Question for the masses...

Lets say I have variable with the following contents
"aaaa bbbb ccccc dddd".  The format is not specific and the space
delimiter could be changed to any other.

How would i count and/or select the nodes where a child nodes value is
not contained in this list.  Or the reverse scenario would be sufficent
whereas I count the nodes whose child nodes value is contained.

A contrived example of my situation follows...thanks for the help.

<root>
<limbs>
<branch>
<name>a</name>
<flower>big</flower>
</branch>
<branch>
<name>b</name>
<flower>big</flower>
</branch>
<branch>
<name>c</name>
<flower>large</flower>
</branch>
<branch>
<name>d</name>
<flower>giant</flower>
</branch>
</limbs>
<root>

<xsl:stylesheet	version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="html" indent="yes" omit-xml-declaration="yes"/>
<xsl:variable name="Exclude">
<xsl:value-of select="big large"/>
</xsl:variable>
<xsl:template match="/">
<xsl:variable name="DomainCount">
<xsl:value-of select="count(//branch[contains($Exclude,
flower)])"/>
      </xsl:variable>
	</xsl:template>
</xsl:stylesheet>