or a subpattern can be changed
by appending <i>approx-settings</i> to the subpattern.  Limits for
the number of errors can be set and an expression for specifying and
limiting the costs can be given.
</p>

<p>
The <i>count-limits</i> can be used to set limits for the number of
insertions (<tt>+</tt>), deletions (<tt>-</tt>), substitutions
(<tt>#</tt>), and total number of errors (<tt>~</tt>).  If the
<i>number</i> part is omitted, the specified error count will be
unlimited.
</p>

<p>
The <i>cost-equation</