Department of Computer Science, University of New Mexico, Albuquerque, NM 87131, USA. moret@cs.unm.edu|Department of Computer Science, University of New Mexico, Albuquerque, NM 87131, USA. moret@cs.unm.edu|Department of Computer Science, University of New Mexico, Albuquerque, NM 87131, USA. moret@cs.unm.edu|Department of Computer Science, University of New Mexico, Albuquerque, NM 87131, USA. moret@cs.unm.edu