To resolve conflicts amongst norms, various non-monotonic formalisms can be used to perform prioritized normative reasoning. Meanwhile, formal argumentation provides a way to represent non-monotonic logics. The University of Luxembourg, together with Zhejiang University and CNRS Sophia Antipolis is conducting research on prioritized norms in formal argumentation.

Since the work of Alchourrón and Makinson on hierarchies of regulations and their logic, in which a partial ordering on a code of laws or regulations is used to overcome logical imperfections
in the code itself, reasoning with prioritized norms has been a central challenge in deontic logic.

On the other hand, in the last decades computational argumentation has emerged as a powerful approach to the study of reasoning in the presence of incomplete and conflicting information with a wide range of applications in Artificial Intelligence. In this context several formalisms at various levels of abstraction have been developed, in order to support the investigation of general and reusable properties, valid for all the instances of a given abstract model.

Current research carried out at the University of Luxembourg addresses the open issue of reasoning with priorities over norms through the lens of argumentation theory.

Main contributor(s): Beishui Liao, Leon van der Torre