A number of unique combinations of {HEAD ~ bids} can be formed from the received bids, and the one combination of {TAIL ~ bids} which represents the best value in terms of an auction setting, a reverse auction setting and an exchange setting can be determined 
A number of unique combinations of { HEAD ~ bids } can be formed from the received bids , and the one combination of { TAIL ~ bids } which represents the best value in terms of an auction setting , a reverse auction setting and an exchange setting can be determined
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH