If {HEAD ~ exposure} of {TAIL ~ all the pattern portions} were not successfully completed, processing returns to the step at which the error occurred and repeated 
of
If { HEAD ~ exposure } of { TAIL ~ all the pattern portions } were not successfully completed , processing returns to the step at which the error occurred and repeated
OTH HEAD HEAD HEAD HEAD HEAD REL 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