Extension functions and XSLT 2.0

I am currently writing an XSLT 2.0 (basic level) processor, and I'm an
currently using the xhtml docbook stylesheets to drive my development.

I notice that in verbatim.xsl, there is the following:

<xsl:template name="make-verbatim">
  <xsl:param name="rtf"/>

  <!-- I want to make this RTF verbatim. There are two possibilities: either
       I have access to the exsl:node-set extension function and I can "do it right"
       or I have to rely on CSS. -->

  <xsl:choose>
    <xsl:when test="function-available('exsl:node-set')">
      <xsl:apply-templates select="exsl:node-set($rtf)" mode="make.verbatim.mode"/>
    </xsl:when>
    <xsl:otherwise>
      <span style="white-space: pre;">
        <xsl:copy-of select="$rtf"/>
      </span>
    </xsl:otherwise>
  </xsl:choose>
</xsl:template>

Now since XSLT has no need for a node-set extension function, I do not
propose to write one. Can the code be updated to accomodate this
possiblity?

-- 
Colin Paul Adams
Preston Lancashire