Jan M. Broersen

The BOID architecture: conflicts between beliefs, obligations, intentions and desires

In this paper we introduce the so-called Beliefs-Obligations-Intentions-Desires or BOID architecture. It contains feedback loops to consider all effects of actions before committing to them, and mechanisms to resolve conflicts between the outputs of its four components. Agent types such as realistic or social agents correspond to specific types of conflict resolution embedded in the BOID archecture.

Designing a Deontic Logic of Deadlines

This paper studies the logic of a dyadic modal operator for being obliged to meet a condition ρ before a condition δ becomes true. Starting from basic intuitions we arrive at a simple semantics for deadline obligations in terms of branching time models. We show that this notion of deadline obligation can be characterized in the branching time logic CTL. The defined operator obeys intuitive logic properties, like monotony w.r.t. ρ and anti-monotony w.r.t. δ, and avoids some counter-intuitive properties like agglomeration w.r.t ρ and’weak agglomeration’ w.r.t. δ. However, obligations of this type are implied by the actual achievement of ρ before the deadline. We argue that this problem is caused by the fact that we model the obligation only from the point of view of its violation conditions. We show that the property might be eliminated by considering success conditions also.

A Complete STIT Logic for Knowledge and Action, and Some of Its Applications

This paper presents a complete temporal STIT logic for reasoning about multi-agency. I discuss its application for reasoning about norms, knowledge, autonomy, and other multi-agent concepts. Also I give some arguments in favor of taking STIT formalisms instead of dynamic logics as the basis for logics for representing multi-agent system notions.

Deontic epistemic stit logic distinguishing modes of mens rea

Abstract Most juridical systems contain the principle that an act is only unlawful if the agent conducting the act has a ‘guilty mind’ (‘mens rea’). Different law systems distinguish different modes of mens rea. For instance, American law distinguishes between ‘knowingly’ performing a criminal act, ‘recklessness’, ‘strict liability’, etc. This paper shows we can formalize several of these categories. The formalism used is a complete stit logic featuring operators for actions taking effect in next states, operators for S5-knowledge and operators for SDL-type obligation. The different modes of ‘mens rea’ correspond to the violation conditions of different types of obligation definable in the logic.

Meeting the deadline: why, when and how

This paper defines a possible semantics for deadline obligations. Also, we make explicit several choices to be made in defining the semantics of deadline obligations. We characterize deontic deadline operators in CTL, minimally extended with propositional violation constants. The advantage of this reduction approach is that formal reasoning can be performed in CTL.

Reasoning about Constitutive Norms, Counts-As Conditionals, Institutions, Deadlines and Violations

Reasoning about norms and time is of central concern to the regulation or control of the behavior of a multi-agent system. In earlier work we introduce a representation of normative systems that distinguishes between norms and the detached obligations of agents over time. In this paper we consider constitutive norms and the detached counts-as conditionals and institutional facts in this framework, we introduce deadlines in the regulative norms, and we consider the corresponding role of violations. We focus on the reasoning tasks to determine whether a constitutive or regulative norm is redundant in a normative system and whether two normative systems are equivalent. We distinguish counts-as equivalence, institutional equivalence, obligation equivalence and violation equivalence, depending on whether we are interested in all normative consequences, or only a subset of them. For the various notions of equivalence, we give sound and complete characterizations.

Knowledge Representation for Agents and Multi-Agent Systems

This book constitutes the thoroughly refereed post-workshop proceedings of the First International Workshop on Knowledge Representation for Agents and Multi-Agent Systems, KRAMAS 2008, held in Sydney, Australia, in September 2008 as a satellite event of KR 2008, the 11th International Conference on Principles of Knowledge Representation and Reasoning. The 10 revised full papers presented were carefully reviewed and selected from 14 submissions. The papers foster the cross-fertilization between the KR (knowledge representation and reasoning) and agent communities, by discussing knowledge representation theories and techniques for agent-based systems

Beliefs, obligations, intentions, and desires as components in an agent architecture

In this article we discuss how cognitive attitudes like beliefs, obligations, intentions, and desires can be represented as components with input/output functionality. We study how to break down an agent specification into a specification of individual components and a specification of their coordination. A typical property discussed at the individual component specification level is whether the input is included in the output, and a typical property discussed at the coordination level is whether beliefs override desires to ensure realism. At the individual level we show how proof rules of so‐called input/output logics correspond to properties of functionality descriptions, and at the coordination level we show how global constraints coordinating the components formalize coherence properties.

Resolving Conflicts between Beliefs, Obligations, Intentions, and Desires

This paper provides a logical analysis of conflicts between informational, motivational and deliberative attitudes such as beliefs, obligations, intentions, and desires. The contributions are twofold. First, conflict resolutions are classified based on agent types, and formalized in an extension of Reiters normal default logic. Second, several desiderata for conflict resolutions are introduced, discussed and tested on the logic. The results suggest that Reiters default logic is too strong, in the sense that a weaker notion of extension is needed to satisfy the desiderata.

Strategic deontic temporal logic as a reduction to ATL, with an application to chisholm's scenario

In this paper we extend earlier work on deontic deadlines in CTL to the framework of alternating time temporal logic (ATL). The resulting setting enables us to model several concepts discussed in the deontic logic literature. Among the issues discussed are: conditionality, ought implies can, deliberateness, settledness, achievement obligations versus maintenance obligations and deontic detachment. We motivate our framework by arguing for the importance of temporal order obligations, from the standpoint of agent theory as studied in computer science. In particular we will argue that in general achievement obligations cannot do without a deadline condition saying the achievement has to take place before it. Then we define our logic as a reduction to ATL. We demonstrate the applicability of the logic by discussing a possible solution to Chisholms paradox. The solution differs considerably from other known temporal approaches to the paradox.