{HEAD ~ The superfinishing wheel} of the second wheel head sequentially superfinishes {TAIL ~ the object portions} which have been ground by means of the grinding wheel, while the second wheel head is moving toward the home position of the first wheel head, and in parallel with grinding which is performed by means of the grinding wheel 
sequentially superfinishes
{ HEAD ~ The superfinishing wheel } of the second wheel head sequentially superfinishes { TAIL ~ the object portions } which have been ground by means of the grinding wheel , while the second wheel head is moving toward the home position of the first wheel head , and in parallel with grinding which is performed by means of the grinding wheel
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL REL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH