digraph {
  nd_0001 [
    shape=none
    
  label=<<table>
  <tr><td>a</td><td>b</td></tr>
  <tr><td>c</td><td>d</td></tr>
  <tr><td>e</td><td>f</td></tr>
</table>>
  ];

  nd_0002 [
    shape=none
    
  label=<<table>
  <tr><td              >d</td><td>e</td></tr>
  <tr><td port='port_f'>f</td><td>g</td></tr>
  <tr><td              >h</td><td>i</td></tr>
</table>>
  ];

  nd_0003 [
    shape=none
    
  label=<<table>
  <tr><td              >j</td><td port='port_k'>k</td></tr>
  <tr><td port='port_l'>l</td><td              >m</td></tr>
  <tr><td              >n</td><td              >o</td></tr>
</table>>
  ];

  nd_0004 [
    shape=none
    
  label="End"
  ];

nd_0001 -> nd_0002:port_f;
nd_0002:port_f -> nd_0003:port_l;
nd_0003:port_k -> nd_0004;
}