<models xmlns:xi="http://www.w3.org/2001/XInclude">
  <model name="BLOCK">
    <input_ports>
      <port clock="a" combinational_sink_ports="c" name="a"/>
      <port clock="a" name="b"/>
    </input_ports>
    <output_ports>
      <port clock="a" name="c"/>
    </output_ports>
  </model>
</models>