A message is output when the degree of {HEAD ~ the wear position deviates} from {TAIL ~ the degree} of the reference position by more than the degree of wear permissible 
from
A message is output when the degree of { HEAD ~ the wear position deviates } from { TAIL ~ the degree } of the reference position by more than the degree of wear permissible
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH