Processing instructions

      <xsl:stylesheet
                  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                  version="2.0">
            <xsl:output  method="xml"
                        indent="yes"
                        omit-xml-declaration="yes"/>

            <xsl:template  match="/aaa">
                  <xsl:processing-instruction  name="eq">
                        <xsl:text>a=9; b=</xsl:text>
                        <xsl:value-of  select="string-length(.)"/>
                  </xsl:processing-instruction>
                  <bbb>
                        <ccc>
                              <xsl:processing-instruction  name="eq"
                                          select="."/>
                        </ccc>
                  </bbb>
            </xsl:template>

      </xsl:stylesheet>

      <aaa>a=2; b=4</aaa>

<?eq a=9; b=8?>
      <bbb>
            <ccc><?eq a=2; b=4?></ccc>
      </bbb>