non-unital star algebra.
Equations
- One or more equations did not get rendered due to their size.
Instances For
A non-unital star subalgebra is a non-unital subalgebra which is closed under the star
operation.
- carrier : Set A
- zero_mem' : 0 ∈ self.carrier
The
carrier
of aNonUnitalStarSubalgebra
is closed under thestar
operation.
Instances For
Equations
- One or more equations did not get rendered due to their size.
Equations
- (_ : NonUnitalSubsemiringClass (NonUnitalStarSubalgebra R A) A) = (_ : NonUnitalSubsemiringClass (NonUnitalStarSubalgebra R A) A)
Equations
- (_ : SMulMemClass (NonUnitalStarSubalgebra R A) R A) = (_ : SMulMemClass (NonUnitalStarSubalgebra R A) R A)
Equations
- (_ : StarMemClass (NonUnitalStarSubalgebra R A) A) = (_ : StarMemClass (NonUnitalStarSubalgebra R A) A)
Equations
- (_ : NonUnitalSubringClass (NonUnitalStarSubalgebra R A) A) = (_ : NonUnitalSubringClass (NonUnitalStarSubalgebra R A) A)
Copy of a non-unital star subalgebra with a new carrier
equal to the old one.
Useful to fix definitional equalities.
Equations
- NonUnitalStarSubalgebra.copy S s hs = let src := NonUnitalSubalgebra.copy S.toNonUnitalSubalgebra s hs; { toNonUnitalSubalgebra := src, star_mem' := (_ : ∀ x ∈ s, star x ∈ s) }
Instances For
A non-unital star subalgebra over a ring is also a Subring
.
Equations
- NonUnitalStarSubalgebra.toNonUnitalSubring S = { toNonUnitalSubsemiring := S.toNonUnitalSubsemiring, neg_mem' := (_ : ∀ {x : A}, x ∈ S → -x ∈ S) }
Instances For
Equations
- NonUnitalStarSubalgebra.instInhabited S = { default := 0 }
NonUnitalStarSubalgebra
s inherit structure from their NonUnitalSubsemiringClass
and
NonUnitalSubringClass
instances.
Equations
- NonUnitalStarSubalgebra.toNonUnitalSemiring S = inferInstance
Equations
- NonUnitalStarSubalgebra.toNonUnitalCommSemiring S = inferInstance
Equations
- NonUnitalStarSubalgebra.toNonUnitalRing S = inferInstance
Equations
- NonUnitalStarSubalgebra.toNonUnitalCommRing S = inferInstance
The forgetful map from NonUnitalStarSubalgebra
to NonUnitalSubalgebra
as an
OrderEmbedding
Equations
- One or more equations did not get rendered due to their size.
Instances For
NonUnitalStarSubalgebra
s inherit structure from their Submodule
coercions.
Equations
- NonUnitalStarSubalgebra.module' S = SMulMemClass.toModule' (NonUnitalStarSubalgebra R A) R' R A S
Equations
- (_ : IsScalarTower R' R ↥S) = (_ : IsScalarTower R' R ↥S.toNonUnitalSubalgebra)
Equations
- (_ : IsScalarTower R ↥S ↥S) = (_ : IsScalarTower R ↥S ↥S)
Equations
- (_ : SMulCommClass R' R ↥S) = (_ : SMulCommClass R' R ↥S)
Equations
- (_ : SMulCommClass R ↥S ↥S) = (_ : SMulCommClass R ↥S ↥S)
Equations
- (_ : NoZeroSMulDivisors R ↥S) = (_ : NoZeroSMulDivisors R ↥S)
Transport a non-unital star subalgebra via a non-unital star algebra homomorphism.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Preimage of a non-unital star subalgebra under a non-unital star algebra homomorphism.
Equations
- NonUnitalStarSubalgebra.comap f S = { toNonUnitalSubalgebra := NonUnitalSubalgebra.comap f S.toNonUnitalSubalgebra, star_mem' := (_ : ∀ (a : A), f a ∈ S → f (star a) ∈ S) }
Instances For
Equations
- (_ : NoZeroDivisors ↥S) = (_ : NoZeroDivisors ↥S)
A non-unital subalgebra closed under star
is a non-unital star subalgebra.
Equations
- NonUnitalSubalgebra.toNonUnitalStarSubalgebra s h_star = { toNonUnitalSubalgebra := s, star_mem' := h_star }
Instances For
Range of an NonUnitalAlgHom
as a NonUnitalStarSubalgebra
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Restrict the codomain of a non-unital star algebra homomorphism.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Restrict the codomain of a non-unital star algebra homomorphism f
to f.range
.
This is the bundled version of Set.rangeFactorization
.
Equations
- NonUnitalStarAlgHom.rangeRestrict f = NonUnitalStarAlgHom.codRestrict f (NonUnitalStarAlgHom.range f) (_ : ∀ (x : A), f x ∈ NonUnitalStarAlgHom.range f)
Instances For
The equalizer of two non-unital star R
-algebra homomorphisms
Equations
- One or more equations did not get rendered due to their size.
Instances For
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.
Instances For
Restrict an injective non-unital star algebra homomorphism to a star algebra isomorphism
Equations
- StarAlgEquiv.ofInjective' f hf = StarAlgEquiv.ofLeftInverse' (_ : Function.LeftInverse (Classical.choose (_ : Function.HasLeftInverse ⇑f)) ⇑f)
Instances For
The star closure of a subalgebra #
The pointwise star
of a non-unital subalgebra is a non-unital subalgebra.
Equations
- NonUnitalSubalgebra.instInvolutiveStar = InvolutiveStar.mk (_ : ∀ (S : NonUnitalSubalgebra R A), star (star S) = S)
The star operation on NonUnitalSubalgebra
commutes with NonUnitalAlgebra.adjoin
.
The NonUnitalStarSubalgebra
obtained from S : NonUnitalSubalgebra R A
by taking the
smallest non-unital subalgebra containing both S
and star S
.
Equations
Instances For
The minimal non-unital subalgebra that includes s
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Galois insertion between adjoin
and Subtype.val
.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
- One or more equations did not get rendered due to their size.
NonUnitalStarAlgHom
to ⊤ : NonUnitalStarSubalgebra R A
.
Equations
- NonUnitalStarAlgebra.toTop = NonUnitalStarAlgHom.codRestrict (NonUnitalStarAlgHom.id R A) ⊤ (_ : ∀ (x : A), (NonUnitalStarAlgHom.id R A) x ∈ ⊤)
Instances For
Equations
- (_ : Subsingleton (NonUnitalStarSubalgebra R A)) = (_ : Subsingleton (NonUnitalStarSubalgebra R A))
Equations
- (_ : Subsingleton (A →⋆ₙₐ[R] B)) = (_ : Subsingleton (A →⋆ₙₐ[R] B))
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
- One or more equations did not get rendered due to their size.
Instances For
The product of two non-unital star subalgebras is a non-unital star subalgebra.
Equations
- One or more equations did not get rendered due to their size.
Instances For
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.
Instances For
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
- NonUnitalStarSubalgebra.center R A = { toNonUnitalSubalgebra := NonUnitalSubalgebra.center R A, star_mem' := (_ : ∀ {a : A}, a ∈ Set.center A → star a ∈ Set.center A) }
Instances For
Equations
- NonUnitalStarSubalgebra.instNonUnitalCommSemiring = NonUnitalSubalgebra.center.instNonUnitalCommSemiring
Equations
- NonUnitalStarSubalgebra.instNonUnitalCommRing = NonUnitalSubalgebra.center.instNonUnitalCommRing
The centralizer of the star-closure of a set as a non-unital star subalgebra.
Equations
- One or more equations did not get rendered due to their size.