{HEAD ~ The invention} is {TAIL ~ an automotive catalyst system} for treating internal combustion engine exhaust gases 
is
{ HEAD ~ The invention } is { TAIL ~ an automotive catalyst system } for treating internal combustion engine exhaust gases
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH