Hi,

> I have the following XML:
> ?
> ?
> <Specification_expression id="specification_expression-1">
> ??????<id>teste</id>
> ????? <description>teste</description>
> ????? <operation>or_operator</operation>
> ????? <operand>
> ?????????? <sos ref="sos-1"/>
> ????? </operand>
> ?</Specification_expression>
> ??
> ?<sos id="sos-1">
> ??<Specification ref="specification-7"/>
> ?</sos>

I assume these two XML fragments exist in the same document. If so,

  <xsl:template match="sos[@ref]">
    <xsl:copy>
      <xsl:apply-templates select="//sos[@id = current()/@ref]/node()"/>
    </xsl:copy>
  </xsl:template>
  <xsl:template match="sos[@id]"/>
  <xsl:template match="@* | node()">
    <xsl:copy>
      <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
  </xsl:template>

Will get you there. If you have a DTD that defines the "id" attribute as an ID, then

  <xsl:apply-templates select="id(@ref)/node()"/>

Will also get you there-again, there are other ways, too.

Cheers,

Jarno - This Morn' Omina: One Eyed Man

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list