J. Carmo and Andrew J. I. Jones.
Deontic database constraints, violation and recovery.
Studia Logica, to appear.

J. Carmo and Andrew J. I. Jones.
Deontic logic and different levels of ideality.
Technical Report REPORT RRDMIST1/95, Dept. of Mathematics, Technological University of Lisbon, 1995.

A. J. I. Jones and M. Sergot.
A formal characterisation of institutionalised power.
The Bulletin of the Interest Group in Pure and Applied Logics, 1995.

A. J. I. Jones.
Norm-governed systems: Some formal aspects.
In J. Bing and O. Torvund, editors, 25 Years Anthology - Norwegian Research Center for Computers and Law. Tano forlag, 1995.

H. Herrestad and C. Krogh.
Deontic logic relativised to bearers and counterparties.
In J. Bing and O. Torvund, editors, 25 Years Anthology - Norwegian Research Center for Computers and Law. Tano forlag, 1995.

H. Herrestad and C. Krogh.
Obligations directed from bearers to counterparties.
In Proceedings of the Fifth International Conference On Artificial Intelligence And Law. ACM Press, New York, May 1995.

C. Krogh.
Obligations in multiagent systems.
In The Proceedings of SCAI`95 (Scandinavian AI Conference). IOS Press, May 1995.

R.M. Lee and R. W. H. Bons.
Ai aspects of open electronic commerce.
In Proceedings of the Seventh Dutch AI Conference, NAIC-95, Rotterdam, The Netherlands, June 1995.

C. Krogh.
The rights of agents.
Technical Report AFIN 1995/2, Avd. for forvaltningsinformatikk, NRCCL, Univ.of Oslo, 1994.

P.d' Altan, J.-J. Ch. Meyer, and R.J. Wieringa.
An integrated framework for ought-to-be and ought-to-do constraints.
Technical Report IR-342, Vrije Universiteit, Amsterdam, December 1993.
submitted.

Khaled Al-Hazmi.
Step and the express language.
DAKE Centre Technical Report DAKE/-/TR-94017.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
PostScript

H. Andreka, M. D. Ryan, and P.-Y. Schobbens.
Operators and laws for combining preference relations.
In Wieringa and Feenstra .

Eric Dubois and Michael Petit.
The formal requirements engineering of manufacturing systems.
In S.M. Deen, editor, Proc. of the Second International Working Conference on Cooperative Knowledge Based Systems -- CKBS'94, pages 67--82, Keele (UK), June 14-17, 1994.
PostScript

Amedeo Cesta and Maria Miceli.
Situation assessment in help-seeking: Interaction strategies in multi-agent domains.
Technical Report TR-IP-PSCS-94-5, IP-CNR, May 1994.
Proceedings of the Second International Round Table on Abstract Intelligent Agent (AIA94), 1994.
Abstract
This work explores the factors that influence an agent's choice of a social strategy while looking for another's help. In previous work, agent behavior was explained in term of its ability of reasoning about others. In this paper, the behavior of the help-seeking agent is justified by its reasoning about others' capabilities and willingness. Three main help-seeking strategies are identified (exploitation, benevolence-seeking, and the offer of exchange) and several variables influencing the choice of a strategy are discussed.

Amedeo Cesta, Daniela D'Aloisi, and Vittorio Giannini.
Active interfaces for useful software tools.
In Y.Anzai and K.Ogawa, editors, Proceedings of the 6th Int. Conf. on Human-Computer Interaction, Yokohama, Japan, July 9-14, 1995. Elsevier Science, July 1995.
In press.
Abstract
The majority of public domain software tools is endowed with programmer-oriented interfaces and, as a consequence, they are mainly devoted to "hackers" or specialized programmers. This paper concerns the development of an active interface used to make the utilization of a free software for filtering e-mail messages easy. A multi-agent implementation of an interface is proposed that from one side allows the user to easily specify his needs and from another actively reasons on the user's choices to improve the performance of the filtering process.

S. Conrad.
Unterstützung des korrektheitszentrierten Entwurfs von Informationssystemen .
In G. Lausen, editor, Datenbanksysteme in Büro, Technik und Wissenschaft (BTW'95) . Springer-Verlag, 1995.
(in German).
PostScript

S. Conrad.
A Basic Calculus form verifying properties of Interacting Objects .
Internal Report , University of Magdeburg, 1995.
(submitted to a journal).
PostScript

R. Dieng, O. Corby, and S. Labidi.
Expertise C onflicts in K nowledge A cquisition.
In B. Gaines and M. Musen, editors, Proc. of the 8th International Workshop on Knowledge Acquisition for Knowledge-Based Systems (KAW'94), volume 2, pages 23-1--23-19, Banff, Canada, January - February 1994.

R. Dieng, O. Corby, and S. Labidi.
Agent- B ased K nowledge A cquisition.
In L. Steels, G. Schreiber, and W. Van de Velde, editors, A Future for Knowledge Acquisition: Proc. of the 8th European Knowledge Acquisition Workshop, EKAW'94, pages 63--82, Hoegaarden, Belgium, September 1994. Springer-Verlag.

F.P.M. Dignum, J.-J. Ch. Meyer, and R.J. Wieringa.
Free choice and contextually permitted actions.
Studia Logica, 1995.

Philippe Du Bois .
Intuitive definition of the Albert II language.
Technical report, Computer Science Department, University of Namur, Namur (Belgium), February 1995.

Philippe Du Bois .
Semantic definition of the Albert II language.
Technical report, Computer Science Department, University of Namur, Namur (Belgium), February 1995.

Eric Dubois, Philippe Du Bois , and Jean-Marc Zeippen.
A formal requirements engineering method for real-time, concurrent, and distributed systems.
In Proc. of ICSE-17 Workshop on Foraml Methods Applications in Software Engineering, Seattle WA, April 24-25, 1995.

S.M Deen(Editor).
Proc. of the 1993 ckbs-sig workshop, september 1993, 1994.
ISBN 0 9521789 1 5.
PostScript

S.M. Deen(Editor).
Proc. of the second international working conference on ckbs, june 1994, 1994.
ISBN 0 9521789 2 3.
PostScript

S.M. Deen.
Cooperation issues in holonic manufacturing systems.
In Proc. of the International Conference on Information Infrastructure Systems for Manufacturing, pages 401-412. Elsevier, 1994.
ISSN 0926 5481 : Also DAKE/-/TR940012.0.
PostScript

S.M. Deen.
A cooperation framework for holonic interactions in manufacturing.
In Proc. of the Second International Working Conference on CKBS, June 1994, pages 103-124. DAKE Centre, University of Keele, 1994.
ISBN 0 9521789 2 3 : Also DAKE/-/TR-940006.0.
PostScript

S.M. Deen.
An architectural framework for some ckbs applications.
DAKE Centre Technical Report DAKE/-/TR-94001.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
PostScript

S.M. Deen.
Systems characteristics of holons for intelligent manufacturing systems.
DAKE Centre Technical Report DAKE/-/TR-94003.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
PostScript

R. Dieng.
Agent- B ased M ethod for B uilding a C ooperative K nowledge- B ased S ystem.
In Proc. of the Fifth Generation Computer Systems 1994 (FGCS'94) Workshop on Heterogeneous Cooperative Knowledge-Bases, pages 237-251, Tokyo, Japan, dicembre 1994.

R. Dieng.
Specifying a C ooperative K nowledge- B ased S ystem through A gent- B ased A cquisition.
In B. Gaines and M. Musen, editors, Proc. of the 9th Banff Workshop on Knowledge Acquisition for Knowledge-Based Systems (KAW'95), volume 1, pages 20-1--20-20, Banff, Canada, February - March 1995.
Also in Proc. of the International Workshop on the Design of Cooperative Systems (COOP'95), Juan-les-Pins, January 1995, p. 141-160 .

R. Dieng.
Conflict management in K nowledge A cquisition.
Artificial Intelligence for Engineering Design, Analysis and Manufacturing (AIEDAM), Special Issue on Conflict Management in Design, Summer 1995.

J. Fiadeiro and T. Maibaum.
Verifying for reuse: Foundations of object-oriented system verification.
In C. Hankin, I. Makie, and R. Nagarajan, editors, Theory and Formal Methods 1994,. Springer-Verlag, 1995?
To be published.

C. Paredes and J. Fiadeiro.
Reuse of requirements and specifications -- a formal framework.
In Symposium on Software Reusability (SSR'95),. ACM, 1995.

J. Fiadeiro and T. Maibaum.
Interconnecting formalisms: supporting modularity, reuse and incrementality.
submitted.

J. Fiadeiro and J. F. Costa.
Institutions for behaviour specification.
In G. Reggio E. Astesiano and A. Tarlecki, editors, Recent Trends in Data Type Specification, number 906 in Lectures Notes in Computer Science. Springer-Verlag, 1995.

J. Fiadeiro and G. Reichwein.
A categorical theory of superposition.
Technical Report, presented at the 1st MEDICIS Workshop, Namur, December 1994.

U. Leonhardt, A. Finkelstein, J. Kramer, and B. Nuseibeh.
Decentralised process modelling in a multi-perspective development environment.
In Proceedings of 17th International Conference on Software Engineering (ICSE-17),. IEEE CS Press, April 1995.
To appear.

B. Nuseibeh, A. Finkelstein, and J. Kramer.
Method engineering for multi-perspective software development.
Information and Software Technology Journal, 1995.
to appear.

A. Finkelstein, D. Gabbay, A. Hunter, J. Kramer, and B. Nuseibeh.
Inconsistency handling in multi-perspective specifications.
Transactions on Software Engineering, 20(8):569-578, August 1994.

Martyn Fletcher and S.M. Deen.
Multi agent design issues in congestion management.
In S.M. Deen, editor, Proc. of the CKBS-SIG Workshop, Sept. 1993, pages 280-302. DAKE Centre, University of Keele, 1994.
ISBN 0 9521789 1 5 : Also DAKE/-/TR-940016.0.
PostScript

Martyn Fletcher.
A ckbs approach to dynamic network management.
DAKE Centre Poster DAKE/-/TR-94015.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, June 1994.
A poster presented at the Second International Working Conference on CKBS.
PostScript

Martyn Fletcher.
Orthogonal ckbs approaches to congestion management.
DAKE Centre Technical Report DAKE/-/TR-04004.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, August 1994.
Submitted to the Fourth International Conference on Computer Communications and Networks. Also registered as CS dept. technical report TR94-16.
PostScript

Martyn Fletcher.
Implementing an intelligent network routing model in a ckbs.
DAKE Centre Technical Report DAKE/-/TR-940014.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
PostScript

Martyn Fletcher.
A ckbs model of dynamic service management.
DAKE Centre Technical Report DAKE/-/TR-94011.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, December 1994.
Also registered as a CS dept. technical report TR95-02,ISSN 1353-7776.
PostScript

Th. Hartmann.
Spezifikation und Ausführung von Objektinteraktionen in TROLL .
In U. Lipeck and G. Vossen, editors, Workshop Formale Grundlagen für den Entwurf von Informationsystemen , pages 89--95. Technical Report 03/94, Pages 89-95, University of Hannover , 1994.
(in German).

Th. Hartmann and G. Saake.
Prototypische Ausführung von Objektinteraktionen für die Spezifikationssprache TROLL .
In F. Simon, editor, Workshop Deklarative Programmierung und Spezifikation , pages 56--59. Technical Report No. 9412, University of Kiel , 1994.
(in German).

