comparing {HEAD ~ the actual stage velocity} against {TAIL ~ a pre set stage velocity limit} above which continuous transfer of the pattern portions is impossible, and against a pre set specified stage velocity less than but near the stage velocity limit 
against
comparing { HEAD ~ the actual stage velocity } against { TAIL ~ a pre set stage velocity limit } above which continuous transfer of the pattern portions is impossible , and against a pre set specified stage velocity less than but near the stage velocity limit
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL 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 OTH OTH