digraph graph_29_01
{
	# 'one' is a node name, not a subgraph name.

	one { two -> three }

	# 'cluster_four' is a node name, not a subgraph name.

	cluster_four { five -> six }

	# 'cluster_seven' is a subgraph name, not a node name.

	subgraph cluster_seven { label = "\G" eight -> nine }
}