Dokument-ID Dokumenttyp Verfasser/Autoren Herausgeber Haupttitel Abstract Auflage Verlagsort Verlag Erscheinungsjahr Seitenzahl Schriftenreihe Titel Schriftenreihe Bandzahl ISBN Quelle der Hochschulschrift Konferenzname Quelle:Titel Quelle:Jahrgang Quelle:Heftnummer Quelle:Erste Seite Quelle:Letzte Seite URN DOI Abteilungen OPUS4-15225 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H.; Tompits, Hans; Woltran, Stefan On Computing belief change operations using quantifield boolean formulas In this paper, we show how an approach to belief revision and belief contraction can be axiomatized by means of quantified Boolean formulas. Specifically, we consider the approach of belief change scenarios, a general framework that has been introduced for expressing different forms of belief change. The essential idea is that for a belief change scenario (K, R, C), the set of formulas K, representing the knowledge base, is modified so that the sets of formulas R and C are respectively true in, and consistent with the result. By restricting the form of a belief change scenario, one obtains specific belief change operators including belief revision, contraction, update, and merging. For both the general approach and for specific operators, we give a quantified Boolean formula such that satisfying truth assignments to the free variables correspond to belief change extensions in the original approach. Hence, we reduce the problem of determining the results of a belief change operation to that of satisfiability. This approach has several benefits. First, it furnishes an axiomatic specification of belief change with respect to belief change scenarios. This then leads to further insight into the belief change framework. Second, this axiomatization allows us to identify strict complexity bounds for the considered reasoning tasks. Third, we have implemented these different forms of belief change by means of existing solvers for quantified Boolean formulas. As well, it appears that this approach may be straightforwardly applied to other specific approaches to belief change 2004 Institut für Informatik und Computational Science OPUS4-18140 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H.; Tompits, Hans; Woltran, Stefan On computing solutions to belief change scenarios 2001 3-540- 42464-4 Institut für Informatik und Computational Science OPUS4-11605 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H.; Tompits, Hans A Preference-Based Framework for Updating logic Programs : preliminary reports 2006 Institut für Informatik und Computational Science OPUS4-12420 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H.; Tompits, Hans A preference-based framework for updating logic programs 2007 978-3-540- 72199-4 Institut für Informatik und Computational Science OPUS4-12466 Wissenschaftlicher Artikel Delgrande, James Patrick; Lang, Jérôme; Schaub, Torsten H. Belief change based on global minimisation 2007 Institut für Informatik und Computational Science OPUS4-12328 Wissenschaftlicher Artikel Delgrande, James Patrick; Liu, Daphne H.; Schaub, Torsten H.; Thiele, Sven COBA 2.0 : a consistency-based belief change system 2006 Institut für Informatik und Computational Science OPUS4-12329 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H.; Tompits, Hans An Extended Query language for action languages (and its application to aggregates and preferences) 2006 Institut für Informatik und Computational Science OPUS4-13558 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H. Expressing default logic variants in default logic Reiter's default logic is one of the best known and most studied of the approaches to nonmonotonic reasoning. Several variants of default logic have subsequently been proposed to give systems with properties differing from the original. In this paper, we examine the relationship between default logic and its major variants. We accomplish this by translating a default theory under a variant interpretation into a second default theory, under the original Reiter semantics, wherein the variant interpretation is respected. That is, in each case we show that, given an extension of a translated theory, one may extract an extension of the original variant default logic theory. We show how constrained, rational, justified, and cumulative default logic can be expressed in Reiter's default logic. As well, we show how Reiter's default logic can be expressed in rational default logic. From this, we suggest that any such variant can be similarly treated. Consequently, we provide a unification of default logics, showing how the original formulation of default logic may express its variants. Moreover, the translations clearly express the relationships between alternative approaches to default logic. The translations themselves are shown to generally have good properties. Thus, in at least a theoretical sense, we show that these variants are in a sense superfluous, in that for any of these variants of default logic, we can exactly mimic the behaviour of a variant in standard default logic. As well, the translations lend insight into means of classifying the expressive power of default logic variants; specifically we suggest that the property of semi-monotonicity represents a division with respect to expressibility, whereas regularity and cumulativity do not 2005 Institut für Informatik und Computational Science OPUS4-14296 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H. Two approaches to merging knowledge bases 2004 3-540-23242-7 Institut für Informatik und Computational Science OPUS4-14301 Wissenschaftlicher Artikel Delgrande, James Patrick; Schaub, Torsten H.; Tompits, Hans Domain-specific preference for causal reasoning and planning 2004 1-577-35201-7 Institut für Informatik und Computational Science