digraph annot {


	gnetlist [shape=box]

	{rank=same pcb gschem spacer1}

	spacer1 [style=invisible]

	foo [shape=box]

	gschem -> gnetlist [label="forward1"]
	pcb -> foo [label="back1"]

	gschem->spacer1->pcb [style=invisible arrowhead=none]

	gnetlist -> pcb [label="forward2"]
	foo -> gschem [label="back2"]
}
