Arbiter 16 receives requests for access from {HEAD ~ any} of {TAIL ~ a number} of requesters 
of
Arbiter 16 receives requests for access from { HEAD ~ any } of { TAIL ~ a number } of requesters
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH