Winner Determination in Combinatorial Auctions with Logic-based Bidding Languages Joel Uckelman, Ulle Endriss Abstract: We propose the use of logic-based preference representation languages based on weighted propositional formulas for specifying bids in a combinatorial auction. We then develop several heuristics for a branch-and-bound search algorithm for determining the winning bids in this framework and report on their empirical performance. The logic-based approach is attractive due to its high degree of flexibility in designing a range of different bidding languages within a single conceptual framework.