In addition, {TAIL ~ a third subsystem} and fourth subsystem have {HEAD ~ S copies} of the data line 
In addition , { TAIL ~ a third subsystem } and fourth subsystem have { HEAD ~ S copies } of the data line
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH