Signed Tensor Product Functorial Construction¶
AUTHORS:
 Travis Scrimshaw (201907): initial version

class
sage.categories.signed_tensor.
SignedTensorProductFunctor
¶ Bases:
sage.categories.covariant_functorial_construction.CovariantFunctorialConstruction
A singleton class for the signed tensor functor.
This functor takes a collection of graded algebras (possibly with basis) and constructs the signed tensor product of those algebras. If this algebra is in a subcategory, say that of
Algebras(QQ).Graded()
, it is automatically endowed with its natural algebra structure, thanks to the categoryAlgebras(QQ).Graded().SignedTensorProducts()
of signed tensor products of graded algebras.The signed tensor functor is covariant: if
A
is a subcategory ofB
, thenA.SignedTensorProducts()
is a subcategory ofB.SignedTensorProducts()
(see alsoCovariantFunctorialConstruction
). Hence, the role ofAlgebras(QQ).Graded().SignedTensorProducts()
is solely to provide mathematical information and algorithms which are relevant to signed tensor product of graded algebras.Those are implemented in the nested class
SignedTensorProducts
ofAlgebras(QQ).Graded()
. This nested class is itself a subclass ofSignedTensorProductsCategory
.EXAMPLES:
sage: tensor_signed The signed tensor functorial construction

class
sage.categories.signed_tensor.
SignedTensorProductsCategory
(category, *args)¶ Bases:
sage.categories.covariant_functorial_construction.CovariantConstructionCategory
An abstract base class for all SignedTensorProducts’s categories.

SignedTensorProducts
()¶ Return the category of signed tensor products of objects of
self
.By associativity of signed tensor products, this is
self
(a tensor product of signed tensor products of \(Cat\)’s is a tensor product of \(Cat\)’s with the same twisting morphism)EXAMPLES:
sage: AlgebrasWithBasis(QQ).Graded().SignedTensorProducts().SignedTensorProducts() Category of signed tensor products of graded algebras with basis over Rational Field

base
()¶ The base of a signed tensor product is the base (usually a ring) of the underlying category.
EXAMPLES:
sage: AlgebrasWithBasis(ZZ).Graded().SignedTensorProducts().base() Integer Ring


sage.categories.signed_tensor.
tensor_signed
= The signed tensor functorial construction¶