The RA provides a subsystem with a mechanism for sending read and write requests to {HEAD ~ the DA} of {TAIL ~ another subsystem} 
of
The RA provides a subsystem with a mechanism for sending read and write requests to { HEAD ~ the DA } of { TAIL ~ another subsystem }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL