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Intelligent agents have an agenda that is monitored continuously to decide what action is to be performed. Formally, an agenda is a set of deontic temporal constraints. Deontic, since the agenda specifies what the agent should do. Temporal, since the obligation is usually to be performed before a certain deadline, or as soon as possible. In this paper, we investigate the concepts necessary to describe deadlines. We describe a temporal deontic logic that facilitates reasoning about obligations and deadlines. The logic is a combination of temporal logic and deontic dynamic logic. We describe extensively which choices have to be made in combining temporal and dynamic aspects into one system. In the new logic, we can uniformally specify that an obligation starts at a certain time or event, that it must be done immediately, as soon as possible, before a deadline, or periodically. 1 Introduction It is not very difficult to develop a program that checks whether deadlines are met. The main id...

The concept of an agent is increasingly used in contemporary software applications, particularly those involving the Internet, autonomous systems, or cooperation. However, with dependability and safety in mind, it is vital that the mechanisms for representing and implementing agents are clear and consistent. Hence there has been a strong research effort directed at using formal logic as the basis for agent descriptions and agent implementation. Such a logical basis not only presents the clarity and consistency required but also allows for important techniques such as logical verification to be applied. We present a roadmap of research into the use of computational logic in agent-based systems and survey much of the recent work in these areas. Even though, with such a rapidly changing field, it is impossible to cover every development, we aim to give the reader sufficient background to understand the current research problems and potential future developments in this maturing area.

This paper provides the reader with a presentation of preference modelling fundamental notions as well as some recent results in this field. Preference modelling is an inevitable step in a variety of fields: economy, sociology, psychology, mathematical programming, even medicine, archaeology, and obviously decision analysis. Our notation and some basic definitions, such as those of binary relation, properties and ordered sets, are presented at the beginning of the paper. We start by discussing different reasons for constructing a model or preference. We then go through a number of issues that influence the construction of preference models. Different formalisations besides classical logic such as fuzzy sets and non-classical logics become necessary. We then present different types of preference structures reflecting the behavior of a decision-maker: classical, extended and valued ones. It is relevant to have a numerical representation of preferences: functional representations, value functions. The concepts of thresholds and minimal representation are also introduced in this section. In section 7, we briefly explore the concept of deontic logic (logic of preference) and other formalisms associated with "compact representation of preferences " introduced for special purposes. We end the paper with some concluding remarks.

. In this paper, we describe a temporal deontic logic that facilitates reasoning about obligations and deadlines. The logic is an extension of deontic dynamic logic, in which only immediate obligations can be specified. In our extension, we can also specify that an obligation starts at a certain time or event, that it must be done immediately, as soon as possible, before a deadline, or periodically. A practical application area are intelligent agents that must be able to reason about their agendas. 1 Introduction It is not very difficult to develop a program that checks whether deadlines are met. The main idea is to wait until the deadline has passed, which usely can be checked easily, and then check whether a certain action has taken place. However, many difficulties arise when one tries to transform this procedural account of deadlines into a formal one. In an intelligent system (or agent) one would like to be able to reason about this type of constraints in order to check whether t...

In this paper we introduce some new operators into our framework that make it possible to reason about decisions and commitments to do actions. In our framework, a decision leads to an intention to do an action. The decision in itself does not change the state of the world, but only the relation to possible future worls. A commitment to actually perform the intended action changes the deontic state of the world such that the intended action becomes obligated. Of course, the obligated action may never actually occur. In our semantic structure, we use static (ought-to-be) and dynamic (ought-to-do) obligation operators. The static operator resembles the classical conception of obligation as truth in ideal worlds, except that it takes the current state as well as the past history of the world into account. This is necessary because it allows us to compare the way a state is actually reached with the way we committed ourselves to reach it. We show that some situations that cou...

Abstract. If we are to take the notion of speech act seriously, we must be able to treat speech acts as acts. In this paper, we will try to model changes brought about by various acts of commanding in terms of a variant of update logic. We will combine a multi-agent variant of the language of monadic deontic logic with a dynamic language to talk about the situations before and after the issuance of commands, and the commands that link those situations. Although the resulting logic inherits various inadequacies from monadic deontic logic, some interesting principles are captured and seen to be valid nonetheless. A complete axiomatization and some interesting valid principles together with concrete examples will be presented, and suggestions for further research will be made. 1

We consider the problem of checking whether the operations of an organization conform to a body of regulation. The immediate motivation comes from the analysis of the U.S. Food and Drug Administration regulations that apply to bloodbanks- organizations that collect, process, store, and use donations of blood and blood components. Statements in such regulations convey constraints on operations or sequences of operations that are performed by an organization. It is natural to express these constraints in a temporal logic. There are two important features of regulatory texts that need to be accommodated by a representation in logic. First, the constraints conveyed by regulation can be obligatory (required) or permitted (optional). Second, statements in regulation refer to others for conditions or exceptions. An organization conforms to a body of regulation if and only if it satisfies all the obligations. However, permissions provide exceptions to obligations, indirectly affecting conformance. In this paper, we extend linear temporal logic to distinguish between obligations and permissions, and to allow statements to refer to others. While the resulting logic allows for a direct representation of regulation, evaluating references between statements has high complexity. We discuss an empirically motivated assumption that lets us replace references with tests of lower complexity, leading to efficient trace-checking algorithms in practice.

A generic architecture for autonomous agents is presented. In common with other current proposals the agent is capable of reacting to and reasoning about events which occur in its environment, execute actions and plans in order to achieve goals in its environment, and communicate with other agents. The work described here proposes certain advances on other systems, notably the ability to reason about and make decisions under uncertainty, including decisions about competing beliefs and alternative actions. The framework is grounded in a non-classical decision model, the 'domino' model. This is formalised to ensure continuity with classical decision theory and avoid ad hoc features. The domino model is embodied in a well-defined knowledge representation language, R 2 L, which explicitly supports the central concepts of decisions and plans, and associated constructs of goals, arguments, commitments, obligations and constraints. The availability of such a language provides a sound basis ...

Abstract. We explain the raison d’être and basic ideas of our gametheoretic approach to normative multiagent systems, sketching the central elements with pointers to other publications for detailed developments.