Problems with string comparison using

Question

I have a problem using the > and < comparison operators.
When the xsl:if test uses numeric values the comparison works OK. If the
test uses string values it always returns a false result.
The style sheet below shows an example (which should run against any
XML doc with a root element)
Note - the spurious
tags are just for debugging- I write the
output to an HTML page and IE happens to recognise them
even though the rest of the HTML tags are missing !!
<?xml version="1.0" ?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" >
<xsl:template match="/">
<xsl:for-each select="*">
Starting numeric test :
<xsl:if test="(1 < 2)">
In Test, ID= <xsl:value-of select="generate-id()"/>
</xsl:if>
Finished numeric test :
Starting alpha test :
<xsl:if test="('a' < 'b')">
In Test, ID= <xsl:value-of select="generate-id()"/>
</xsl:if>
Finished alpha test :
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
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Answer 1

Having looked at the XPath spec I believe what I am trying to do (compare strings with gt and lt type tests) is not supported. The spec indicates that they can only be used for node sets or numerics. Presumably the processor is attempting to convert the values to numbers but evaluating them both as NaN (not a number). Can someone confirm this.
I find this restriction quite strange, is this a situation where an extension function is required ? If so can someone point me to some (Java) examples.
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