Bidding languages represent a mean for the bidder to express a value for a certain set of goods.
Typically, bidding languages in SATS contain an iterator that defines by what logic a bidder provides bids when he
is asked for a new bid.
For example, we can ask a bidder to provide XOR bids, starting at the smallest bundle and increasing the size the
more bids we ask for (see
IncreasingSizeOrderedXOR).
Another example is to get (parametrized) random bids with the
SizeBasedUniqueRandomXOR
A famous example of a more domain-specific iterator is described in CATS by Leyton-Brown et al. (2000).
The part that makes the domain most interesting is the algorithm on how the bidders bid based on some parameters.
If trying to imitate a bidding behavior is the focus in a certain model, such an iterator is essential to the model.
On the other hand, if you are less interested in a specific bidding behavior, but are more interested in getting
the "most profitable" bids of the bidder in a certain model, you can find those by using a demand query
(see
DemandQuery.