Solving Qualitative Constraints Involving Landmarks

  • Weiming Liu
  • Shengsheng Wang
  • Sanjiang Li
  • Dayou Liu
Part of the Lecture Notes in Computer Science book series (LNCS, volume 6876)


Consistency checking plays a central role in qualitative spatial and temporal reasoning. Given a set of variables V, and a set of constraints Γ taken from a qualitative calculus (e.g. the Interval Algebra (IA) or RCC-8), the aim is to decide if Γ is consistent. The consistency problem has been investigated extensively in the literature. Practical applications e.g. urban planning often impose, in addition to those between undetermined entities (variables), constraints between determined entities (constants or landmarks) and variables. This paper introduces this as a new class of qualitative constraint satisfaction problems, and investigates the new consistency problem in several well-known qualitative calculi, e.g. IA, RCC-5, and RCC-8. We show that the usual local consistency checking algorithm works for IA but fails in RCC-5 and RCC-8. We further show that, if the landmarks are represented by polygons, then the new consistency problem of RCC-5 is tractable but that of RCC-8 is NP-complete.


Control Point Tangential Point Propositional Variable Basic Network Constraint Network 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2011

Authors and Affiliations

  • Weiming Liu
    • 1
  • Shengsheng Wang
    • 2
  • Sanjiang Li
    • 1
  • Dayou Liu
    • 2
  1. 1.Centre for Quantum Computation and Intelligent Systems, Faculty of Engineering and Information TechnologyUniversity of TechnologySydneyAustralia
  2. 2.College of Computer Science and TechnologyJilin UniversityChangchunChina

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