A read write circuit has {TAIL ~ two data lines} {HEAD ~ each} of which is associated with a read circuit 
of
A read write circuit has { TAIL ~ two data lines } { HEAD ~ each } of which is associated with a read circuit
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH