Acknowledgments

We appreciate the support of the National Science Foundation and the Royal Swedish Academy of Engineering Sciences, as well as the feedback of Sven Koenig, Shlomo Zilberstein, Paul Batchis, Bob Givan, Hector Geffner and other participants who contributed to the design of the competition. JAIR editor David Smith and his anonymous reviewers provided invaluable insights on the document that we tried to reflect in this final manuscript.

This material is based upon work supported by the National Science Foundation under Grant No. 0315909 and the Royal Swedish Academy of Engineering Sciences (IVA) with grants from the Hans Werthén fund. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation or IVA.