TY - JOUR
A1 - Sarsakov, Vladimir
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - A compiler for nested logic programming
Y1 - 2004
SN - 3-540- 20721-x
ER -
TY - JOUR
A1 - Pearce, David
A1 - Sarsakov, Vladimir
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - A polynomial translation of logic programs with nested expressions into disjunctive logic programs : preliminary report
Y1 - 2002
ER -
TY - JOUR
A1 - Pearce, David
A1 - Sarsakov, Vladimir
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - A polynomial translation of logic programs with nested expressions into disjunctive logic programs
Y1 - 2002
SN - 3-540-43930-7
ER -
TY - JOUR
A1 - Linke, Thomas
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - On Acyclic and head-cycle free nested logic programs
Y1 - 2004
SN - 3-540-22671-01
ER -
TY - JOUR
A1 - Linke, Thomas
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - On acyclic and head-cycle free nested logic programs
Y1 - 2004
ER -
TY - JOUR
A1 - Gebser, Martin
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - Alternative characterizations for program equivalence under aswer-set semantics : a preliminary report
Y1 - 2007
ER -
TY - JOUR
A1 - Delgrande, James
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - A model-theoretic approach to belief change in answer set programming
JF - ACM transactions on computational logic
N2 - 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.
KW - Theory
KW - Answer set programming
KW - belief revision
KW - belief merging
KW - program encodings
KW - strong equivalence
Y1 - 2013
U6 - http://dx.doi.org/10.1145/2480759.2480766
SN - 1529-3785 (print)
VL - 14
IS - 2
PB - Association for Computing Machinery
CY - New York
ER -
TY - JOUR
A1 - Delgrande, James Patrick
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - On computing solutions to belief change scenarios
Y1 - 2001
SN - 3-540- 42464-4
ER -
TY - JOUR
A1 - Delgrande, James Patrick
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - On Computing belief change operations using quantifield boolean formulas
N2 - 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
Y1 - 2004
SN - 0955-792X
ER -
TY - JOUR
A1 - Brain, Martin
A1 - Gebser, Martin
A1 - Pührer, Jörg
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - "That is illogical, Captain!" : the debugging support tool spock for answer-set programs ; system description
Y1 - 2007
ER -
TY - JOUR
A1 - Brain, Martin
A1 - Gebser, Martin
A1 - Pührer, Jörg
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - Debugging ASP programs by means of ASP
Y1 - 2007
SN - 978-3-540- 72199-4
ER -
TY - JOUR
A1 - Besnard, Philippe
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - Paraconsistent reasoning via quantified boolean formulas : Part II: Circumscribing inconsistent theories
Y1 - 2003
SN - 3-540- 409494-5
ER -
TY - JOUR
A1 - Besnard, Philippe
A1 - Schaub, Torsten
A1 - Tompits, Hans
A1 - Woltran, Stefan
T1 - Paraconsistent reasoning via quantified boolean formulas
Y1 - 2002
SN - 3-540-44190-5
ER -