Desires, norms and constraints

This paper deals with modeling mental states of a rational agent, in particular states based on agent’s desires. It shows that the world the agent belongs to forces it to restrict its desires. More precisely, desires of a rational agent are restricted by the constraints that exist in the world and which express what is possible or necessary. Furthermore, if the agent is law-abiding, its desires are restricted by the regulations that are defined in the world and which express what is obligatory, permitted or forbidden. This paper characterizes how desires are restricted depending on the fact that the agent is law-abiding or not. This work considers the general case when the agent orders its own desires according to a preference order. The solution is based on modeling desires, regulations and constraints in an unique formal system which is a logic of conditional preferences

Deriving individual obligations from collective obligations

A collective obligation is an obligation directed to a group of agents so that the group, as a whole, is obliged to achieve a given task. The problem investigated here is the impact of collective obligations on individual obligations,i.e. obligations directed to single agents of the group. In this case, we claim that the derivation of individual obligations from collective obligations depends on several parameters among which the ability of the agents (i.e. what they can do) and their own personal commitments (i.e. what they are determined to do). As for checking if these obligations are fulfilled or not, we need to know what are the actual actions performed by the agents

Distribution of goals addressed to a group of agents

The problem investigated in this paper is the distribution of goals addressed to a group of rational agents. Those agents are characterized by their ability (i.e. what they can do), their knowledge about the world and their commitments. The goals of the group are represented by conditional preferences. In order to deduce the actual goals of the group, we determine its ability using each agent’s ability and we suppose that the agents share a common knowledge about the world. The individual goals of an agent are deduced using its ability, the knowledge it has about the world, its own commitments and the commitments of the other agents of the group

A modal logic for reasoning on consistency and completeness of regulations

In this paper, we deal with regulations that may exist in multi-agent systems in order to regulate agent behaviour and we discuss two properties of regulations, that is consistency and completeness. After defining what consistency and completeness mean, we propose a way to consistently complete incomplete regulations. In this contribution, we extend previous works and we consider that regulations are expressed in a first order modal deontic logic

How to Complete Regulations in Multi-agent Systems

In this paper, we deal with regulations that may exist in multiagent systems in order to regulate agent behaviour. More precisely, we discuss two properties of regulations, consistency and ompleteness. After defining what consistency and completeness mean, we propose a way to consistently complete incomplete regulations. This contribution considers that regulations are expressed in a first order deontic logic. We will focus on particular regulations: information exchange policies

Answering queries addressed to several databases according to a majority approach

The general context of this work is the problem of merging data provided by several sources which can be contradictory. Focusing on the case when the information sources do not contain any disjunction, this paper first defines a propositional modal logic for reasoning with data obtained by merging several information sources according to a majority approach. Then it defines a theorem prover to automatically deduce these merged data. Finally, it shows how to use this prover to implement a query evaluator which answers queries adressed to several databases. This evaluator is such that the answer to a query is the one that could be computed by a classical evaluator if the query was adressed to the merged databases. The databases we consider are made of an extensional part, i.e. a set of positive or negative ground literals, and an intensional part i.e. a set of first order function-free clauses. A restriction is imposed to these databases in order to avoid disjunctive data

A logic to reason on contradictory beliefs with a majority approach

The context of this paper is the problem of merging data provided by several information sources, which can be contradictory. It takes as a starting point, one of the majority merging operators that Konieczny and Pino-Perez have defined [ KPP98] , [ KPP99]. In these papers, the authors have characterized, from a semantical point of view, some majority merging operators. The aim of our work is to define a logical calculus which corresponds to one of these operators. This paper focuses on the case when the information sources are sets of literals. It presents a logic which is sound and complete for some interesting kind of formulas and an associated theorem prover

Collective obligations, commitments and individual obligations: a preliminary study

A collective obligation is an obligation directed to a group of agents so that the group, as a whole, is obliged to achieve a given task. The problem investigated here is to study the impact of collective obligations to individual obligations, i.e. obligations directed to single agents of the group. The groups we consider do not have any particular hierarchical structure nor have an institutionalized representative agent. In this case, we claim that the derivation of individual obligations from collective obligations depends on several parameters among which the ability of the agents (i.e. what they can do) and their own personal commitments (i.e. what they are determined to do). As for checking if these obligations are fulfilled or not, we need to know what are the actual actions performed by the agents. This present paper addresses these questions in the rather general case when the collective obligations are conditional ones

Exigences, réglementations et contraintes

Cet article s'intéresse à la modélisation des exigences et à l'expression de leur compatibilité avec une réglementation et des contraintes du domaine. Nous nous plaçons dans le cas où les exigences sont ordonnées selon un ordre de priorité. Le problème est alors de déterminer, parmi les exigences ordonnées de l'agent, les plus préférées qui sont compatibles avec la réglementation et avec les contraintes du domaine. Pour cela, nous proposons de modéliser les exigences, les réglementations et les contraintes dans un cadre formel unique, une logique de préférences conditionnelles. Le choix d'un formalisme unique nous permet de donner une caractérisation simple des meilleures exigences compatibles avec la réglementation et les contraintes

Allocation des buts affectés à un groupe d'agents

Dans ce travail, nous présentons un formalisme permettant de déterminer, à partir des buts assignés à un ensemble d'agents et d'une représentation des agents, les buts individuels de chaque agent du groupe. Pour cela, nous utilisons CO*,une logique de préférences conditionnelles développée par Craig Boutilier. Nous étendons CO* et les notions développées par Boutilier au cas multi-agents