Farhad Heidari.
Flexible manufacturing systems - an overview of progress in research and in practice.
DAKE Centre Technical Report DAKE/-/TR-94008.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
PostScript

Farhad Heidari.
Manufacturing intelligence - an overview of progress in research and in practice.
DAKE Centre Technical Report DAKE/-/TR-94007.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
PostScript

Farhad Heidari.
Issues in scheduling automated manufacturing systems.
DAKE Centre Technical Report DAKE/-/TR-94010.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
PostScript

Athula Herath.
Towards a ckbs model for holonic manufacturing environments.
DAKE Centre Technical Report DAKE/-/TR-94002.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, January 1994.
PostScript

Chris Johnson.
On the termination of clause graph resolution.
Journal of Automated Reasoning, 13:83-115, 1994.
PostScript

Chris Johnson.
A terminating variant of clause graph resolution.
DAKE Centre Technical Report DAKE/-/TR-94021.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
Submitted to the Springer Lecture Notes in Computer Science.
PostScript

Chris Johnson.
On computing the gcwa.
DAKE Centre Technical Report DAKE/-/TR-94018.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
Submitted to the Journal of Data and Knowledge Engineering.
PostScript

Chris Johnson.
Top down deduction in indefinite deductive databases.
DAKE Centre Technical Report DAKE/-/TR-94019.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
Submitted to the Journal of Automated Reasoning.
PostScript

Chris Johnson.
Deduction trees and the view update problem in indefinite deductive databases.
DAKE Centre Technical Report DAKE/-/TR-94020.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, 1994.
Submitted to the Journal of Automated Reasoning.
PostScript

J.-J. Ch. Meyer, F.P.M. Dignum, and R.J. Wieringa.
The paradoxes of deontic logic revisited: A computer science perspective.
Technical Report UU-CS-1994-38, Utrecht University, September 1994.

Maria Miceli, Amedeo Cesta, and Paola Rizzo.
Defining autonomous help in distributed work environments.
In Reinhard Oppermann, Sebastiano Bagnara, and David Benyon, editors, Proceedings of ECCE7, Seventh European Conference on Cognitive Ergonomics, pages 367--377. GMD, September 1994.
Abstract
This work tries to contribute from a multi-agent systems perspective to the studies aimed at describing and designing environments for cooperative work. In particular, it is aimed at specifying cognitive principles for a basic kind of behavior among autonomous members of organizations: helping behavior. Once introduced the main assumptions of our model of a cognitive and social agent, a basic definition of help is given and the conditions and motivations for either help-seeking and help-giving strategies are presented.

Maria Miceli, Amedeo Cesta, and Paola Rizzo.
Distributed artificial intelligence from a socio-cognitive standpoint: Looking at motivations for interaction.
Technical Report TR-IP-PSCS-95-1, IP-CNR, January 1995.
Submitted to Acta Psychologica Special Issue on Cognitive Ergonomics.
Abstract
Distributed Artificial Intelligence (DAI) deals with computational systems where several intelligent agents interact in a common environment. This paper is aimed at pointing out and fostering the exchange between DAI and cognitive and social sciences. An overview of DAI research is presented that stresses the social aspects of the field. A model of multi-agent interaction is also described which is motivated by requirements of cognitive plausibility and grounded on the notions of power, dependence and help. Connections with human-computer interaction are also suggested.

Baird Ndovie.
Multi-agent cooperation in air traffic control: A functional analysis.
DAKE Centre Technical Report DAKE/-/TR-940013.0, University of Keele, Dake Centre, University of Keele, Keele, Staffs ST5 5BG, UK, February 1994.
Also published in the IMAGINE Project Final Report.
PostScript

Baird Ndovie.
Simulation of a conflict management system for air traffic control.
In Proc. of the Second International Working Conference on CKBS, June 1994, pages 235-254. DAKE Centre, University of Keele, 1994.
ISBN 0 9521789 2 3 : Also DAKE/-/TR-940005.0.
PostScript

Paola Rizzo, Amedeo Cesta, and Maria Miceli.
Basic ingredients for modeling help-giving in multi-agent systems.
Technical Report TR-IP-PSCS-94-8, IP-CNR, September 1994.
also appeared in Draft Proceedings of the 2nd International Working Conference on Cooperative Knowledge Based Systems (CKBS94), Keele, UK, June 15-17.
Abstract
This paper concerns the helping behavior in multi-agent systems. Helping actions represent an interesting and rich testbed for examining the reasons for cooperative behavior in multi-agent systems. Initial work done for representing help is described along with a simple experimental environment.

