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The formalisation of defeasible reasoning in automated systems is becoming increasingly important. Description Logics (DLs) are nowadays the main logical formalism in the field of formal ontologies. Our focus in this paper is to devise a practical implementation for prior work that formalises a version of Rational Closure (an important type of defeasible reasoning) for DLs. We show that the con...

This extended research abstract describes an argumentation-based approach to modelling articulated decision making contexts. The approach encompasses a variety of argument and attack schemes aimed at representing basic knowledge and reasoning patterns for decision support.

A~STRCT. This paper argues for the re-conceptu~i~t~on of geopolitics using the concept of discourse. Geopolitics is defined as a discursive practice by which inteltectuals of statecraft ‘spatialize’ international politics and represent it as a ‘world characterized by particular types of places, peoples and dramas, Four theses explicating this re-conceptualization are outlined including the dist...

This paper describes a framework for practical reasoning in the presence of norms. We describe a formal normative model constructed using Action-based Alternating Transition Systems. This model is able to represent goals; obligations and prohibitions and their violation; and permissions, which are used to derogate the former. Inspired by Atkinson’s scheme for practical reasoning, we utilise arg...

One of the problems that must be dealt with in either a formal or implemented temporal reasoning system is the ambiguity arising from uncertain information. Lack of precise information about when events happen leads to uncertainty regarding the effects of those events. Incomplete information and nonmonotonic inference lead to situations where there is more than one set of possible inferences, e...

The preferential approach to nonmonotonic reasoning was consolidated in depth by Krause, Lehmann and Magidor (KLM) for propositional logic in the early 90’s. In recent years, there have been efforts to extend their framework to Description Logics (DLs) and a solid (though preliminary) theoretical foundation has already been established towards this aim. Despite this foundation, the generalisati...

In this paper a representative example is chosen that is meant be fairly simple for illustrating the point that in a very common kind of instance, argument and explanation are mixed in together in a text of discourse. The example is a short text found on the Internet that explains to the reader how to attach a flagpole bracket to the vinyl siding on the side of your house. The example uses prac...

In this paper we study a DL rich enough to express UML class diagrams including ISA and disjointness between classes (but not covering constraints), typing of associations, and participation and functional cardinality constraints. For such a DL, which we call DL-Lite, we propose novel reasoning techniques for a variety of tasks, notably including query containment and query answering for conjun...

In a normative environment an agent’s actions are not only directed by its goals but also by norms. Here, potential conflicts among the agent’s goals and norms makes decision-making challenging. We therefore seek to answer the following questions: (i) how should an agent act in a normative environment? and (ii) how can the agent explain why it acted in a certain way? We propose a solution in wh...