 number of errors to unlimited.</dd>
<dt><tt>{~3}</tt></dt>
<dd>Sets the maximum number of errors to three.</dd>
<dt><tt>{+2~5}</tt></dt>
<dd>Sets the maximum number of errors to five, and the maximum number
of insertions to two.</dd>
<dt><tt>{&lt;3}</tt></dt>
<dd>Sets the maximum cost to three.
<dt><tt>{2i + d + 2s &lt; 5}</tt></dt>
<dd>Sets the cost of an insertion to two, a deletion to one, a
substitution to two, and the maximum cost to five.
</dl>


<h3>Bracket expressions</h3>
<a name="bracket-expressi