For example, {HEAD ~ the averaging} can be applied to two laterally displacement measurement axes that are substantially parallel to one another to more accurately determine {TAIL ~ an average angular orientation} of the stage 
For example , { HEAD ~ the averaging } can be applied to two laterally displacement measurement axes that are substantially parallel to one another to more accurately determine { TAIL ~ an average angular orientation } of the stage
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH