{HEAD ~ A second object} of this invention is to provide {TAIL ~ a method} for controlling an optical disk system 
is to provide
{ HEAD ~ A second object } of this invention is to provide { TAIL ~ a method } for controlling an optical disk system
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH