Matching only one of many unknown nodes with xpath

Hello.

Im trying to match only one of each node with a generic match. Can this be done generic at all? I would have prefered to just match one of each node with the same local-name()

<xsl:variable name="xmltree">
  <node />
  <anothernode />
  <node />
  <anothernode />
  <unknown />
  <anothernode />
  <node />
  <unknown />
</xsl:variable>

<xsl:template match="/">
  <xsl:apply-templates select="$xmltree/*" mode="MODULE"/>
</xsl:template>

<xsl:template match="*" mode="MODULE" /> <!-- EMPTY MATCH -->

<xsl:template match="node[1]|anothernode[1]|unknown[1]" mode="MODULE">
  <!-- Do something -->
</xsl:template>

From stackoverflow

• This is a grouping question and in XSLT 1.0 the most efficient way to do grouping is the Muenchian method.

  If the number of elements is not too-big, the following short code might be sufficient:

  <xsl:stylesheet version="1.0"
   xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  
   <xsl:output omit-xml-declaration="yes" indent="yes"/>
   <xsl:strip-space elements="*"/>
  
      <xsl:template match="/*/*">
       <xsl:copy-of select=
        "self::*[not(preceding-sibling::*
                        [name() = name(current())]
                     )
                 ]"/>
      </xsl:template>
  </xsl:stylesheet>
  

  When this transformation is applied on the following source XML document:

  <t>
      <node />
      <anothernode />
      <node />
      <anothernode />
      <unknown />
      <anothernode />
      <node />
      <unknown />
  </t>
  

  The wanted result is produced:

  <node/>
  <anothernode/>
  <unknown/>
  

  One may study the XPath expressions used in order to understand that this transformation copies really every first occurence of an element with a specific name.

  Sveisvei : Thank you. This will solve it. Thanx Dimitre(the xslt-master).