, Volume 64, Issue 1, pp 38–55 | Cite as

Parameterized Modal Satisfiability



We investigate the parameterized computational complexity of the satisfiability problem for modal logic and attempt to pinpoint relevant structural parameters which cause the problem’s combinatorial explosion, beyond the number of propositional variables v. To this end we study the modality depth, a natural measure which has appeared in the literature, and show that, even though modal satisfiability parameterized by v and the modality depth is FPT, the running time’s dependence on the parameters is a tower of exponentials (unless P = NP). To overcome this limitation we propose possible alternative parameters, namely diamond dimension and modal width. We show fixed-parameter tractability results using these measures where the exponential dependence on the parameters is much milder (doubly and singly exponential respectively) than in the case of modality depth thus leading to FPT algorithms for modal satisfiability with much more reasonable running times. We also give lower bound arguments which prove that our algorithms cannot be improved significantly unless the Exponential Time Hypothesis fails.


Modal logic Parameterized complexity Satisfiability problems 


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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Antonis Achilleos
    • 1
  • Michael Lampis
    • 1
  • Valia Mitsou
    • 1
  1. 1.Computer Science DepartmentGraduate Center, City University of New YorkNew YorkUSA

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