--- /dev/null
+
+strict digraph loopgraph {
+ rankdir=BT;
+ node[color=blue, fillcolor=lightblue, style=filled];
+
+ L1->L4->L8;
+ L2->L4->L6->L8; L6->L9;
+ L3->L5->L7->L9;
+ L1->L7;
+ node Rank0;
+ node Rank1;
+ node Rank2;
+
+ {rank=same; Rank0 L1 L2 L3}
+ {rank=same; Rank1 L4 L5}
+ {rank=same; Rank2 L6 L7}
+
+
+}
\ No newline at end of file