ring.dot

graph ring {
 p1 [algo="p.ml"]
 p2 [algo="p.ml"]
 p3 [algo="p.ml"]
 p4 [algo="p.ml"]
 p5 [algo="p.ml"]
 p6 [algo="p.ml"]
 p7 [algo="p.ml"]

 p1 -- p2 -- p3 -- p4 -- p5 -- p6 -- p7 -- p1 
}