{HEAD ~ The following detailed description} is of {TAIL ~ the best currently contemplated modes} of carrying out the invention 
is of
{ HEAD ~ The following detailed description } is of { TAIL ~ the best currently contemplated modes } of carrying out the invention
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH