Eq. 8 indicates the values A to {TAIL ~ Z} and AA to {HEAD ~ AE} 
Eq . 8 indicates the values A to { TAIL ~ Z } and AA to { HEAD ~ AE }
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH HEAD HEAD HEAD HEAD HEAD