# Non-unital non-associative algebras¶

class sage.categories.magmatic_algebras.MagmaticAlgebras(base, name=None)

The category of algebras over a given base ring.

An algebra over a ring $$R$$ is a module over $$R$$ endowed with a bilinear multiplication.

Warning

MagmaticAlgebras will eventually replace the current Algebras for consistency with e.g. Wikipedia article Algebras which assumes neither associativity nor the existence of a unit (see trac ticket #15043).

EXAMPLES:

sage: from sage.categories.magmatic_algebras import MagmaticAlgebras
sage: C = MagmaticAlgebras(ZZ); C
Category of magmatic algebras over Integer Ring
sage: C.super_categories()
Category of modules over Integer Ring]


TESTS:

sage: TestSuite(C).run()

Associative

alias of AssociativeAlgebras

class ParentMethods
algebra_generators()

Return a family of generators of this algebra.

EXAMPLES:

sage: F = AlgebrasWithBasis(QQ).example(); F
An example of an algebra with basis: the free algebra on the generators ('a', 'b', 'c') over Rational Field
sage: F.algebra_generators()
Family (B[word: a], B[word: b], B[word: c])

MagmaticAlgebras.Unital

alias of UnitalAlgebras

class MagmaticAlgebras.WithBasis(base_category)

TESTS:

sage: C = Modules(ZZ).FiniteDimensional(); C
Category of finite dimensional modules over Integer Ring
sage: type(C)
<class 'sage.categories.modules.Modules.FiniteDimensional_with_category'>
sage: type(C).__base__.__base__
<class 'sage.categories.category_with_axiom.CategoryWithAxiom_over_base_ring'>

sage: TestSuite(C).run()

class ParentMethods
product()

The product of the algebra, as per Magmas.ParentMethods.product()

By default, this is implemented using one of the following methods, in the specified order:

EXAMPLES:

sage: A = AlgebrasWithBasis(QQ).example()
sage: a, b, c = A.algebra_generators()
sage: A.product(a + 2*b, 3*c)
3*B[word: ac] + 6*B[word: bc]

product_on_basis(i, j)

The product of the algebra on the basis (optional).

INPUT:

• i, j – the indices of two elements of the basis of self

Return the product of the two corresponding basis elements indexed by i and j.

If implemented, product() is defined from it by bilinearity.

EXAMPLES:

sage: A = AlgebrasWithBasis(QQ).example()
sage: Word = A.basis().keys()
sage: A.product_on_basis(Word("abc"),Word("cba"))
B[word: abccba]


Return None.

Indeed, the category of (magmatic) algebras defines no new structure: a morphism of modules and of magmas between two (magmatic) algebras is a (magmatic) algebra morphism.

Todo

This category should be a CategoryWithAxiom, the axiom specifying the compability between the magma and module structure.

EXAMPLES:

sage: from sage.categories.magmatic_algebras import MagmaticAlgebras

MagmaticAlgebras.super_categories()

EXAMPLES:

sage: from sage.categories.magmatic_algebras import MagmaticAlgebras
sage: MagmaticAlgebras(ZZ).super_categories()
[Category of additive commutative additive associative additive unital distributive magmas and additive magmas, Category of modules over Integer Ring]