{TAIL ~ A server} receives an interaction history comprising {HEAD ~ a set} of one to one interactions between a first user and other users 
{ TAIL ~ A server } receives an interaction history comprising { HEAD ~ a set } of one to one interactions between a first user and other users
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH