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