@article{CabalarFandinnoSchaubetal.2019,
  author    = {Cabalar, Pedro and Fandinno, Jorge and Schaub, Torsten H. and Schellhorn, Sebastian},
  title     = {Gelfond-Zhang aggregates as propositional formulas},
  series = {Artificial intelligence},
  volume    = {274},
  journal   = {Artificial intelligence},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0004-3702},
  doi       = {10.1016/j.artint.2018.10.007},
  pages     = {26 -- 43},
  year      = {2019},
  abstract  = {Answer Set Programming (ASP) has become a popular and widespread paradigm for practical Knowledge Representation thanks to its expressiveness and the available enhancements of its input language. One of such enhancements is the use of aggregates, for which different semantic proposals have been made. In this paper, we show that any ASP aggregate interpreted under Gelfond and Zhang's (GZ) semantics can be replaced (under strong equivalence) by a propositional formula. Restricted to the original GZ syntax, the resulting formula is reducible to a disjunction of conjunctions of literals but the formulation is still applicable even when the syntax is extended to allow for arbitrary formulas (including nested aggregates) in the condition. Once GZ-aggregates are represented as formulas, we establish a formal comparison (in terms of the logic of Here-and-There) to Ferraris' (F) aggregates, which are defined by a different formula translation involving nested implications. In particular, we prove that if we replace an F-aggregate by a GZ-aggregate in a rule head, we do not lose answer sets (although more can be gained). This extends the previously known result that the opposite happens in rule bodies, i.e., replacing a GZ-aggregate by an F-aggregate in the body may yield more answer sets. Finally, we characterize a class of aggregates for which GZ- and F-semantics coincide.},
  language  = {en}
}
@article{SarsakovSchaubTompitsetal.2004,
  author    = {Sarsakov, Vladimir and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {A compiler for nested logic programming},
  isbn      = {3-540- 20721-x},
  year      = {2004},
  language  = {en}
}
@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{PearceSarsakovSchaubetal.2002,
  author    = {Pearce, David and Sarsakov, Vladimir and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {A polynomial translation of logic programs with nested expressions into disjunctive logic programs},
  isbn      = {3-540-43930-7},
  year      = {2002},
  language  = {en}
}
@article{BesnardSchaubTompitsetal.2002,
  author    = {Besnard, Philippe and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {Paraconsistent reasoning via quantified boolean formulas},
  isbn      = {3-540-44190-5},
  year      = {2002},
  language  = {en}
}
@article{BrainGebserPuehreretal.2007,
  author    = {Brain, Martin and Gebser, Martin and P{\"u}hrer, J{\"o}rg and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {"That is illogical, Captain!" : the debugging support tool spock for answer-set programs ; system description},
  year      = {2007},
  language  = {en}
}
@article{PearceSarsakovSchaubetal.2002,
  author    = {Pearce, David and Sarsakov, Vladimir and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {A polynomial translation of logic programs with nested expressions into disjunctive logic programs : preliminary report},
  year      = {2002},
  language  = {en}
}
@article{SchaubWoltran2018,
  author    = {Schaub, Torsten H. and Woltran, Stefan},
  title     = {Answer set programming unleashed!},
  series = {K{\"u}nstliche Intelligenz},
  volume    = {32},
  journal   = {K{\"u}nstliche Intelligenz},
  number    = {2-3},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0933-1875},
  doi       = {10.1007/s13218-018-0550-z},
  pages     = {105 -- 108},
  year      = {2018},
  abstract  = {Answer Set Programming faces an increasing popularity for problem solving in various domains. While its modeling language allows us to express many complex problems in an easy way, its solving technology enables their effective resolution. In what follows, we detail some of the key factors of its success. Answer Set Programming [ASP; Brewka et al. Commun ACM 54(12):92-103, (2011)] is seeing a rapid proliferation in academia and industry due to its easy and flexible way to model and solve knowledge-intense combinatorial (optimization) problems. To this end, ASP offers a high-level modeling language paired with high-performance solving technology. As a result, ASP systems provide out-off-the-box, general-purpose search engines that allow for enumerating (optimal) solutions. They are represented as answer sets, each being a set of atoms representing a solution. The declarative approach of ASP allows a user to concentrate on a problem's specification rather than the computational means to solve it. This makes ASP a prime candidate for rapid prototyping and an attractive tool for teaching key AI techniques since complex problems can be expressed in a succinct and elaboration tolerant way. This is eased by the tuning of ASP's modeling language to knowledge representation and reasoning (KRR). The resulting impact is nicely reflected by a growing range of successful applications of ASP [Erdem et al. AI Mag 37(3):53-68, 2016; Falkner et al. Industrial applications of answer set programming. K++nstliche Intelligenz (2018)]},
  language  = {en}
}
@misc{SchaubWoltran2018,
  author    = {Schaub, Torsten H. and Woltran, Stefan},
  title     = {Special issue on answer set programming},
  series = {K{\"u}nstliche Intelligenz},
  volume    = {32},
  journal   = {K{\"u}nstliche Intelligenz},
  number    = {2-3},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0933-1875},
  doi       = {10.1007/s13218-018-0554-8},
  pages     = {101 -- 103},
  year      = {2018},
  language  = {en}
}
@article{BesnardSchaubTompitsetal.2003,
  author    = {Besnard, Philippe and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {Paraconsistent reasoning via quantified boolean formulas : Part II: Circumscribing inconsistent theories},
  isbn      = {3-540- 409494-5},
  year      = {2003},
  language  = {en}
}
@article{DelgrandeSchaubTompitsetal.2013,
  author    = {Delgrande, James and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {A model-theoretic approach to belief change in answer set programming},
  series = {ACM transactions on computational logic},
  volume    = {14},
  journal   = {ACM transactions on computational logic},
  number    = {2},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  issn      = {1529-3785},
  doi       = {10.1145/2480759.2480766},
  pages     = {46},
  year      = {2013},
  abstract  = {We address the problem of belief change in (nonmonotonic) logic programming under answer set semantics. Our formal techniques are analogous to those of distance-based belief revision in propositional logic. In particular, we build upon the model theory of logic programs furnished by SE interpretations, where an SE interpretation is a model of a logic program in the same way that a classical interpretation is a model of a propositional formula. Hence we extend techniques from the area of belief revision based on distance between models to belief change in logic programs. We first consider belief revision: for logic programs P and Q, the goal is to determine a program R that corresponds to the revision of P by Q, denoted P * Q. We investigate several operators, including (logic program) expansion and two revision operators based on the distance between the SE models of logic programs. It proves to be the case that expansion is an interesting operator in its own right, unlike in classical belief revision where it is relatively uninteresting. Expansion and revision are shown to satisfy a suite of interesting properties; in particular, our revision operators satisfy all or nearly all of the AGM postulates for revision. We next consider approaches for merging a set of logic programs, P-1,...,P-n. Again, our formal techniques are based on notions of relative distance between the SE models of the logic programs. Two approaches are examined. The first informally selects for each program P-i those models of P-i that vary the least from models of the other programs. The second approach informally selects those models of a program P-0 that are closest to the models of programs P-1,...,P-n. In this case, P-0 can be thought of as a set of database integrity constraints. We examine these operators with regards to how they satisfy relevant postulate sets. Last, we present encodings for computing the revision as well as the merging of logic programs within the same logic programming framework. This gives rise to a direct implementation of our approach in terms of off-the-shelf answer set solvers. These encodings also reflect the fact that our change operators do not increase the complexity of the base formalism.},
  language  = {en}
}
@article{BrainGebserPuehreretal.2007,
  author    = {Brain, Martin and Gebser, Martin and P{\"u}hrer, J{\"o}rg and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {Debugging ASP programs by means of ASP},
  isbn      = {978-3-540- 72199-4},
  year      = {2007},
  language  = {en}
}
@article{GebserSchaubTompitsetal.2007,
  author    = {Gebser, Martin and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan},
  title     = {Alternative characterizations for program equivalence under aswer-set semantics : a preliminary report},
  year      = {2007},
  language  = {en}
}
@misc{SchaepersNiemuellerLakemeyeretal.2018,
  author    = {Sch{\"a}pers, Bj{\"o}rn and Niemueller, Tim and Lakemeyer, Gerhard and Gebser, Martin and Schaub, Torsten H.},
  title     = {ASP-Based Time-Bounded Planning for Logistics Robots},
  series = {Twenty-Eighth International Conference on Automated Planning and Scheduling (ICAPS 2018)},
  journal   = {Twenty-Eighth International Conference on Automated Planning and Scheduling (ICAPS 2018)},
  publisher = {ASSOC Association for the Advancement of Artificial Intelligence},
  address   = {Palo Alto},
  issn      = {2334-0835},
  pages     = {509 -- 517},
  year      = {2018},
  abstract  = {Manufacturing industries are undergoing a major paradigm shift towards more autonomy. Automated planning and scheduling then becomes a necessity. The Planning and Execution Competition for Logistics Robots in Simulation held at ICAPS is based on this scenario and provides an interesting testbed. However, the posed problem is challenging as also demonstrated by the somewhat weak results in 2017. The domain requires temporal reasoning and dealing with uncertainty. We propose a novel planning system based on Answer Set Programming and the Clingo solver to tackle these problems and incentivize robot cooperation. Our results show a significant performance improvement, both, in terms of lowering computational requirements and better game metrics.},
  language  = {en}
}
@article{GrellSchaubSelbig2006,
  author    = {Grell, Susanne and Schaub, Torsten H. and Selbig, Joachim},
  title     = {Modelling biological networks by action languages via set programming},
  issn      = {0302-9743},
  doi       = {10.1007/11799573},
  year      = {2006},
  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{GressmannJanhunenMerceretal.2006,
  author    = {Gressmann, Jean and Janhunen, Tomi and Mercer, Robert E. and Schaub, Torsten H. and Thiele, Sven and Tichy, Richard},
  title     = {On probing and multi-threading in platypus},
  year      = {2006},
  language  = {en}
}
@article{AngerGebserSchaub2006,
  author    = {Anger, Christian and Gebser, Martin and Schaub, Torsten H.},
