In {TAIL ~ a multi unit combinatorial auction}, {HEAD ~ reverse auction}, or exchange, a number of bids can be received, with each bid including one or more items and for each item a desired quantity thereof 
In
In { TAIL ~ a multi unit combinatorial auction } , { HEAD ~ reverse auction } , or exchange , a number of bids can be received , with each bid including one or more items and for each item a desired quantity thereof
REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD 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