no code implementations • 15 Jan 2014 • Tomi Janhunen, Emilia Oikarinen, Hans Tompits, Stefan Woltran
Practically all programming languages allow the programmer to split a program into several modules which brings along several advantages in software development.
no code implementations • 16 Jan 2014 • Wolfgang Dvorak, Stefan Woltran
Translations between different nonmonotonic formalisms always have been an important topic in the field, in particular to understand the knowledge-representation capabilities those formalisms offer.
no code implementations • 25 Apr 2014 • Nadia Creignou, Odile Papini, Stefan Rümmele, Stefan Woltran
This paper presents a general approach to define new merging operators derived from existing ones such that the result of merging remains in the fragment under consideration.
no code implementations • 30 Apr 2014 • Ringo Baumann, Wolfgang Dvorák, Thomas Linsbichler, Hannes Strass, Stefan Woltran
(3) Finally, we show that compact AFs are indeed a non-trivial subclass, since the verification problem remains coNP-hard for certain semantics.
no code implementations • 20 Jul 2015 • Johannes K. Fichte, Miroslaw Truszczynski, Stefan Woltran
Identifying classes of programs for which the consistency problem is in NP is of interest from the theoretical standpoint and can potentially lead to improvements in the design of answer set programming solvers.
no code implementations • 23 Jul 2015 • Sarah A. Gaggl, Norbert Manthey, Alessandro Ronca, Johannes P. Wallner, Stefan Woltran
The design of efficient solutions for abstract argumentation problems is a crucial step towards advanced argumentation systems.
no code implementations • 31 Mar 2016 • Adrian Haret, Jean-Guy Mailly, Stefan Woltran
In other words, we are interested in seeing if $K$ can be distributed into knowledge bases of simpler structure, such that the task of merging allows for a reconstruction of the original knowledge.
no code implementations • 31 Mar 2016 • Ringo Baumann, Thomas Linsbichler, Stefan Woltran
Dung's abstract argumentation theory is a widely used formalism to model conflicting information and to draw conclusions in such situations.
no code implementations • 30 Jun 2016 • Bernhard Bliem, Sebastian Ordyniak, Stefan Woltran
We then consider the graph parameter of signed clique-width and present a novel dynamic programming algorithm that is FPT w. r. t.
no code implementations • 5 Aug 2016 • Manuel Bichler, Michael Morak, Stefan Woltran
In its traditional application, a fixed ASP program for a given problem is designed and the actual instance of the problem is fed into the program as a set of facts.
no code implementations • 19 Aug 2016 • Manuel Bichler, Michael Morak, Stefan Woltran
State-of-the-art answer set programming (ASP) solvers rely on a program called a grounder to convert non-ground programs containing variables into variable-free, propositional programs.
no code implementations • 22 Dec 2016 • Johannes Fichte, Markus Hecher, Michael Morak, Stefan Woltran
While the solution counting problem for propositional satisfiability (#SAT) has received renewed attention in recent years, this research trend has not affected other AI solving paradigms like answer set programming (ASP).
1 code implementation • 9 Feb 2017 • Johannes Fichte, Markus Hecher, Michael Morak, Stefan Woltran
Parameterized algorithms are a way to solve hard problems more efficiently, given that a specific parameter of the input is small.
1 code implementation • 28 Jun 2017 • Johannes K. Fichte, Markus Hecher, Michael Morak, Stefan Woltran
In this paper, we describe underlying concepts of our new implementation (DynASP2. 5) that shows competitive behavior to state-of-the-art ASP solvers even for finding just one solution when solving problems as the Steiner tree problem that have been modeled in ASP on graphs with low treewidth.
no code implementations • 17 Jul 2017 • Ricardo Gonçalves, Matthias Knorr, João Leite, Stefan Woltran
However, it is an open question what to do when we have to forget a set of atoms, but cannot without violating this property.
