Difference between revisions of "Associative ring"

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{{non-associative ring property}}
 
==Definition==
 
==Definition==
  
A '''ring''' is a set <math>R</math> equipped with the following operations:
+
An '''associative ring''', sometimes termed a '''ring''', is a set <math>R</math> equipped with the following operations:
  
 
* An infix binary operation <math>+</math>, called ''addition''.
 
* An infix binary operation <math>+</math>, called ''addition''.

Latest revision as of 18:10, 3 March 2010

This article defines a non-associative ring property: a property that an be evaluated to true or false for any non-associative ring.
View other non-associative ring properties

Definition

An associative ring, sometimes termed a ring, is a set R equipped with the following operations:

  • An infix binary operation +, called addition.
  • A prefix unary operation -, called the negative.
  • A constant element 0, called zero.
  • A binary operation *, called the multiplication.

satisfying the following compatibility conditions:

  • R forms an abelian group with group operation +, inverse operation -, and identity element 0.
  • R satisfies the two distributivity laws:
    • a * (b + c) = (a * b) + (a * c) \ \forall \ a,b,c \in R
    • (a + b) * c = (a * c) + (b * c) \ \forall \ a,b,c \in R
  • Associativity: a * (b * c) = (a * b) * c \ \forall \ a,b,c \in R

However, in many contexts, it is useful to study the situation where * is possibly non-associative, i.e., we want to remove the last condition from the definition. We use the term non-associative ring for a ring that is not necessarily associative. Note that associative rings are non-associative rings by this definition.

A unital ring or unitary ring is a ring with an identity for multiplication, denoted 1. A commutative ring is a ring where the multiplication is commutative. A commutative unital ring is a ring where the multiplication is both commutative and has a unit.