Methods and systems for a topology service providing {HEAD ~ an interface} for specifying a topology and answering {TAIL ~ queries} regarding the topology 
for answering
Methods and systems for a topology service providing { HEAD ~ an interface } for specifying a topology and answering { TAIL ~ queries } regarding the topology
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH