this paper was to address the role of deontic logic in legal knowledge representation. However, we now feel that this question cannot, and should not, be divorced from consideration of a much broader set of questions concerning the

Deontic logic is the logic that deals with actual as well as ideal behavior of systems. In this paper, we survey a number of applications of deontic logic in computer science that have arisen in the eighties, and give a systematic framework in which these applications can be classified. Many applications move in the direction of programming a computer in deontic logic to make the computer prohibit, permit or obligate people to do something. We discuss conditions under which this possibility is realistic and conditions under which it would be admissible to do so.

Distributed systems may be specified in Structured Modal Action Logic by decomposing them into agents which interact by sharing attributes (memory) as well as actions. In the formalism we describe, specification texts denote theories, and theories denote the set of semantic structures which satisfy them. The semantic structures are Kripke models, as is usual for modal logic. The "possible worlds" in a Kripke model are the states of the agent, and there is a separate relation on the set of states for each action term. Agents potentially share actions as well as attributes in a way controlled by locality annotations in the specification texts. These become locality axioms in the logical theories the texts denote. These locality axioms provide a refined way of circumscribing the effects of actions. Safety and liveness conditions are expressed (implicitly) by deontic axioms, which impose obligations and deny permissions on actions. We show that "deontic defaults" exist so that the specifi...

We present a logic for reasoning about licenses, which are “terms of use ” for digital resources. The logic provides a language for writing both properties of licenses and specifications that govern a client’s actions. We discuss the complexity of checking properties and specifications written in our logic and propose a technique for verification. A key feature of our approach is that it is essentially parameterized by the language in which the licenses are written, provided that this language can be given a trace-based semantics. We consider two license languages to illustrate this flexibility. 1

We give a semantics for lightweight UML class diagrams and ultra-lightweight statecharts in terms of labeled step transition systems that embody a minimal change, maximal step semantics, and in which changes generated in a step have effect in the following step. In order to define the semantics, we introduce dynamic step logic. 1 Introduction 1.1 Purpose In this paper we define a mixed formal specification language whose diagram syntax is a very simple subset of the UML syntax [27] and whose textual syntax is a version of ordersorted dynamic logic. We refer to this language as ultra-lightweight UML (ultra-LUML). The visual part of ultra-LUML consists of ultra-leightweight class diagrams (ultra-LCDs), which declare the decomposition of the system into objects, and of extended Mealy state diagrams (EMDs), which define object behavior. The textual part of utra-LUML is a version of dynamic logic and can be used to write a specification that is equivalent to a diagrammatic specificati...

The logic of norms, called deontic logic, has been used to specify normative constraints for information systems. For example, one can specify in deontic logic the constraints that a book borrowed from a library should be returned within three weeks, and that if it is not returned, the library should send a reminder. Thus, the notion of obligation to perform an action arises naturally in system specification.

this paper and we take it up again in the discussion at the end of this paper

: Traditional logic-based specification approaches fix the structure and the dynamics of an object system at specification time. Information systems are applications with a very long life-time. Therefore, object and specification evolution is needed to react to changing requirements. Hence, this is a relevant aspect of describing information systems as object societies. We present a logical specification framework for evolving objects. Our framework is based on the concepts of object developed for the languages Troll and Gnome and the underlying temporal logic OSL. The syntactic notion of object descriptions is extended to explicitly manipulate temporal axioms during behaviour evolution. An extension of OSL called dyOSL establishes a logical framework where basic temporal formulae are evaluated by a second logical layer. dyOSL allows to explicitly manipulate state-dependent sets of temporal formulae to model evolution of object axioms. 199 200 LOGICS FOR DATABASES AND INF...

. We propose a modular approach to the formal specication of the requirements on embedded systems. In this approach, requirements on data are specied as invariants on states. Requirements on behaviour are specied assertionally by temporal logic formulae, restricting the runs of the system. The proposed method is modular, because components can be specied and analysed in isolation, and the views of several components can be combined in an easy way. Requirements can be combined by simply putting them in conjunction. A mathematical framework supporting this approach is developed and implemented in the theorem prover PVS. The method is illustrated by formalising the requirements of a miniature embedded system. This specication is then analysed using the theorem prover, revealing some errors in the original specication. Keywords: formal requirements specication, embedded systems, modularity, data and behaviour, states and events, linear temporal logic, PVS. 1 Introduction The requir...

Abstract. The complete specification of full contracts — contracts which include tolerated exceptions, and which enable reasoning about the contracts themselves, can be achieved using a combination of temporal and deontic concepts. In this paper we discuss the challenges in combining deontic and other relevant logics, in particular focusing on operators for choice, obligations over sequences, contrary-to-duty obligations, and how internal and external decisions may be incorporated in an action-based language for specifying contracts. We provide different viable interpretations and approaches for the development of such a sound logic and outline challenges for the future. 1