Implicit template for attributes

      <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">
                  <xxx>
                        <xsl:apply-templates  select="@a"/>
                  </xxx>
                  <yyy>
                        <xsl:apply-templates  select="*/@*"/>
                  </yyy>
            </xsl:template>

            <xsl:template  match="@b">
                  <bbb>
                        <xsl:value-of  select="string(.)"/>
                  </bbb>
            </xsl:template>

      </xsl:stylesheet>

      <aaa  a="1">
            <bbb  b="2"/>
            <ccc  c="3"/>
      </aaa>

      <xxx>1</xxx>
      <yyy>
            <bbb>2</bbb>3
      </yyy>