no code implementations • 14 May 2018 • Johannes K. Fichte, Michael Morak, Markus Hecher, Stefan Woltran
It runs in time $O({2^{2^{k+4}} n^2})$ where k is the treewidth and n is the input size of the instance.
no code implementations • 20 Jun 2018 • Gerhard Brewka, Jörg Pührer, Hannes Strass, Johannes P. Wallner, Stefan Woltran
Abstract Dialectical Frameworks (ADFs) generalize Dung's argumentation frameworks allowing various relationships among arguments to be expressed in a systematic way.
no code implementations • 25 Jul 2019 • Wolfgang Faber, Michael Morak, Stefan Woltran
Epistemic Logic Programs (ELPs) extend Answer Set Programming (ASP) with epistemic negation and have received renewed interest in recent years.
no code implementations • 2 Sep 2019 • Sarah A. Gaggl, Thomas Linsbichler, Marco Maratea, Stefan Woltran
Argumentation is a major topic in the study of Artificial Intelligence.
no code implementations • 5 Dec 2019 • Gerhard Brewka, Martin Diller, Georg Heissenberger, Thomas Linsbichler, Stefan Woltran
Powerful formalisms for abstract argumentation have been proposed, among them abstract dialectical frameworks (ADFs) that allow for a succinct and flexible specification of the relationship between arguments, and the GRAPPA framework which allows argumentation scenarios to be represented as arbitrary edge-labelled graphs.
no code implementations • 4 Jan 2020 • Manuel Bichler, Michael Morak, Stefan Woltran
Epistemic Logic Programs (ELPs) are an extension of Answer Set Programming (ASP) with epistemic operators that allow for a form of meta-reasoning, that is, reasoning over multiple possible worlds.
no code implementations • 13 Jan 2020 • Markus Hecher, Michael Morak, Stefan Woltran
Epistemic logic programs (ELPs) are a popular generalization of standard Answer Set Programming (ASP) providing means for reasoning over answer sets within the language.
no code implementations • 13 Jan 2020 • Johannes K. Fichte, Markus Hecher, Patrick Thier, Stefan Woltran
This paper deals with counting problems for instances of small treewidth.
no code implementations • 7 Jul 2020 • Wolfgang Dvořák, Atefeh Keshavarzi Zafarghandi, Stefan Woltran
Generalizing the attack structure in argumentation frameworks (AFs) has been studied in different ways.
1 code implementation • 6 Aug 2021 • Viktor Besin, Markus Hecher, Stefan Woltran
In this paper, we take a next step and contribute to epistemic logic programming in two ways: First, we establish quantitative reasoning for ELPs, where the acceptance of a certain set of literals depends on the number (proportion) of world views that are compatible with the set.
no code implementations • 7 Sep 2021 • Wolfgang Dvořák, Matthias König, Johannes P. Wallner, Stefan Woltran
In this solver description we present ASPARTIX-V, in its 2021 edition, which participates in the International Competition on Computational Models of Argumentation (ICCMA) 2021.
no code implementations • 28 Apr 2022 • Michael Bernreiter, Wolfgang Dvorak, Anna Rapberger, Stefan Woltran
In this paper, we study the effect of preferences in abstract argumentation under a claim-centric perspective.
no code implementations • 6 May 2022 • Wolfgang Dvořák, Matthias König, Markus Ulbricht, Stefan Woltran
We extend the principle-based approach to Argumentation Frameworks with Collective Attacks (SETAFs) and provide a comprehensive overview of common principles for their semantics.
no code implementations • 30 May 2023 • Johannes K. Fichte, Markus Hecher, Michael Morak, Patrick Thier, Stefan Woltran
Inspired by the observation that the so-called "treewidth" is one of the most prominent structural parameters, our algorithm utilizes small treewidth of the primal graph of the input instance.
no code implementations • 13 Dec 2023 • Zeynep G. Saribatur, Stefan Woltran
Answer Set Programming (ASP) is a prominent rule-based language for knowledge representation and reasoning with roots in logic programming and non-monotonic reasoning.