{TAIL ~ Outputs} of the first and the second comparator groups 10a and {HEAD ~ 10b} are supplied to an encoding circuit 11 
{ TAIL ~ Outputs } of the first and the second comparator groups 10a and { HEAD ~ 10b } are supplied to an encoding circuit 11
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH