{TAIL ~ input and local fields} that store {HEAD ~ knowledge variables} that operate said output knowledge variable; and 
{ TAIL ~ input and local fields } that store { HEAD ~ knowledge variables } that operate said output knowledge variable ; and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH