@article{DelgrandeSchaubTompitsetal.2004,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {On Computing belief change operations using quantifield boolean formulas},
  issn      = {0955-792X},
  year      = {2004},
  abstract  = {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},
  language  = {en}
}
@article{DelgrandeSchaubTompitsetal.2001,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {On computing solutions to belief change scenarios},
  isbn      = {3-540- 42464-4},
  year      = {2001},
  language  = {en}
}
@article{DelgrandeSchaubTompits2006,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {A Preference-Based Framework for Updating logic Programs : preliminary reports},
  year      = {2006},
  language  = {en}
}
@article{DelgrandeSchaubTompits2007,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {A preference-based framework for updating logic programs},
  isbn      = {978-3-540- 72199-4},
  year      = {2007},
  language  = {en}
}
@article{DelgrandeLangSchaub2007,
  author    = {Delgrande, James Patrick and Lang, J{\´e}r{\^o}me and Schaub, Torsten H.},
  title     = {Belief change based on global minimisation},
  year      = {2007},
  language  = {en}
}
@article{DelgrandeLiuSchaubetal.2006,
  author    = {Delgrande, James Patrick and Liu, Daphne H. and Schaub, Torsten H. and Thiele, Sven},
  title     = {COBA 2.0 : a consistency-based belief change system},
  year      = {2006},
  language  = {en}
}
@article{DelgrandeSchaubTompits2006,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {An Extended Query language for action languages (and its application to aggregates and preferences)},
  year      = {2006},
  language  = {en}
}
@article{DelgrandeSchaub2005,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {Expressing default logic variants in default logic},
  issn      = {0955-792X},
  year      = {2005},
  abstract  = {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},
  language  = {en}
}
@article{DelgrandeSchaub2004,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {Two approaches to merging knowledge bases},
  isbn      = {3-540-23242-7},
  year      = {2004},
  language  = {en}
}
@article{DelgrandeSchaubTompits2004,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {Domain-specific preference for causal reasoning and planning},
  isbn      = {1-577-35201-7},
  year      = {2004},
  language  = {en}
}
@article{DelgrandeSchaub2004,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {Consistency-based approaches to merging knowledge based : preliminary report},
  isbn      = {92-990021-0-X},
  year      = {2004},
  language  = {en}
}
@article{DelgrandeSchaubTompitsetal.2004,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans and Wang, Kewen},
  title     = {A classification and survey of preference handling approchaches in nonmonotonic reasoning},
  issn      = {0824-7935},
  year      = {2004},
  abstract  = {In recent years, there has been a large amount of disparate work concerning the representation and reasoning with qualitative preferential information by means of approaches to nonmonotonic reasoning. Given the variety of underlying systems, assumptions, motivations, and intuitions, it is difficult to compare or relate one approach with another. Here, we present an overview and classification for approaches to dealing with preference. A set of criteria for classifying approaches is given, followed by a set of desiderata that an approach might be expected to satisfy. A comprehensive set of approaches is subsequently given and classified with respect to these sets of underlying principles},
  language  = {en}
}
@article{DelgrandeSchaub2004,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {Reasoning with sets of preferences in default logic},
  issn      = {0824-7935},
  year      = {2004},
  abstract  = {We present a general approach for representing and reasoning with sets of defaults in default logic, focusing on reasoning about preferences among sets of defaults. First, we consider how to control the application of a set of defaults so that either all apply (if possible) or none do (if not). From this, an approach to dealing with preferences among sets of default rules is developed. We begin with an ordered default theory, consisting of a standard default theory, but with possible preferences on sets of rules. This theory is transformed into a second, standard default theory wherein the preferences are respected. The approach differs from other work, in that we obtain standard default theories and do not rely on prioritized versions of default logic. In practical terms this means we can immediately use existing default logic theorem provers for an implementation. Also, we directly generate just those extensions containing the most preferred applied rules; in contrast, most previous approaches generate all extensions, then select the most preferred. In a major application of the approach, we show how semimonotonic default theories can be encoded so that reasoning can be carried out at the object level. With this, we can reason about default extensions from within the framework of a standard default logic. Hence one can encode notions such as skeptical and credulous conclusions, and can reason about such conclusions within a single extension},
  language  = {en}
}
@article{DelgrandeSchaubTompits2003,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {A framework for compiling preferences in logic programs},
  year      = {2003},
  language  = {en}
}
@article{DelgrandeSchaub2003,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {Reasoning credulously and skeptically within a single extension},
  year      = {2003},
  language  = {en}
}
@article{DelgrandeSchaub2003,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {On the relation between Reiter{\"i}s default logic and its (major) variants},
  isbn      = {3-540- 409494-5},
  year      = {2003},
  language  = {en}
}
@article{DelgrandeGharibMerceretal.2003,
  author    = {Delgrande, James Patrick and Gharib, Mona and Mercer, Robert E. and Risch, V. and Schaub, Torsten H.},
  title     = {Lukaszewicz-style answer set programming : a preliminary report},
  issn      = {1613-0073},
  year      = {2003},
  language  = {en}
}
@article{DelgrandeSchaub2003,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {A concictency-based paradigm for belief change},
  issn      = {0004-3702},
  year      = {2003},
  language  = {en}
}
@article{DelgrandeSchaubTompitsetal.2002,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans and Wang, Kewen},
  title     = {Towards a classification of preference handling approaches in nonmonotonic reasoning},
  isbn      = {1-577-35166-5},
  year      = {2002},
  language  = {en}
}
@article{DelgrandeSchaub2002,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {Reasoning credulously and skeptically within a single extension},
  year      = {2002},
  language  = {en}
}