generating main file junk1152042-00.xml
generating junk1152042-01.xml
generating junk1152042-02.xml

$ cat junk1152042-00.xml
<Root>
  <Top>
    <xi:include href="junk1152042-01.xml"/>
    <xi:include href="junk1152042-02.xml"/>
    <input name="add"/>
    <input name="clk"/>
    <input name="da_in"/>
    <output name="da_out"/>
    <bidirection name="ctrl"/>
  </Top>
</Root>

$ cat junk1152042-01.xml
<Module name="ALU">
      <input name="po_ctrl"/>
      <bidirection name="add"/>
    </Module>
$ cat junk1152042-02.xml
<Module name="Po_ctrl">
      <input name="ctrl"/>
      <output name="ctrlbus"/>
      <bidirection name="add"/>
    </Module>
$