Xpath to count occurances within a single parent

Hello all,

I have the following XML structure

<book>
<chapter>
<caution/>
<caution/>
<caution/>
</chapter>

<chapter>
<sect1>
<caution/>
</sect1>
<caution/>
<caution/>
</chapter>
</book>

What I need is an XPATH statement that counts the number of preceding
cautions in each chapter.  From any given chapter element.

EXAMPLE:
count(preceding::caution)!= 0

This XPATH works correctly for the first <chapter> but fails on the second
<chapter> because one <caution> is a child of <sect1>.

Is there a way to count preceding <cautions> within a <chapter> element
despite nesting?

Thanks,

David White