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International audience; Spatial constraint systems are algebraic structures from concurrent constraint programming to specify spatial and epistemic behavior in multi-agent systems. We shall use spatial constraint systems to give an abstract characterization of the notion of normality in modal logic and to derive right inverse/reverse operators for modal languages. In particular, we shall identify the weakest condition for the existence of right inverses and show that the abstract notion of normality corresponds to the preservation of finite suprema. We shall apply our results to existing modal languages such as the weakest normal modal logic, Hennessy-Milner logic, and linear-time temporal logic. We shall discuss our results in the context of modal concepts such as bisimilarity and inconsistency invariance.

We consider the problem of updating of an agent's knowledge. We propose a formal method of knowledge update on the basis of the semantics of modal logic S5. In our method, an update is specified according to the minimal change on both the agent's actual world and knowledge. We discuss general minimal change properties of knowledge update and show that our knowledge update operator satisfies all the update postulates of Katsuno and Mendelzon. We characterize several specific forms of knowledge update which have important applications in reasoning about change of agents' knowledge. We also examine the persistence property of knowledge and ignorance associated with knowledge update.We then investigate the computational complexity of model checking for knowledge update. We first show that in general the model checking for knowledge update is Σ2P-complete. We then identify a subclass of knowledge update problems that has polynomial time complexity for model checking. We point out that some important knowledge update problems belong to this subclass. We further address another interesting subclass of knowledge update problems for which the complexity of model checking is NP-complete.

For every poset (I; ) and every family .Gi /i2I of groups there exists a family of separable Kripke structures .Ki /i2I on the same set, such thatGi D Aut.Ki / andKi is subalgebra ofKj iff i j , for i; j 2 I . More generally, thiswork is concerned with representations of algebraic categories by means of the category of separable Kripke structures. Consequences thereof are mentioned. Thus, in contrast to the algebraic non-universality of the category of Boolean algebras we conclude the algebraic universality of the category of separable dynamic algebras. Perfect classes of Kripke structures are introduced. JNICT (Programa de Formação e Mobilidade de Recursos Humanos BD1298 Cultural Agreement between Portugal and Czech Republic); Instituto de Telecomunicações.

We propose a way of performing model checking analysis for biological systems. The technics were developed for a CTL* logic built upon Ambient Calculus. We introduce labeled syntax trees for ambient processes and use them as possible worlds in a Kripke structure developed for a propositional branching temporal logic. The accessibility relation over labeled syntax trees is generated by the reduction over corresponding Ambient Calculus processes. Providing the algorithms for calculating the accessibility relation between states, we open the perspective of using model checking algorithms developed for temporal logics in analyzing any phenomena described in Ambient Calculus.

This paper presents some testing approaches based on model checking and using different testing criteria. First, test sets are built from different Kripke structure representations. Second, various rule coverage criteria for transitional, non-deterministic, cell-like P systems, are considered in order to generate adequate test sets. Rule based coverage criteria (simple rule coverage, context-dependent rule coverage and variants) are defined and, for each criterion, a set of LTL (Linear Temporal Logic) formulas is provided. A codification of a P system as a Kripke structure and the sets of LTL properties are used in test generation: for each criterion, test cases are obtained from the counterexamples of the associated LTL formulas, which are automatically generated from the Kripke structure codification of the P system. The method is illustrated with an implementation using a specific model checker, NuSMV. (C) 2010 Elsevier Inc. All rights reserved.