The purpose of this section is to provide {HEAD ~ an optimal algorithm}, derived from {TAIL ~ its combinatorial set roots} 
derived from
The purpose of this section is to provide { HEAD ~ an optimal algorithm } , derived from { TAIL ~ its combinatorial set roots }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL