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<record version="3" id="3690">
 <title>nil and nilpotent ideals</title>
 <name>NilAndNilpotentIdeals</name>
 <created>2002-12-08 18:48:35</created>
 <modified>2003-09-04 20:04:30</modified>
 <type>Definition</type>
 <creator id="549" name="mclase"/>
 <author id="549" name="mclase"/>
 <classification>
	<category scheme="msc" code="16N40"/>
 </classification>
 <defines>
	<concept>nil</concept>
	<concept>nil ring</concept>
	<concept>nil ideal</concept>
	<concept>nil right ideal</concept>
	<concept>nil left ideal</concept>
	<concept>nil subring</concept>
	<concept>nilpotent</concept>
	<concept>nilpotent element</concept>
	<concept>nilpotent ring</concept>
	<concept>nilpotent ideal</concept>
	<concept>nilpotent right ideal</concept>
	<concept>nilpotent left ideal</concept>
	<concept>nilpotent subring</concept>
	<concept>locally nilpotent</concept>
	<concept>locally nilpotent ring</concept>
	<concept>locally nilpotent ideal</concept>
	<concept>locally nilpotent right ideal</concept>
	<concept>locally nilpotent left ideal</concept>
	<concept>locally nilpotent subring</concept>
 </defines>
 <related>
	<object name="KoetheConjecture"/>
 </related>
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 <content>An element $x$ of a ring is \emph{nilpotent} if $x^n = 0$ for some positive integer $n$.

A ring $R$ is \emph{nil} if every element in $R$ is nilpotent.  Similarly, a one- or two-sided ideal is called \emph{nil} if each of its elements is nilpotent.

A ring $R$ [resp. a one- or two sided ideal $A$] is \emph{nilpotent} if $R^n = 0$ [resp. $A^n = 0$] for some positive integer $n$.

A ring or an ideal is \emph{locally nilpotent} if every finitely generated subring is nilpotent.

The following implications hold for rings (or ideals):

$$\text{nilpotent} \quad\Rightarrow \text{locally nilpotent} \quad\Rightarrow \text{nil}$$</content>
</record>
