In a reverse auction, when at least two of the selected bids include different units, or quantities, of the same item, all units of {HEAD ~ all items} are included in {TAIL ~ each candidate allocation} 
In a reverse auction , when at least two of the selected bids include different units , or quantities , of the same item , all units of { HEAD ~ all items } are included in { TAIL ~ each candidate allocation }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL