<stx:transform version="1.0" 
  xmlns:stx="http://stx.sourceforge.net/2002/ns"
  strip-space="yes">

  <stx:template match="*">
    <stx:element name="{name()}">
      <stx:attribute name="c" select="has-child-nodes()"/>
      <stx:process-children/>
    </stx:element>
  </stx:template>

  <stx:template match="text()[1]|comment()|processing-instruction()">
    <n c="{has-child-nodes()}"/>
  </stx:template>
  
</stx:transform>