A composite number is {HEAD ~ a token number} combined with either an index number or {TAIL ~ length number} 
A composite number is { HEAD ~ a token number } combined with either an index number or { TAIL ~ length number }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL