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Markus Hecher

24 accepted papers

2026

Structure-Aware Encodings of Argumentation Properties for Clique-width

AAAI 2026technical

Structural measures of graphs, such as treewidth, are central tools in computational complexity resulting in efficient algorithms when exploiting the parameter. It is even known that modern SAT solvers work efficiently on instances of small treewidth. Since these solvers are widely applied, research

Cited by 0SourcePDFScholar
2025

Counting and Reasoning with Plans

AAAI 2025technical

Classical planning asks for a sequence of operators reaching a given goal. While the most common case is to compute a plan, many scenarios require more than that. However, quantitative reasoning on the plan space remains mostly unexplored. A fundamental problem is to count plans, which relates to th…

Cited by 0SourcePDFScholar
2025

Dung’s Argumentation Framework: Unveiling the Expressive Power with Inconsistent Databases

AAAI 2025technical

The connection between inconsistent databases and Dung’s abstract argumentation framework has recently drawn growing interest. Specifically, an inconsistent database, involving certain types of integrity constraints such as functional and inclusion dependencies, can be viewed as an argumentation fra…

Cited by 0SourcePDFScholar
2025

Facets in Argumentation: A Formal Approach to Argument Significance

IJCAI 2025

Argumentation is a central subarea of Artificial Intelligence (AI) for modeling and reasoning about arguments. The semantics of abstract argumentation frameworks (AFs) is given by sets of arguments (extensions) and conditions on the relationship between arguments, such as stable or admissible. Today

Cited by 0SourcePDFScholar
2024

Bypassing the ASP Bottleneck: Hybrid Grounding by Splitting and Rewriting

IJCAI 2024poster

Answer Set Programming (ASP) is a key paradigm for problems in artificial intelligence and industrial contexts. In ASP, problems are modeled via a set of rules. Over the time this paradigm grew into a rich language, enabling complex rule types like aggregate expressions. Most practical ASP systems f…

Cited by 1SourcePDFScholar
2024

Epistemic Logic Programs: Non-Ground and Counting Complexity

IJCAI 2024poster

Answer Set Programming (ASP) is a prominent problem-modeling and solving framework, whose solutions are called answer sets. Epistemic logic programs (ELP) extend ASP to reason about all or some answer sets. Solutions to an ELP can be seen as consequences over multiple collections of answer sets, kno…

Cited by 3SourcePDFScholar
2024

Finite Groundings for ASP with Functions: A Journey through Consistency

IJCAI 2024poster

Answer set programming (ASP) is a logic programming formalism used in various areas of artificial intelligence like combinatorial problem solving and knowledge representation and reasoning. It is known that enhancing ASP with function symbols makes basic reasoning problems highly undecidable. Howeve…

Cited by 0SourcePDFScholar
2024

On the Structural Hardness of Answer Set Programming: Can Structure Efficiently Confine the Power of Disjunctions?

AAAI 2024technical

Answer Set Programming (ASP) is a generic problem modeling and solving framework with a strong focus on knowledge representation and a rapid growth of industrial applications. So far, the study of complexity resulted in characterizing hardness and determining their sources, fine-grained insights in…

Cited by 0SourcePDFScholar
2024

Parallel Empirical Evaluations: Resilience despite Concurrency

AAAI 2024technical

Computational evaluations are crucial in modern problem-solving when we surpass theoretical algorithms or bounds. These experiments frequently take much work, and the sheer amount of needed resources makes it impossible to execute them on a single personal computer or laptop. Cluster schedulers allo…

2024

Quantitative Claim-Centric Reasoning in Logic-Based Argumentation

IJCAI 2024poster

Argumentation is a well-established formalism for nonmonotonic reasoning, with popular frameworks being Dung’s abstract argumentation (AFs) or logic-based argumentation (Besnard-Hunter’s framework). Structurally, a set of formulas forms support for a claim if it is consistent, subset-minimal, and im…

Cited by 2SourcePDFScholar
2023

Characterizing Structural Hardness of Logic Programs: What Makes Cycles and Reachability Hard for Treewidth?

AAAI 2023technical

Answer Set Programming (ASP) is a problem modeling and solving framework for several problems in KR with growing industrial applications. Also for studies of computational complexity and deeper insights into the hardness and its sources, ASP has been attracting researchers for many years. These stud…

Cited by 2SourcePDFScholar
2023

Inconsistent Cores for ASP: The Perks and Perils of Non-monotonicity

AAAI 2023technical

Answer Set Programming (ASP) is a prominent modeling and solving framework. An inconsistent core (IC) of an ASP program is an inconsistent subset of rules. In the case of inconsistent programs, a smallest or subset-minimal IC contains crucial rules for the inconsistency. In this work, we study fndin…

2023

Quantitative Reasoning and Structural Complexity for Claim-Centric Argumentation

IJCAI 2023poster

Argumentation is a well-established formalism for nonmonotonic reasoning and a vibrant area of research in AI. Claim-augmented argumentation frameworks (CAFs) have been introduced to deploy a conclusion-oriented perspective. CAFs expand argumentation frameworks by an additional step which involves r…

Cited by 5SourcePDFScholar
2022

ApproxASP – a Scalable Approximate Answer Set Counter

AAAI 2022technical

Answer Set Programming (ASP) is a framework in artificial intelligence and knowledge representation for declarative modeling and problem solving. Modern ASP solvers focus on the computation or enumeration of answer sets. However, a variety of probabilistic applications in reasoning or logic programm…

Cited by 20SourcePDFScholar
2022

Body-Decoupled Grounding via Solving: A Novel Approach on the ASP Bottleneck

IJCAI 2022poster

Answer-Set Programming (ASP) has seen tremendous progress over the last two decades and is nowadays successfully applied in many real-world domains. However, for certain types of problems, the well-known ASP grounding bottleneck still causes severe problems. This becomes virulent when grounding of r…

2022

Plausibility Reasoning via Projected Answer Set Counting - A Hybrid Approach

IJCAI 2022poster

Answer set programming is a form of declarative programming widely used to solve difficult search problems. Probabilistic applications however require to go beyond simple search for one solution and need counting. One such application is plausibility reasoning, which provides more fine-grained reaso…

2022

Tractable Abstract Argumentation via Backdoor-Treewidth

AAAI 2022technical

Argumentation frameworks (AFs) are a core formalism in the field of formal argumentation. As most standard computational tasks regarding AFs are hard for the first or second level of the Polynomial Hierarchy, a variety of algorithmic approaches to achieve manageable runtimes have been considered in…

2022

Utilizing Treewidth for Quantitative Reasoning on Epistemic Logic Programs (Extended Abstract)

IJCAI 2022poster

Extending the popular Answer Set Programming (ASP) paradigm by introspective reasoning capacities has received increasing interest within the last years. Particular attention is given to the formalism of epistemic logic programs (ELPs) where standard rules are equipped with modal operators which all…

2021

Decomposition-Guided Reductions for Argumentation and Treewidth

IJCAI 2021poster

Argumentation is a widely applied framework for modeling and evaluating arguments and its reasoning with various applications. Popular frameworks are abstract argumentation (Dung’s framework) or logic-based argumentation (Besnard-Hunter’s framework). Their computational complexity has been studied q…

Cited by 16SourcePDFScholar