In this event, since {HEAD ~ RX} is {TAIL ~ a read signal} read by a head B in FIG 15, and RZ is a read signal read by a head F, the above equation may be modified to: 
is
In this event , since { HEAD ~ RX } is { TAIL ~ a read signal } read by a head B in FIG 15 , and RZ is a read signal read by a head F , the above equation may be modified to :
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH