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