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