The processing unit receives {HEAD ~ a query} for {TAIL ~ an item} and uses the features index to determine search results including the item, such as a location and a time of the item 
for
The processing unit receives { HEAD ~ a query } for { TAIL ~ an item } and uses the features index to determine search results including the item , such as a location and a time of the item
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH