Search Results for author: Markus Hecher

Found 15 papers, 3 papers with code

Utilizing Treewidth for Quantitative Reasoning on Epistemic Logic Programs

1 code implementation6 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.

The Model Counting Competition 2020

no code implementations2 Dec 2020 Johannes K. Fichte, Markus Hecher, Florim Hamiti

We hope that the results can be a good indicator of the current feasibility of model counting and spark many new applications.

Solving the Steiner Tree Problem with few Terminals

no code implementations9 Nov 2020 Johannes K. Fichte, Markus Hecher, Andre Schidler

We show that admissibility is indeed weaker than consistency and establish correctness of the DS* algorithm when using an admissible heuristic function.

A Time Leap Challenge for SAT Solving

no code implementations5 Aug 2020 Johannes K. Fichte, Markus Hecher, Stefan Szeider

We compare the impact of hardware advancement and algorithm advancement for SAT solving over the last two decades.

Treewidth-Aware Complexity in ASP: Not all Positive Cycles are Equally Hard

no code implementations9 Jul 2020 Markus Hecher, Jorge Fandinno

The exponential time hypothesis (ETH) implies that this result is tight for SAT, that is, SAT cannot be solved in subexponential time.

Structural Decompositions of Epistemic Logic Programs

no code implementations13 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.

Lower Bounds for QBFs of Bounded Treewidth

no code implementations2 Oct 2019 Johannes Klaus Fichte, Markus Hecher, Andreas Pfandler

More formally, we establish lower bounds for QSAT and treewidth, namely, that under ETH there cannot be an algorithm that solves QSAT of quantifier depth i in runtime significantly better than i-fold exponential in the treewidth and polynomial in the input size.

Inconsistency Proofs for ASP: The ASP-DRUPE Format

no code implementations24 Jul 2019 Mario Alviano, Carmine Dodaro, Johannes K. Fichte, Markus Hecher, Tobias Philipp, Jakob Rath

Verifying whether a claimed answer set is formally a correct answer set of the program can be decided in polynomial time for (normal) programs.

Counting Complexity for Reasoning in Abstract Argumentation

no code implementations28 Nov 2018 Johannes K. Fichte, Markus Hecher, Arne Meier

In this paper, we consider counting and projected model counting of extensions in abstract argumentation for various semantics.

Abstract Argumentation

Exploiting Treewidth for Projected Model Counting and its Limits

no code implementations14 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.

Default Logic and Bounded Treewidth

no code implementations28 Jun 2017 Johannes K. Fichte, Markus Hecher, Irina Schindler

In this paper, we study Reiter's propositional default logic when the treewidth of a certain graph representation (semi-primal graph) of the input theory is bounded.

DynASP2.5: Dynamic Programming on Tree Decompositions in Action

1 code implementation28 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.

Answer Set Solving with Bounded Treewidth Revisited

1 code implementation9 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.

Counting Answer Sets via Dynamic Programming

no code implementations22 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).

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