digraph Fibonnacci {
	#bgcolor="transparent"
	"fib(6)" -> {fib4 [label="fib(4)"] fib5 [label="fib(5)"]}
	
	subgraph cluster1 {
		style="rounded,dashed";
		fib4 -> {fib2 [label="fib(2)"] fib3 [label="fib(3)"]}
			subgraph cluster1 {
			style="rounded,dotted";
			fib3 -> {fib1 [label="fib(1)"] fib22 [label="fib(2)"]}
			}
	}

	fib5 -> {fib33 [label="fib(3)"] fib44 [label="fib(4)"]};

	subgraph cluster2 {
		style="rounded,dotted";
		fib33 -> {fib11 [label="fib(1)"] fib222 [label="fib(2)"]};
	}
	
	subgraph cluster3 {
		style="rounded,dashed";
		fib44 -> {fib2222 [label="fib(2)"] fib333 [label="fib(3)"]}
		subgraph cluster4 {
			style="rounded,dotted";
			fib333 -> {fib111 [label="fib(1)"] fib22222 [label="fib(2)"]}
		}
	}	
}