Gustav Nordh

A Trichotomy in the Complexity of Propositional Circumscription

Circumscription is one of the most important and well studied formalisms in the realm of nonmonotonic reasoning. The inference problem for propositional circumscription has been extensively studied from the viewpoint of computational complexity. We prove that there exists a trichotomy for the complexity of the inference problem in propositional variable circumscription. More specifically we prove that every restricted case of the problem is either \(\Pi_{\rm 2}^{\rm P}\)-complete, coNP-complete, or in P.

Retractions to Pseudoforests

For a fixed graph

MAX ONES Generalized to Larger Domains

H

The maximum solution problem on graphs

, let

Introduction to the Maximum Solution Problem

\textsc{Ret}(H)

An algebraic approach to the complexity of propositional circumscription

denote the problem of deciding whether a given input graph is retractable to

Generalised integer programming based on logically defined relations

H

The Complexity of Counting Solutions to Systems of Equations over Finite Semigroups

. We classify the complexity of

A note on the hardness of Skolem-type sequences

\textsc{Ret}(H)

Strong partial clones and the time complexity of SAT problems

when