{TAIL ~ The method} 9, further comprising resetting the reference position to zero in response to an input command from {HEAD ~ an operator} of the tool 
{ TAIL ~ The method } 9 , further comprising resetting the reference position to zero in response to an input command from { HEAD ~ an operator } of the tool
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH