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