XSL:FO - how to render a single footnote for multiple,

Hi,

Is there a way to output a single footnote for multiple, identical XML
footnote entries in pdf?

For example, a document that has 2 identical footnotes:

foo <footnote notetext="footnote text" opid="fn1"/>
bar <footnote notetext="footnote text" opid="fn1"/>

outputs:

foo1
foo2
------------
1. footnote text
2. footnote text

instead of:

foo1
bar1
-------------
1. footnote text

I created an XML element that cross-references an existing, identical
footnote.

<xref toFootnote="yes id="fn1"/>

I want to write an XSL stylesheet that processes the xreftoFootnote
element by outputting the footnote number of the referenced footnote.  I
have the ID of the referenced footnote but can think of no way to access
the footnote number. Is there a way to save the footnote IDs and
footnote numbers in memory so that the xreftoFootnote template could
retrieve the footnote number for a particular ID?

Thanks for any suggestions on solving this problem.

Ann Marie