A monitor unit which can monitor {HEAD ~ equivalent operation} of {TAIL ~ the processing sets} can also include the mutex ordering mechanism 
A monitor unit which can monitor { HEAD ~ equivalent operation } of { TAIL ~ the processing sets } can also include the mutex ordering mechanism
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH