<!--
     XPath 1.0 and XPath 2.0 in a single (concat) statement

     (4=5)=/..  is true for XPath 1.0 and false for XPath 2.0
     [comparison of  false  and  empty nodeset]
     https://twitter.com/HermannSW/statuses/373151343029936129

     dp:xquery-transform(_, _)  is new in 7.0.0.0 firmware
-->
<xsl:stylesheet version="1.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:dp="http://www.datapower.com/extensions"
  extension-element-prefixes="dp"
>
  <xsl:template match="/">
    <xsl:value-of select="
      concat(
        (4=5)=/.. ,
        dp:xquery-transform('http://stamm-wilbrandt.de/en/blog/isXPath1.xq', .)
      )"
    />
  </xsl:template>

</xsl:stylesheet>