http://repub.eur.nl/res/aut/3109/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/517/ 1997-01-01T00:00:00Z A theory of diagnosis and qualitative decision theory are able to formalize reasoning `with' norms. They are thus different from deontic logic, that formalizes reasoning `about' norms. In this paper, we compare two theories of diagnosis for normative systems: Ramos and Fiadeiro's theory of diagnosis developed for organizational process design and Tan and Van der Torre's theory of diagnosis extended with notions of qualitative decision theory. We observe several similarities. http://repub.eur.nl/res/pub/518/ 1997-01-01T00:00:00Z In this article we propose contextual deontic logic (CDL). Contextual obligations are written as O(Alpha|Beta\\Gamma), and are to be read as `Alpha should be the case if Beta is the case, unless Gamma is the case'. The unless clause is analogous to the justification in Reiter's default rules. We show how contextual obligations can be used to solve certain aspects of contrary-to-duty paradoxes of dyadic deontic logic. http://repub.eur.nl/res/pub/512/ 1996-01-01T00:00:00Z In this paper, we show how to extend the Petri net formalism to represent different types of behavior, in particular normative behavior. This extension is motivated by the use of Petri nets to model bureaucratic procedures, which contain normative aspects like obligations and permissions. We propose to extend Petri nets with a preference relation, a well-known mechanism from deontic logic to discriminate between ideal and varying sub-ideal states. http://repub.eur.nl/res/pub/454/ 1995-01-01T00:00:00Z In this paper we give a general analysis of dyadic deontic logics that were introduced in the early seventies to formalize deontic reasoning about subideal behavior. Recently it was observed that they are closely related to non-monotonic logics, theories of diagnosis and decision theories. In particular, we argue that two types of defeasibility must be distinguished in a defeasible deontic logic: overridden defeasibility that formalizes cancelling of an obligation by other conditional obligations and factual defeasibility that formalizes overshadowing of an obligation by a violation. We also show that this distinction is essential for an adequate analysis of notorious `paradoxes' of deontic logic such as the Chisholm and Forrester `Paradoxes'. http://repub.eur.nl/res/pub/456/ 1995-01-01T00:00:00Z There is a fundamental difference between a conditional obligation being violated by a fact, and a conditional obligation being overridden by another conditional obligation. In this paper we propose a multi preference semantics for a defeasible deontic logic that is based on this fundamental difference. The semantics contains one preference relation for ideality, which can be used to formalize deontic `paradoxes' like the Chisholm and Forrester `Paradoxes', and another preference relation for normality, which can be used to formalize exceptions. The interference of the two preference orderings generates new questions about preferential semantics. http://repub.eur.nl/res/pub/447/ 1994-01-01T00:00:00Z Deontic logic is characterized by the distinction between the actual and the ideal. In this article we discuss the situation where the actual deviates from the ideal, where obligations are violated. Nonmonotonic logics can be very helpful for the formalization of deontic reasoning, in particular to infer moral cues. It has been argued that the problems related to violated obligations, e.g. the Chisholm `Paradox', are just instances of problems of defeasible reasoning. We disagree with this claim since we will argue that there is a fundamental difference between a violated and a defeated obligation. In this article, we analyze violated obligations in Horty's nonmonotonic framework. We extend his definition of deontic consequence in such a way that it covers violated obligations and we give a solution to deal with conflicts between violability and defeasibility. http://repub.eur.nl/res/pub/1464/ 1993-01-01T00:00:00Z Inductive learning models [Plotkin 1971; Shapiro 1981] often use a search space of clauses, ordered by a generalization hierarchy. To find solutions in the model, search algorithms use different generalization and specialization operators. In this article we will decompose the quasi-ordering induced by logical implication into six increasingly weak orderings. The difference between two successive orderings will be small, and can therefore be understood easily. Using this decomposition, we will describe upward and downward refinement operators for all orderings, including $theta$-subsumption and logical implication.