Drew V. McDermott PDDL2.1 - The Art of the Possible? Commentary on Fox and Long. 145-148 2003 20 J. Artif. Intell. Res. (JAIR) http://www.cs.washington.edu/research/jair/abstracts/mcdermott03a.html db/journals/jair/jair20.html#McDermott03