{TAIL ~ The pattern} is then measured by {HEAD ~ a parallel optical processing system} 8, such as is employed in a vidicon system 
{ TAIL ~ The pattern } is then measured by { HEAD ~ a parallel optical processing system } 8 , such as is employed in a vidicon system
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH