new file mode 100644

@@ -0,0 +1,8 @@

+digraph G {

+	subgraph cluster_c0 {a0 -> a1 -> a2 -> a3;}

+	subgraph cluster_c1 {b0 -> b1 -> b2 -> b3;}

+	x -> a0;

+	x -> b0;

+	a1 -> b3;

+	b3 -> a1;

+}