Jump to content

Power associativity: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
m from Power_associative
m Automated conversion
Line 1: Line 1:
An [[algebra]] ''A'' is called '''power-associative''' if the subalgebra generated by any element of ''A'' is [[associative]].
In [[abstract algebra]], '''power-associativity''' is a weak form of [[associative|associativity]]


A [[groupoid]] (in the sense of a [[set]] with a [[binary operation]] on it) is said to be power-associative if every element generates a [[semigroup|subsemigroup]].
This is equivalent to saying that ''x''<sup>m</sup>''x''<sup>n</sup> = ''x''<sup>m+n</sup> for every ''x'' in the groupoid.

Similarly, and more commonly, an [[algebra]] ''A'' is said to be power-associative if the subalgebra generated by any element of ''A'' is associative.
This is equivalent to the multiplicative groupoid of ''A'' being power-associative.
Every [[associative algebra]] is obviously power-associative, and so too are the [[octonions]] and the [[sedenions]].

Revision as of 15:43, 25 February 2002

In abstract algebra, power-associativity is a weak form of associativity

A groupoid (in the sense of a set with a binary operation on it) is said to be power-associative if every element generates a subsemigroup. This is equivalent to saying that xmxn = xm+n for every x in the groupoid.

Similarly, and more commonly, an algebra A is said to be power-associative if the subalgebra generated by any element of A is associative. This is equivalent to the multiplicative groupoid of A being power-associative. Every associative algebra is obviously power-associative, and so too are the octonions and the sedenions.