  title     = {Approaching the core of unfounded sets},
  year      = {2006},
  language  = {en}
}
@article{GerbserSchaub2006,
  author    = {Gerbser, Martin and Schaub, Torsten H.},
  title     = {Tableau calculi for answer set programming},
  issn      = {0302-9743},
  doi       = {10.1007/11799573},
  year      = {2006},
  language  = {en}
}
@article{AngerGebserJanhunenetal.2006,
  author    = {Anger, Christian and Gebser, Martin and Janhunen, Tomi and Schaub, Torsten H.},
  title     = {What's a head without a body?},
  year      = {2006},
  language  = {en}
}
@article{GerbserSchaub2006,
  author    = {Gerbser, Martin and Schaub, Torsten H.},
  title     = {Characterizing (ASP) inferences by unit propagation},
  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{MileoSchaub2007,
  author    = {Mileo, Alessandra and Schaub, Torsten H.},
  title     = {Qualitative constraint enforcement in advanced policy specification},
  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{KonczakLinkeSchaub2006,
  author    = {Konczak, Kathrin and Linke, Thomas and Schaub, Torsten H.},
  title     = {Graphs and colorings for answer set programming},
  issn      = {1471-0684},
  doi       = {10.1017/S1471068405002528},
  year      = {2006},
  abstract  = {We investigate the usage of rule dependency graphs and their colorings for characterizing and computing answer sets of logic programs. This approach provides us with insights into the interplay between rules when inducing answer sets. We start with different characterizations of answer sets in terms of totally colored dependency graphs that differ ill graph-theoretical aspects. We then develop a series of operational characterizations of answer sets in terms of operators on partial colorings. In analogy to the notion of a derivation in proof theory, our operational characterizations are expressed as (non-deterministically formed) sequences of colorings, turning an uncolored graph into a totally colored one. In this way, we obtain an operational framework in which different combinations of operators result in different formal properties. Among others, we identify the basic strategy employed by the noMoRe system and justify its algorithmic approach. Furthermore, we distinguish operations corresponding to Fitting's operator as well as to well-founded semantics},
  language  = {en}
}
@article{GebserSchaubThiele2007,
  author    = {Gebser, Martin and Schaub, Torsten H. and Thiele, Sven},
  title     = {GrinGo : a new grounder for answer set programming},
  isbn      = {978-3-540- 72199-4},
  year      = {2007},
  language  = {en}
}
@article{KonczakLinkeSchaub2004,
  author    = {Konczak, Kathrin and Linke, Thomas and Schaub, Torsten H.},
  title     = {Graphs and cologings for answer set programming : adridged report},
  isbn      = {3-540- 20721-x},
  year      = {2004},
  language  = {en}
}
@article{BoeselLinkeSchaub2004,
  author    = {Boesel, Andreas and Linke, Thomas and Schaub, Torsten H.},
  title     = {Profiling answer set programming : the visualization component of the noMoRe System},
  isbn      = {3-540-23242-7},
  year      = {2004},
  language  = {en}
}
@article{GressmannJanhunenMerceretal.2006,
  author    = {Gressmann, Jean and Janhunen, Tomi and Mercer, Robert E. and Schaub, Torsten H. and Thiele, Sven and Tichy, Richard},
  title     = {On probing and multi-threading in platypus},
  year      = {2006},
  language  = {en}
}
@article{MileoSchaub2006,
  author    = {Mileo, Alessandra and Schaub, Torsten H.},
  title     = {Extending ordered disjunctions for policy enforcement : preliminary report},
  year      = {2006},
  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{AngerGebserLinkeetal.2005,
  author    = {Anger, Christian and Gebser, Martin and Linke, Thomas and Neumann, Andre and Schaub, Torsten H.},
  title     = {The nomore++ approach to answer set solving},
  year      = {2005},
  language  = {en}
}
@article{GressmannJanhunenMerceretal.2005,
  author    = {Gressmann, Jean and Janhunen, Tomi and Mercer, Robert E. and Schaub, Torsten H. and Thiele, Sven and Tichy, Richard},
  title     = {Platypus : a platform for distributed answer set solving},
  year      = {2005},
  language  = {en}
}
@article{AngerGebserLinkeetal.2005,
  author    = {Anger, Christian and Gebser, Martin and Linke, Thomas and Neumann, Andre and Schaub, Torsten H.},
  title     = {The nomore++ approach to answer set solving},
  year      = {2005},
  language  = {en}
}
@article{GrellKonczakSchaub2005,
  author    = {Grell, Susanne and Konczak, Kathrin and Schaub, Torsten H.},
  title     = {nomore) : a system for computing preferred Answer Sets},
  issn      = {0302-9743},
  year      = {2005},
  language  = {en}
}
@article{AngerKonczakLinkeetal.2005,
  author    = {Anger, Christian and Konczak, Kathrin and Linke, Thomas and Schaub, Torsten H.},
  title     = {A Glimpse of Answer Set Programming},
  issn      = {0170-4516},
  year      = {2005},
  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{GebserLiuNamasivayametal.2007,
  author    = {Gebser, Martin and Liu, Lengning and Namasivayam, Gayathri and Neumann, Andr{\´e} and Schaub, Torsten H. and Truszczynski, Miroslaw},
  title     = {The first answer set programming system competition},
  isbn      = {978-3-540- 72199-4},
  year      = {2007},
  language  = {en}
}
@article{BorchertAngerSchaubetal.2004,
  author    = {Borchert, P. and Anger, Christian and Schaub, Torsten H. and Truszczynski, M.},
  title     = {Towards systematic benchmarking in answer set programming : the dagstuhl initiative},
  isbn      = {3-540- 20721-x},
  year      = {2004},
  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{FloeterSelbigSchaub2004,
  author    = {Fl{\"o}ter, Andr{\´e} and Selbig, Joachim and Schaub, Torsten H.},
  title     = {Finding metabolic pathways in decision forests},
  isbn      = {3-540-23221-4},
  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{FloeterNicolasSchaubetal.2004,
  author    = {Fl{\"o}ter, Andr{\´e} and Nicolas, Jacques and Schaub, Torsten H. and Selbig, Joachim},
  title     = {Threshold extraction in metabolite concentration data},
  year      = {2004},
  abstract  = {Motivation: Continued development of analytical techniques based on gas chromatography and mass spectrometry now facilitates the generation of larger sets of metabolite concentration data. An important step towards the understanding of metabolite dynamics is the recognition of stable states where metabolite concentrations exhibit a simple behaviour. Such states can be characterized through the identification of significant thresholds in the concentrations. But general techniques for finding discretization thresholds in continuous data prove to be practically insufficient for detecting states due to the weak conditional dependences in concentration data. Results: We introduce a method of recognizing states in the framework of decision tree induction. It is based upon a global analysis of decision forests where stability and quality are evaluated. It leads to the detection of thresholds that are both comprehensible and robust. Applied to metabolite concentration data, this method has led to the discovery of hidden states in the corresponding variables. Some of these reflect known properties of the biological experiments, and others point to putative new states},
  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{KonczakLinkeSchaub2003,
  author    = {Konczak, Kathrin and Linke, Thomas and Schaub, Torsten H.},
  title     = {Graphs and colorings for answer set programming : abridged report},
  issn      = {1613-0073},
  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{BesnardMercerSchaub2003,
  author    = {Besnard, Philippe and Mercer, Robert E. and Schaub, Torsten H.},
  title     = {Optimality theory throught default logic},
  isbn      = {3-540-20059-2},
  year      = {2003},
  language  = {en}
}
@article{KonczakSchaubLinke2003,
  author    = {Konczak, Kathrin and Schaub, Torsten H. and Linke, Thomas},
  title     = {Graphs and colorings for answer set programming with prefernces : preliminary report},
  issn      = {1613-0073},
  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{SchaubWang2003,
  author    = {Schaub, Torsten H. and Wang, Kewen},
  title     = {A semantic framework for prefernce handling in answer set programming},
  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{Schaub2003,
  author    = {Schaub, Torsten H.},
  title     = {Antwortmengenprogrammierung},
  year      = {2003},
  language  = {de}
}
@article{KonczakSchaubLinke2003,
  author    = {Konczak, Kathrin and Schaub, Torsten H. and Linke, Thomas},
  title     = {Graphs and colorings for answer set programming with preferences},
  issn      = {0169-2968},
  year      = {2003},
  abstract  = {The integration of preferences into answer set programming constitutes an important practical device for distinguishing certain preferred answer sets from non-preferred ones. To this end, we elaborate upon rule dependency graphs and their colorings for characterizing different preference handling strategies found in the literature. We start from a characterization of (three types of) preferred answer sets in terms of totally colored dependency graphs. In particular, we demonstrate that this approach allows us to capture all three approaches to preferences in a uniform setting by means of the concept of a height function. In turn, we exemplarily develop an operational characterization of preferred answer sets in terms of operators on partial colorings for one particular strategy. In analogy to the notion of a derivation in proof theory, our operational characterization is expressed as a (non-deterministically formed) sequence of colorings, gradually turning an uncolored graph into a totally colored one},
  language  = {en}
}
@article{FloeterNicolasSchaubetal.2003,
  author    = {Fl{\"o}ter, Andr{\´e} and Nicolas, Jacques and Schaub, Torsten H. and Selbig, Joachim},
  title     = {Threshold extraction in metabolite concentration data},
  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{BesnardMercerSchaub2002,
  author    = {Besnard, Philippe and Mercer, Robert E. and Schaub, Torsten H.},
  title     = {Optimality Theory via Default Logic},
  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}
}
@article{DelgrandeHunterSchaub2002,
  author    = {Delgrande, James Patrick and Hunter, Anthony and Schaub, Torsten H.},
  title     = {COBA: a consistency-based belief revision system},
  isbn      = {3-540-44190-5},
  year      = {2002},
  language  = {en}
}
@article{SchaubWang2002,
  author    = {Schaub, Torsten H. and Wang, T.},
  title     = {Preferred well-founded semantics for logic programming by alternating fixpoints : preliminary report},
  year      = {2002},
  language  = {en}
}
@article{GebserObermeierSchaubetal.2018,
  author    = {Gebser, Martin and Obermeier, Philipp and Schaub, Torsten H. and Ratsch-Heitmann, Michel and Runge, Mario},
  title     = {Routing driverless transport vehicles in car assembly with answer set programming},
  series = {Theory and practice of logic programming},
  volume    = {18},
  journal   = {Theory and practice of logic programming},
  number    = {3-4},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {1471-0684},
  doi       = {10.1017/S1471068418000182},
  pages     = {520 -- 534},
  year      = {2018},
