Collaborating Authors

Abstract Normative Systems: Semantics and Proof Theory

AAAI Conferences

In this paper we introduce an abstract theory of normative reasoning, whose central notion is the generation of obligations, permissions and institutional facts from conditional norms. We present various semantics and their proof systems. The theory can be used to classify and compare new candidates for standards of normative reasoning, and to explore more elaborate forms of normative reasoning than studied thus far.

Designing Normative Theories of Ethical Reasoning: Formal Framework, Methodology, and Tool Support Artificial Intelligence

The area of formal ethics is experiencing a shift from a unique or standard approach to normative reasoning, as exemplified by so-called standard deontic logic, to a variety of application-specific theories. However, the adequate handling of normative concepts such as obligation, permission, prohibition, and moral commitment is challenging, as illustrated by the notorious paradoxes of deontic logic. In this article we introduce an approach to design and evaluate theories of normative reasoning. In particular, we present a formal framework based on higher-order logic, a design methodology, and we discuss tool support. Moreover, we illustrate the approach using an example of an implementation, we demonstrate different ways of using it, and we discuss how the design of normative theories is now made accessible to non-specialist users and developers.

Automated Reasoning in Normative Detachment Structures with Ideal Conditions Artificial Intelligence

ARTICLE HISTORY Compiled October 24, 2018 ABSTRACT Systems of deontic logic suffer either from being too expressive and therefore hard to mechanize, or from being too simple to capture relevant aspects of normative reasoning. In this article we look for a suitable way in between: the automation of a simple logic of normative ideality and sub-ideality that is not affected by many deontic paradoxes and that is expressive enough to capture contrary-to-duty reasoning. We show that this logic is very useful to reason on normative scenarios from which one can extract a certain kind of argumentative structure, called a Normative Detachment Structure with Ideal Conditions. The theoretical analysis of the logic is accompanied by examples of automated reasoning on a concrete legal text. Keywords: Deontic Logic - Legal Reasoning - Normative Ideality 1. Introduction In the last decades, computer systems have played an important role in assisting people in a wide range of tasks, from searching over data to decision-making, and their use is required in an increasing number of fields. One of these fields is legal reasoning. New court cases and legislations are accumulated every day. In addition, international organizations like the European Union are constantly aiming at combining and integrating separate legal systems (Burley and Walter 1993).

Modeling Contrary-to-Duty with CP-nets Artificial Intelligence

Modelling deontic notions through preferences [12] has the advantage of linking deontic notions to the manifold research on preferences, in multiple disciplines, such as philosophy, mathematics, economics and politics. In recent years, preferences have also been addressed within AI [15,8,18] and applications can be found in multi-agent systems [19] and recommender systems [17]. We shall model deontic notions through ceteris-paribus preferences, namely, conditional preferences for a state of affairs over another state of affairs, all the rest being equal. In particular, we shall focus on the ceteris-paribus preference for a proposition over its complement. The idea of ceteris-paribus preferences was originally introduced by the philosopher and logician Georg von Wright [22].

Thou Shalt is not You Will Artificial Intelligence

The aim of this note is to discuss the reasons why temporal logic, specifically Linear Temporal Logic [7] might not be suitable to check whether the specifications of a system comply with a set of normative requirements. The debate whether it is possible to use temporal logic for the representation of norms is not a novel one (see for example [9]), and while the argument had settled for a while, the past decade saw a resurgence of the topic with many works in the fields of normative multi-agents and business process compliance advocating temporal logic as the formalism to express normative constraints on agent behaviours and process executions.