digraph small_nfa {
	graph [rankdir="LR"];
	node [shape="circle"];
	zz [label="" width=0.01 height=0.01];
	0 [shape=doublecircle label="s0"];
	1 [label="s1"];
	2 [shape=doublecircle label="s2"];
	3 [label="s3"];
	0 -> 1 [label="e0/a"]
	1 -> 1 [label="e1/nil"]
	1 -> 2 [label="e2/b"]
	1 -> 3 [label="e3/b"]
	2 -> 3 [label="e4/c"]
	3 -> 0 [label="e5/a"]
	2 -> 1 [label="e6/nil"]
	zz -> 0 [label=""]
	zz -> 3 [label=""]
}