<diputree>
<has>
<b>
<lt>level 1</lt>
<has>
<b>
<lt>level 2</lt>
<has>
<b/>
</has>
</b>
</has>
</b>
</has>
</diputree>
<diputree> <has> a <b>ranch with a <lt> (label text) level 1 which itself <has> a <b>
with <lt> level 2 which itself <has> an empty <b/>
with no label.
<b> (branch), <l> (leaf) and <diputree>