  abstract  = {Automated storage and retrieval systems are principal components of modern production and warehouse facilities. In particular, automated guided vehicles nowadays substitute human-operated pallet trucks in transporting production materials between storage locations and assembly stations. While low-level control systems take care of navigating such driverless vehicles along programmed routes and avoid collisions even under unforeseen circumstances, in the common case of multiple vehicles sharing the same operation area, the problem remains how to set up routes such that a collection of transport tasks is accomplished most effectively. We address this prevalent problem in the context of car assembly at Mercedes-Benz Ludwigsfelde GmbH, a large-scale producer of commercial vehicles, where routes for automated guided vehicles used in the production process have traditionally been hand-coded by human engineers. Such adhoc methods may suffice as long as a running production process remains in place, while any change in the factory layout or production targets necessitates tedious manual reconfiguration, not to mention the missing portability between different production plants. Unlike this, we propose a declarative approach based on Answer Set Programming to optimize the routes taken by automated guided vehicles for accomplishing transport tasks. The advantages include a transparent and executable problem formalization, provable optimality of routes relative to objective criteria, as well as elaboration tolerance towards particular factory layouts and production targets. Moreover, we demonstrate that our approach is efficient enough to deal with the transport tasks evolving in realistic production processes at the car factory of Mercedes-Benz Ludwigsfelde GmbH.},
  language  = {en}
}
@article{GebserKaminskiKaufmannetal.2018,
  author    = {Gebser, Martin and Kaminski, Roland and Kaufmann, Benjamin and L{\"u}hne, Patrick and Obermeier, Philipp and Ostrowski, Max and Romero Davila, Javier and Schaub, Torsten H. and Schellhorn, Sebastian and Wanko, Philipp},
  title     = {The Potsdam Answer Set Solving Collection 5.0},
  series = {K{\"u}nstliche Intelligenz},
  volume    = {32},
  journal   = {K{\"u}nstliche Intelligenz},
  number    = {2-3},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0933-1875},
  doi       = {10.1007/s13218-018-0528-x},
  pages     = {181 -- 182},
  year      = {2018},
  abstract  = {The Potsdam answer set solving collection, or Potassco for short, bundles various tools implementing and/or applying answer set programming. The article at hand succeeds an earlier description of the Potassco project published in Gebser et al. (AI Commun 24(2):107-124, 2011). Hence, we concentrate in what follows on the major features of the most recent, fifth generation of the ASP system clingo and highlight some recent resulting application systems.},
  language  = {en}
}
@article{HaubeltNeubauerSchaubetal.2018,
  author    = {Haubelt, Christian and Neubauer, Kai and Schaub, Torsten H. and Wanko, Philipp},
  title     = {Design space exploration with answer set programming},
  series = {K{\"u}nstliche Intelligenz},
  volume    = {32},
  journal   = {K{\"u}nstliche Intelligenz},
  number    = {2-3},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0933-1875},
  doi       = {10.1007/s13218-018-0530-3},
  pages     = {205 -- 206},
  year      = {2018},
  abstract  = {The aim of our project design space exploration with answer set programming is to develop a general framework based on Answer Set Programming (ASP) that finds valid solutions to the system design problem and simultaneously performs Design Space Exploration (DSE) to find the most favorable alternatives. We leverage recent developments in ASP solving that allow for tight integration of background theories to create a holistic framework for effective DSE.},
  language  = {en}
}
@misc{LifschitzSchaubWoltran2018,
  author    = {Lifschitz, Vladimir and Schaub, Torsten H. and Woltran, Stefan},
  title     = {Interview with Vladimir Lifschitz},
  series = {K{\"u}nstliche Intelligenz},
  volume    = {32},
  journal   = {K{\"u}nstliche Intelligenz},
  number    = {2-3},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0933-1875},
  doi       = {10.1007/s13218-018-0552-x},
  pages     = {213 -- 218},
  year      = {2018},
  abstract  = {This interview with Vladimir Lifschitz was conducted by Torsten Schaub at the University of Texas at Austin in August 2017. The question set was compiled by Torsten Schaub and Stefan Woltran.},
  language  = {en}
}
@misc{BrewkaSchaubWoltran2018,
  author    = {Brewka, Gerhard and Schaub, Torsten H. and Woltran, Stefan},
  title     = {Interview with Gerhard Brewka},
  series = {K{\"u}nstliche Intelligenz},
  volume    = {32},
  journal   = {K{\"u}nstliche Intelligenz},
  number    = {2-3},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {0933-1875},
  doi       = {10.1007/s13218-018-0549-5},
  pages     = {219 -- 221},
  year      = {2018},
  abstract  = {This interview with Gerhard Brewka was conducted by correspondance in May 2018. The question set was compiled by Torsten Schaub and Stefan Woltran.},
  language  = {en}
}
@article{DimopoulosGebserLuehneetal.2019,
  author    = {Dimopoulos, Yannis and Gebser, Martin and L{\"u}hne, Patrick and Romero Davila, Javier and Schaub, Torsten H.},
  title     = {plasp 3},
  series = {Theory and practice of logic programming},
  volume    = {19},
  journal   = {Theory and practice of logic programming},
  number    = {3},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {1471-0684},
  doi       = {10.1017/S1471068418000583},
  pages     = {477 -- 504},
  year      = {2019},
  abstract  = {We describe the new version of the Planning Domain Definition Language (PDDL)-to-Answer Set Programming (ASP) translator plasp. First, it widens the range of accepted PDDL features. Second, it contains novel planning encodings, some inspired by Satisfiability Testing (SAT) planning and others exploiting ASP features such as well-foundedness. All of them are designed for handling multivalued fluents in order to capture both PDDL as well as SAS planning formats. Third, enabled by multishot ASP solving, it offers advanced planning algorithms also borrowed from SAT planning. As a result, plasp provides us with an ASP-based framework for studying a variety of planning techniques in a uniform setting. Finally, we demonstrate in an empirical analysis that these techniques have a significant impact on the performance of ASP planning.},
  language  = {en}
}
@misc{NeubauerHaubeltWankoetal.2018,
  author    = {Neubauer, Kai and Haubelt, Christian and Wanko, Philipp and Schaub, Torsten H.},
  title     = {Utilizing quad-trees for efficient design space exploration with partial assignment evaluation},
  series = {2018 23rd Asia and South Pacific Design Automation Conference (ASP-DAC)},
  journal   = {2018 23rd Asia and South Pacific Design Automation Conference (ASP-DAC)},
  publisher = {IEEE},
  address   = {New York},
  isbn      = {978-1-5090-0602-1},
  issn      = {2153-6961},
  doi       = {10.1109/ASPDAC.2018.8297362},
  pages     = {434 -- 439},
  year      = {2018},
  abstract  = {Recently, it has been shown that constraint-based symbolic solving techniques offer an efficient way for deciding binding and routing options in order to obtain a feasible system level implementation. In combination with various background theories, a feasibility analysis of the resulting system may already be performed on partial solutions. That is, infeasible subsets of mapping and routing options can be pruned early in the decision process, which fastens the solving accordingly. However, allowing a proper design space exploration including multi-objective optimization also requires an efficient structure for storing and managing non-dominated solutions. In this work, we propose and study the usage of the Quad-Tree data structure in the context of partial assignment evaluation during system synthesis. Out experiments show that unnecessary dominance checks can be avoided, which indicates a preference of Quad-Trees over a commonly used list-based implementation for large combinatorial optimization problems.},
  language  = {en}
}
@misc{BosserCabalarDieguezetal.2018,
  author    = {Bosser, Anne-Gwenn and Cabalar, Pedro and Dieguez, Martin and Schaub, Torsten H.},
  title     = {Introducing temporal stable models for linear dynamic logic},
  series = {16th International Conference on Principles of Knowledge Representation and Reasoning},
  journal   = {16th International Conference on Principles of Knowledge Representation and Reasoning},
  publisher = {ASSOC Association for the Advancement of Artificial Intelligence},
  address   = {Palo Alto},
  pages     = {12 -- 21},
  year      = {2018},
  abstract  = {We propose a new temporal extension of the logic of Here-and-There (HT) and its equilibria obtained by combining it with dynamic logic over (linear) traces. Unlike previous temporal extensions of HT based on linear temporal logic, the dynamic logic features allow us to reason about the composition of actions. For instance, this can be used to exercise fine grained control when planning in robotics, as exemplified by GOLOG. In this paper, we lay the foundations of our approach, and refer to it as Linear Dynamic Equilibrium Logic, or simply DEL. We start by developing the formal framework of DEL and provide relevant characteristic results. Among them, we elaborate upon the relationships to traditional linear dynamic logic and previous temporal extensions of HT.},
  language  = {en}
}
@misc{CabalarFandinnoSchaubetal.2019,
  author    = {Cabalar, Pedro and Fandinno, Jorge and Schaub, Torsten H. and Schellhorn, Sebastian},
  title     = {Lower Bound Founded Logic of Here-and-There},
  series = {Logics in Artificial Intelligence},
  volume    = {11468},
  journal   = {Logics in Artificial Intelligence},
  publisher = {Springer},
  address   = {Cham},
  isbn      = {978-3-030-19570-0},
  issn      = {0302-9743},
  doi       = {10.1007/978-3-030-19570-0_34},
  pages     = {509 -- 525},
  year      = {2019},
  abstract  = {A distinguishing feature of Answer Set Programming is that all atoms belonging to a stable model must be founded. That is, an atom must not only be true but provably true. This can be made precise by means of the constructive logic of Here-and-There, whose equilibrium models correspond to stable models. One way of looking at foundedness is to regard Boolean truth values as ordered by letting true be greater than false. Then, each Boolean variable takes the smallest truth value that can be proven for it. This idea was generalized by Aziz to ordered domains and applied to constraint satisfaction problems. As before, the idea is that a, say integer, variable gets only assigned to the smallest integer that can be justified. In this paper, we present a logical reconstruction of Aziz' idea in the setting of the logic of Here-and-There. More precisely, we start by defining the logic of Here-and-There with lower bound founded variables along with its equilibrium models and elaborate upon its formal properties. Finally, we compare our approach with related ones and sketch future work.},
  language  = {en}
}
@article{FriouxSchaubSchellhornetal.2019,
  author    = {Frioux, Cl{\´e}mence and Schaub, Torsten H. and Schellhorn, Sebastian and Siegel, Anne and Wanko, Philipp},
  title     = {Hybrid metabolic network completion},
  series = {Theory and practice of logic programming},
  volume    = {19},
  journal   = {Theory and practice of logic programming},
  number    = {1},
  publisher = {Cambridge University Press},
  address   = {New York},
  issn      = {1471-0684},
  doi       = {10.1017/S1471068418000455},
  pages     = {83 -- 108},
  year      = {2019},
  abstract  = {Metabolic networks play a crucial role in biology since they capture all chemical reactions in an organism. While there are networks of high quality for many model organisms, networks for less studied organisms are often of poor quality and suffer from incompleteness. To this end, we introduced in previous work an answer set programming (ASP)-based approach to metabolic network completion. Although this qualitative approach allows for restoring moderately degraded networks, it fails to restore highly degraded ones. This is because it ignores quantitative constraints capturing reaction rates. To address this problem, we propose a hybrid approach to metabolic network completion that integrates our qualitative ASP approach with quantitative means for capturing reaction rates. We begin by formally reconciling existing stoichiometric and topological approaches to network completion in a unified formalism. With it, we develop a hybrid ASP encoding and rely upon the theory reasoning capacities of the ASP system dingo for solving the resulting logic program with linear constraints over reals. We empirically evaluate our approach by means of the metabolic network of Escherichia coli. Our analysis shows that our novel approach yields greatly superior results than obtainable from purely qualitative or quantitative approaches.},
  language  = {en}
}
@article{BanbaraInoueKaufmannetal.2018,
  author    = {Banbara, Mutsunori and Inoue, Katsumi and Kaufmann, Benjamin and Okimoto, Tenda and Schaub, Torsten H. and Soh, Takehide and Tamura, Naoyuki and Wanko, Philipp},
  title     = {teaspoon},
  series = {Annals of operation research},
  volume    = {275},
  journal   = {Annals of operation research},
  number    = {1},
  publisher = {Springer},
  address   = {Dordrecht},
  issn      = {0254-5330},
  doi       = {10.1007/s10479-018-2757-7},
  pages     = {3 -- 37},
  year      = {2018},
  abstract  = {Answer Set Programming (ASP) is an approach to declarative problem solving, combining a rich yet simple modeling language with high performance solving capacities. We here develop an ASP-based approach to curriculum-based course timetabling (CB-CTT), one of the most widely studied course timetabling problems. The resulting teaspoon system reads a CB-CTT instance of a standard input format and converts it into a set of ASP facts. In turn, these facts are combined with a first-order encoding for CB-CTT solving, which can subsequently be solved by any off-the-shelf ASP systems. We establish the competitiveness of our approach by empirically contrasting it to the best known bounds obtained so far via dedicated implementations. Furthermore, we extend the teaspoon system to multi-objective course timetabling and consider minimal perturbation problems.},
  language  = {en}
}
@article{BibelBrueningOttenetal.1998,
  author    = {Bibel, Wolfgang and Br{\"u}ning, Stefan and Otten, Jens and Rath, Thomas and Schaub, Torsten H.},
  title     = {Compressions and extensions},
  year      = {1998},
  language  = {en}
}
@article{DelgrandeSchaub1997,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {Compiling specificity into approaches to nonmonotonic reasoning},
  issn      = {0004-3702},
  year      = {1997},
  language  = {en}
}
@article{LinkeSchaub1997,
  author    = {Linke, Thomas and Schaub, Torsten H.},
  title     = {Towards a classification of default logic},
  year      = {1997},
  language  = {en}
}
@article{SchaubBruening1996,
  author    = {Schaub, Torsten H. and Br{\"u}ning, Stefan},
  title     = {Prolog technology for default reasoning},
  isbn      = {0-471-96809-9},
  year      = {1996},
  language  = {en}
}
@article{BesnardSchaub1996,
  author    = {Besnard, Philippe and Schaub, Torsten H.},
  title     = {A simple signed system for paraconsistent reasoning},
  isbn      = {3-540-61630-6},
  year      = {1996},
  language  = {en}
}
@article{SchaubThielscher1996,
  author    = {Schaub, Torsten H. and Thielscher, Michael},
  title     = {Skeptical query-answering in constrained default logic},
  isbn      = {3-540-61313-7},
  year      = {1996},
  language  = {en}
}
@article{SchaubBrueningNicolas1996,
  author    = {Schaub, Torsten H. and Br{\"u}ning, Stefan and Nicolas, Pascal},
  title     = {XRay : a prolog technology theorem prover for default reasoning: a system description},
  isbn      = {3-540-61511-3},
  year      = {1996},
  language  = {en}
}
@article{LinkeSchaub1996,
  author    = {Linke, Thomas and Schaub, Torsten H.},
  title     = {Putting default logics in perspective},
  isbn      = {3-540-61708-6},
  year      = {1996},
  language  = {en}
}
@article{BrueningSchaub1996,
  author    = {Br{\"u}ning, Stefan and Schaub, Torsten H.},
  title     = {A model-based approach to consistency-checking},
  isbn      = {3-540-61286-6},
  year      = {1996},
  language  = {en}
}
@article{GebserKaufmannNeumannetal.2007,
  author    = {Gebser, Martin and Kaufmann, Benjamin and Neumann, Andr{\´e} and Schaub, Torsten H.},
  title     = {Conflict-driven answer set enumeration},
  isbn      = {978-3-540- 72199-4},
  year      = {2007},
  language  = {en}
}
@article{GebserKaufmannNeumannetal.2007,
  author    = {Gebser, Martin and Kaufmann, Benjamin and Neumann, Andr{\´e} and Schaub, Torsten H.},
  title     = {Conflict-driven answer set solving},
  isbn      = {978-1-57735-323-2},
  year      = {2007},
  language  = {en}
}
@article{DelgrandeLiuSchaubetal.2007,
  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      = {2007},
  language  = {en}
}
@article{DelgrandeSchaub2007,
  author    = {Delgrande, James Patrick and Schaub, Torsten H.},
  title     = {A consistency-based framework for merging knowledge bases},
  issn      = {1570-8683},
  year      = {2007},
  language  = {en}
}
@article{GebserGharibSchaub2007,
  author    = {Gebser, Martin and Gharib, Mona and Schaub, Torsten H.},
