Hi,
I have a XML doc
<A>
<A1>
<a2> 4 </a2>
    <a3> 6 </a3>
    <a4> 7 </a4>
</A1>
<A2>
    <a5> 2 </a5>
    <a6> 1 </a6>
    <a7> 7 </a7>
</A2>
<A3>
    <a8> 2 </a8>
    <a9> 1 </a9>
    <a10> 7 </a10>
</A3>
   <A4>
     ....</A4>
   ...
   <An>
   ....</An>
</A>

I have n number of nodes. Actually, I need to calculate determinant
of nxn matrix.
I need to do this calculation
(a6*a10+a7*a9)-(a7*a8+a5*a10)+(a5*a9+a8*a6)....


Please could anyone help me in writing this stylesheet? The main problem is how to navigate through this tree.

Try this:
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

    <xsl:variable name="a1" select="//a6*//a10+//a7*//a9"></xsl:variable>
    <xsl:variable name="a2" select="//a7*//a8+//a5*//a10"></xsl:variable>
    <xsl:variable name="a3" select="//a5*//a9+//a8*//a6"></xsl:variable>

    <xsl:template match="A">
        <xsl:value-of select="$a1 - $a2 + $a3"></xsl:value-of>
    </xsl:template>

</xsl:stylesheet>

------
Rummy