In {TAIL ~ this manner}, fair arbitration is assured for other CPUs contending for control of {HEAD ~ the system bus} 
In { TAIL ~ this manner } , fair arbitration is assured for other CPUs contending for control of { HEAD ~ the system bus }
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD