digraph{ node[shape=record width=.2 height=.1] 1[label=" |1|"] 2[label="|2|"] 3[label=" |3|"] 4[label=" |4|"] 5[label=" |5|"] 6[label=" |6|"] 7[label=" |7|"] 8[label=" |8|"] 9[label=" |9|"] 3->6->9 3:f0->1:f1 1->2 3:f2->4:f1 4->5 6:f0->4:f1 6:f2->7:f1 7->8 9:f0->7:f1 {rank=same; 3, 6, 9} {rank=same; 1, 2} {rank=same; 4, 5} {rank=same; 7, 8} }