  title     = {Incremental answer sets and their computation},
  year      = {2007},
  language  = {en}
}
@article{GebserSchaub2007,
  author    = {Gebser, Martin and Schaub, Torsten H.},
  title     = {Generic tableaux for answer set programming},
  year      = {2007},
  language  = {en}
}
@article{GebserKaufmannNeumannetal.2007,
  author    = {Gebser, Martin and Kaufmann, Benjamin and Neumann, Andr{\´e} and Schaub, Torsten H.},
  title     = {Clasp : a conflict-driven answer set solver},
  isbn      = {978-3-540- 72199-4},
  year      = {2007},
  language  = {en}
}
@article{BenhammadiNicolasSchaub1998,
  author    = {Benhammadi, Farid and Nicolas, Pascal and Schaub, Torsten H.},
  title     = {Extension calculus and query answering in prioritized default logic},
  isbn      = {3-540-64993-X},
  year      = {1998},
  language  = {en}
}
@article{BesnardSchaub1993,
  author    = {Besnard, Philippe and Schaub, Torsten H.},
  title     = {A context-based framework for default logics},
  isbn      = {0-262-51071-5},
  year      = {1993},
  language  = {en}
}
@article{DelgrandeSchaubTompits2007,
  author    = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans},
  title     = {A general framework for expressing preferences in causal reasoning and planning},
  issn      = {0955-792X},
  doi       = {10.1093/logcom/exm046},
  year      = {2007},
  abstract  = {We consider the problem of representing arbitrary preferences in causal reasoning and planning systems. In planning, a preference may be seen as a goal or constraint that is desirable, but not necessary, to satisfy. To begin, we define a very general query language for histories, or interleaved sequences of world states and actions. Based on this, we specify a second language in which preferences are defined. A single preference defines a binary relation on histories, indicating that one history is preferred to the other. From this, one can define global preference orderings on the set of histories, the maximal elements of which are the preferred histories. The approach is very general and flexible; thus it constitutes a base language in terms of which higher-level preferences may be defined. To this end, we investigate two fundamental types of preferences that we call choice and temporal preferences. We consider concrete strategies for these types of preferences and encode them in terms of our framework. We suggest how to express aggregates in the approach, allowing, e.g. the expression of a preference for histories with lowest total action costs. Last, our approach can be used to express other approaches and so serves as a common framework in which such approaches can be expressed and compared. We illustrate this by indicating how an approach due to Son and Pontelli can be encoded in our approach, as well as the language PDDL3.},
  language  = {en}
}
@article{GebserSchaub2013,
  author    = {Gebser, Martin and Schaub, Torsten H.},
  title     = {Tableau calculi for logic programs under answer set semantics},
  series = {ACM transactions on computational logic},
  volume    = {14},
  journal   = {ACM transactions on computational logic},
  number    = {2},
  publisher = {Association for Computing Machinery},
  address   = {New York},
  issn      = {1529-3785},
  doi       = {10.1145/2480759.2480767},
  pages     = {40},
  year      = {2013},
  abstract  = {We introduce formal proof systems based on tableau methods for analyzing computations in Answer Set Programming (ASP). Our approach furnishes fine-grained instruments for characterizing operations as well as strategies of ASP solvers. The granularity is detailed enough to capture a variety of propagation and choice methods of algorithms used for ASP solving, also incorporating SAT-based and conflict-driven learning approaches to some extent. This provides us with a uniform setting for identifying and comparing fundamental properties of ASP solving approaches. In particular, we investigate their proof complexities and show that the run-times of best-case computations can vary exponentially between different existing ASP solvers. Apart from providing a framework for comparing ASP solving approaches, our characterizations also contribute to their understanding by pinning down the constitutive atomic operations. Furthermore, our framework is flexible enough to integrate new inference patterns, and so to study their relation to existing ones. To this end, we generalize our approach and provide an extensible basis aiming at a modular incorporation of additional language constructs. This is exemplified by augmenting our basic tableau methods with cardinality constraints and disjunctions.},
  language  = {en}
}
@article{LinkeSchaub1998,
  author    = {Linke, Thomas and Schaub, Torsten H.},
  title     = {An approach to query-answering in Reiter's default logic and the underlying existence of extensions problem.},
  isbn      = {3-540-65141-1},
  year      = {1998},
  language  = {en}
}
@article{VolkmannLinkeWaschulziketal.1998,
  author    = {Volkmann, Gerald and Linke, Thomas and Waschulzik, Thomas and Ohmes, Rick and Schaub, Torsten H. and Wischnewsky, M.},
  title     = {HExProSA - ein hybrides Expertensystem zur Prozeßkontrolle und St{\"o}rfallanalyse von Abwasserbehandlungsanlagen : Erfahrungen bei der Evaluierung eines Prototypen},
  year      = {1998},
  language  = {de}
}
@article{BenhammadiNicolasSchaub1998,
  author    = {Benhammadi, Farid and Nicolas, Pascal and Schaub, Torsten H.},
  title     = {Extension calculus and query answering in prioritized default logic},
  isbn      = {3-540- 64993-X},
  year      = {1998},
  language  = {en}
}
@article{BesnardSchaub1998,
  author    = {Besnard, Philippe and Schaub, Torsten H.},
  title     = {Signed systems for paraconsistent reasoning},
  year      = {1998},
  language  = {en}
}