class sage.categories.rngs.Rngs(base_category)#

Bases: sage.categories.category_with_axiom.CategoryWithAxiom_singleton

The category of rngs.

An rng \((S, +, *)\) is similar to a ring but not necessarily unital. In other words, it is a combination of a commutative additive group \((S, +)\) and a multiplicative semigroup \((S, *)\), where \(*\) distributes over \(+\).


sage: C = Rngs(); C
Category of rngs
sage: sorted(C.super_categories(), key=str)
[Category of associative additive commutative additive associative additive unital distributive magmas and additive magmas,
 Category of commutative additive groups]

sage: sorted(C.axioms())
['AdditiveAssociative', 'AdditiveCommutative', 'AdditiveInverse',
 'AdditiveUnital', 'Associative', 'Distributive']

sage: C is (CommutativeAdditiveGroups() & Semigroups()).Distributive()
sage: C.Unital()
Category of rings

alias of sage.categories.rings.Rings