> works with Saxonb 8 and Xalan 2.6.0, whereas
> 
> <xsl:with-param name="number"
>     select="(preceding::footnote)/(preceding::endnote)" />
> 
> works with Saxon but gives the following error in Xalan:
> 

This syntax is legal in XPath 2.0 but not in XPath 1.0.

Michael Kay