digraph target{
	rankdir=LR
	concrete [label="terminal in the\nconcrete model\nattr: pcb_pinnum\nnattr: pinnum\nattr: name" shape=box]
	target_pcb [label="engine plugin:\ntarget_pcb"]
	abstract [label="port in the\nabstract model\nattr: display/name" shape="box"]
	export_tedax [label="export plugin:\nexport_tedax"]
	netlist [label="netlist output:\nfoo.tdx" shape="box"]

	concrete -> target_pcb
	target_pcb -> abstract
	abstract -> export_tedax
	export_tedax -> netlist
}