strict digraph graph_09
{
	# Node to node.

	a [color = red   style = filled]
	b [color = green style = filled]

	a -> b

	# Node to subgraph.

	c [color = blue      style = filled]
	d [color = orange    style = filled]
	e [color = goldenrod style = filled]

	c -> { d e }

	# Subgraph to node.

	f [color = coral     style = filled]
	g [color = salmon    style = filled]
	h [color = mistyrose style = filled]

	{ f g } -> h

	# Subgraph to subgraph.

	i [color = lemonchiffon style = filled]
	j [color = yellow       style = filled]
	k [color = olivedrab    style = filled]
	l [color = lime         style = filled]

	{ i j } -> { k l }

	# Standalone clusters.

	x
	y
	z
}