Characterizing Definability in Decidable Fixpoint Logics
نویسندگان
چکیده
We look at characterizing which formulas are expressible in rich decidable logics such as guarded fixpoint logic, unary negation fixpoint logic, and guarded negation fixpoint logic. We consider semantic characterizations of definability, as well as effective characterizations. Our algorithms revolve around a finer analysis of the tree-model property and a refinement of the method of moving back-and-forth between relational logics and logics over trees.
منابع مشابه
Fixpoint Extensions of Temporal Description Logics
In this paper we introduce a decidable fixpoint extension of temporal Description Logics. We exploit the decidability results obtained for various monodic extensions of Description Logics to obtain decidability and tight complexity results for temporal fixpoint extensions of these Description Logics and more generally for the decidable monodic fragments of first order logic.
متن کاملFixpoints in Temporal Description Logics
We study a decidable fixpoint extension of temporal description logics. To this end we employ and extend decidability results obtained for various temporally first-order monodic extensions of (firstorder) description logics. Using these techniques we obtain decidability and tight complexity results for various fixpoint extensions of temporal description logics.
متن کاملInterpolation and Beth Definability over the Minimal Logic
Extensions of the Johansson minimal logic J are investigated. It is proved that the weak interpolation property WIP is decidable over J. Well-composed logics with the Graig interpolation property CIP, restricted interpolation property IPR and projective Beth property PBP are fully described. It is proved that there are only finitely many well-composed logics with CIP, IPR or PBP; for any well-c...
متن کاملUniform Interpolation for Coalgebraic Fixpoint Logic
We use the connection between automata and logic to prove that a wide class of coalgebraic fixpoint logics enjoys uniform interpolation. To this aim, first we generalize one of the central results in coalgebraic automata theory, namely closure under projection, which is known to hold for weak-pullback preserving functors, to a more general class of functors, i.e.; functors with quasi-functorial...
متن کاملCharacterizing Frame Definability in Team Semantics via the Universal Modality
Let ML( u) denote the fragment of modal logic extended with the universal modality in which the universal modality occurs only positively. We characterize the definability of ML( u) in the spirit of the well-known Goldblatt-Thomason-Theorem. We show that an elementary class F of Kripke frames is definable in ML( u) if and only if F is closed under taking generated subframes and bounded morphic ...
متن کامل