When the amount of compensation in the fine displacing drive unit exceeds a predetermined value, the Y axis drive system is actuated so that {HEAD ~ the amount} of compensation by the fine displacing drive unit lies within {TAIL ~ a predetermined range} 
lies within
When the amount of compensation in the fine displacing drive unit exceeds a predetermined value , the Y axis drive system is actuated so that { HEAD ~ the amount } of compensation by the fine displacing drive unit lies within { TAIL ~ a predetermined range }
OTH OTH OTH OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL