156 views102 votes15 years 5 months ago ICALP 2010»
We investigate the parameterized computational complexity of the satisfiability problem for modal logic and attempt to pinpoint relevant structural parameters which cause the probl...
124 views143 votes15 years 7 months ago AISC 1998»
Effective optimisation techniques can make a dramatic difference in the performance of knowledge representation systems based on expressive description logics. Because of the corre...
113 views108 votes15 years 3 months ago CORR 2008»
It is well-known that modal satisfiability is PSPACE-complete [Lad77]. However, the complexity may decrease if we restrict the set of propositional operators used. Note that there ...
132 views128 votes15 years 5 months ago AAAI 2008»
The study of random instances of NP complete and coNP complete problems has had much impact on our understanding of the nature of hard problems. In this work, we initiate an effor...
130 views102 votes15 years 3 months ago CORR 2006»
There has been a great deal of work on characterizing the complexity of the satisfiability and validity problem for modal logics. In particular, Ladner showed that the consistency...
133 views122 votes15 years 1 months ago FSTTCS 2010»
We study the propositional satisfiability problem (SAT) on classes of CNF formulas (formulas in Conjunctive Normal Form) that obey certain structural restrictions in terms of thei...
A concept language with role intersection and number restriction is defined and its modal equivalent is provided. The main reasoning tasks of satisfiability and subsumption checkin...
120 views121 votes15 years 3 months ago CORR 2008»
Modal logics are widely used in computer science. The complexity of modal satisfiability problems has been investigated since the 1970s, usually proving results on a case-by-case b...
136 views132 votes15 years 14 days ago ENTCS 2010»
We present MLSolver, a tool for solving the satisfiability and validity problems for modal fixpoint logics. The underlying technique is based on characterisations of satisfiabilit...