Each subsystem also includes {HEAD ~ a blocker} coupled to a DA and associated with {TAIL ~ a home directory} 
associated with
Each subsystem also includes { HEAD ~ a blocker } coupled to a DA and associated with { TAIL ~ a home directory }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL