{TAIL ~ The portion} of {HEAD ~ this lock range} in which the width of the lock range decreases is positively utilized 
{ TAIL ~ The portion } of { HEAD ~ this lock range } in which the width of the lock range decreases is positively utilized
TAIL 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