The ComBack Method Revisited: Caching Strategies and Extension with Delayed Duplicate Detection

  • Sami Evangelista
  • Michael Westergaard
  • Lars M. Kristensen
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5800)


The ComBack method is a memory reduction technique for explicit state space search algorithms. It enhances hash compaction with state reconstruction to resolve hash conflicts on-the-fly thereby ensuring full coverage of the state space. In this paper we provide two means to lower the run-time penalty induced by state reconstructions: a set of strategies to implement the caching method proposed in [20], and an extension through delayed duplicate detection that allows to group reconstructions together to save redundant work.


explicit state model checking state explosion problem state space reduction hash compaction delayed duplicate detection 


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© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • Sami Evangelista
    • 1
  • Michael Westergaard
    • 1
  • Lars M. Kristensen
    • 2
  1. 1.Computer Science DepartmentAarhus UniversityDenmark
  2. 2.Department of Computer EngineeringBergen University CollegeNorway

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