{HEAD ~ The distance} of each focus point from {TAIL ~ the best fit surface} is then calculated and the largest distance is compared to a predetermined value 
from
{ HEAD ~ The distance } of each focus point from { TAIL ~ the best fit surface } is then calculated and the largest distance is compared to a predetermined value
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH