If $*$ is a binary operation on a set $A$, then $A$ has an **identity** element with respect to $*$ if there exists $e\in A$ such that for all $a\in A$,
$$ a*e = e*a = a.$$
Such an identity element $e$, if it exists, is unique and is thus called **the identity element** of $A$ with respect to $*$.

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- Review status: reviewed
- Last edited by Holly Swisher on 2019-04-26 13:42:52

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**History:**(expand/hide all)

- 2019-04-26 13:42:52 by Holly Swisher (Reviewed)
- 2019-04-26 13:42:10 by Holly Swisher
- 2019-04-26 13:41:33 by Holly Swisher
- 2019-04-26 13:41:16 by Holly Swisher
- 2019-04-26 13:40:51 by Holly Swisher
- 2019-04-26 13:39:10 by Holly Swisher
- 2019-04-26 13:38:17 by Holly Swisher
- 2019-04-26 13:37:12 by Holly Swisher
- 2018-08-06 02:21:34 by John Jones

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