digraph g {
  fontname=Helvetica;
  compound=true;
  graph [

    rankdir=LR
    splines=false overlap=false 
    ranksep=0.0 nodesep=0.5
  ]


  node[style=filled shape=underline penwidth=1 fillcolor="white" fontname = "Courier New"];

  node [label =<
    <table border="0" cellborder="0" cellpadding="3" bgcolor="white">
    <tr>
      <td align="center" bgcolor="white"><font color="white">123456</font></td>
    </tr>
    </table>> ];

  NF1 NF2 NF3 NF4;
  
  node [label =<
    <table border="0" cellborder="1" cellpadding="3" bgcolor="white">
    <tr>
      <td align="center" bgcolor="gray80"><font color="gray80">123456</font></td>
    </tr>
    </table>> ];

  NL1 NL2 NL3 NL4;

  node [label =<
    <table border="0" cellborder="1" cellpadding="3" bgcolor="white">
    <tr>
      <td align="center" bgcolor="white"><font color="white">123456</font></td>
    </tr>
    </table>> ]

  NE1 NE2 NE3 NE4;

  node [shape=plain fontsize=12 fontname=Helvetica label="." style=filled width=1.0 height=0]
  END_FF [label="1"]
  END_EF [label="2"]

  END_LF [label="3"]

  END_LE [label="4"]
  END_EE [label="5"]

  END_LL [label="6"] 
  
  subgraph cluster_vehicle_states 
  {
    graph [margin=16 peripheries=1 penwidth=0.5]
    {
    graph [label="" margin=12 peripheries=1 penwidth=0.5]
  
  
   subgraph cluster_ff {
    {
    NF1 -> NF2 [style=solid arrowhead=none]
    NF2 -> END_FF [style=invis]
    }
  }

  subgraph cluster_ef { 
    {
    NE4 -> NF4 [style=solid arrowhead=none]
    NF4 -> END_EF [style=invis]
  }
  }

  subgraph cluster_lf { 
    {
    NL4 -> NF3 [style=solid arrowhead=none]
    NF3 -> END_LF [style=invis]
    }
  }


  subgraph cluster_le { 
    {
    NL3 -> NE3 [style=solid arrowhead=none]
    NE3 -> END_LE [style=invis]
    }
  }

    subgraph cluster_ee { 
    {
    NE1 -> NE2 [style=solid arrowhead=none]
    NE2 -> END_EE [style=invis]
    }
  }

    subgraph cluster_ll {
    {
    NL1 -> NL2 [style=solid arrowhead=none]
    NL2 -> END_LL [style=invis]
    }
  }

  }

  }
  
}