Adding Variables

Hi All,
I've created a number of xsl variables in my template
and I now wish to add these variables together and
render the result in my template. For example,

<xsl:variable name="num1">
<xsl:value-of select="//test1/somevalue1"/>
</xsl:variable>

and

<xsl:variable name="num2">
<xsl:value-of select="//test2/somevalue2"/>
</xsl:variable>

Trying <xsl:value-of select="$num1+$num2"/> doesn't
work.

How can I add the results of my two variables above
and render the result in my template using a
xsl:value-of or similar.
Many thanks in advance.
JD


	
		
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