REFIX rdfs:<http://www.w3.org/2000/01/rdf-schema#>
PREFIX : <http://admin/delivery.owl#>

SELECT ?c0 ?c1 ?c2 ?c3 ?c4
WHERE
{
	?c0 a :MediaProducer.
	?c0 ?p1 ?c1. ?c1 a :DeliveryPartner.
	OPTIONAL{?c1 ?p2 ?c2. ?c2 a :DeliveryPoint.}
	OPTIONAL{?c2 ?p3 ?c3. ?c3 a :Channel.}
}
ORDER BY ?c0 ?c1 ?c2 ?c3 ?c4
LIMIT 50