Paola Rizzo, Amedeo Cesta, and Maria Miceli.
On helping behavior in cooperative systems.
In Proceedings of the International Workshop on the Design of Cooperative Systems (COOP-95). INRIA, 1995.
A previous version appeared as RIZ94.
Abstract
This paper concerns the helping behavior in multi-agent systems. Helping actions represent an interesting and rich testbed for examining the reasons for cooperative behavior in multi-agent systems. Starting from previous studies on multi-agent dependence relations, a basic definition of help is given, and some of the motivations for helping are briefly discussed. Moreover, an experimental environment for simulating agents that can perform helping behavior is described, and some preliminary results are presented.

M. D. Ryan and P.-Y. Schobbens.
Belief revision and verisimilitude.
Notre Dame Journal of Formal Logic, 1995.
In print.

M. D. Ryan, A. Sernadas, and C. Sernadas.
Adjunctions between default frameworks.
In Wieringa and Feenstra .

G. Saake, S. Conrad, and C. Türker.
From Object Specification towards Agent Design .
Internal Report , University of Magdeburg, 1995.
(submitted).
PostScript

G. Saake, A. Sernadas, and C. Sernadas.
Evolving Object Specifications .
In R. Wieringa and R. Feenstra, editors, Selected Papers of the Int. Workshop on Information Systems - Correctness and Reusability (IS-CORE'94) . World Scientific Publishing, 1995.
PostScript

P.-A. Tourtier and C. Amergi.
Toward H uman- C omputer C ollaboration.
In Proc. of the 6th Internation Conference on Human-Computer Interaction (HCI'95), Tokyo, Japan, July 1995.

P.-A. Tourtier.
A flexible facilitator-based cooperation framework.
In Proc. of the Fifth Generation Computer Systems 1994 (FGCS'94) Workshop on Heterogeneous Cooperative Knowledge-Bases, pages 101-110, Tokyo, Japan, december 1994.

Eric Yu, Philippe Du Bois , Eric Dubois, and John Mylopoulos.
From organization models to system requirements - a ``cooperating agents'' approach.
In Proc. of the Third International Conference on Cooperative Information Systems -- CoopIS-95, Vienna (Austria), May 9-12, 1995. University of Toronto Press inc.
PostScript

C. V. Damásio, W. Nejdl, L. Pereira, and M. Schroeder.
Model-based diagnosis preferences and strategies representation with meta logic programming.
In Krzysztof R. Apt and Franco Turini, editors, Meta-logics and Logic Programming. The MIT Press, 1995.

P.-Y. Schobbens.
Combining preferences requires hierarchies: An arrow theorem.
In Cees Witteveen, editor, Proceedings of Second Dutch/German Workshop on Non-Monotonic Reasoning. Utrecht University, March 1995.

Peter Fröhlich, Wolfgang Nejdl, and Michael Schröder.
A formal semantics for preferences and strategies in model-based diagnosis.
In International Workshop on Principles of Diagnoses, pages 106--113, New Paltz, NY, October 1994.

Peter Fröhlich, Wolfgang Nejdl, and Michael Schröder.
A formal semantics for preferences and strategies in model-based diagnosis.
In International Joint Conference on Artificial Intelligence, pages 106--113, Montreal, August 1995.

H. Prakken.
Argumentation with defeasible conditionals: a preliminary report (extended abstract).
Proceedings of Dutch/German Workshop on Non-Monotonic Reasoning, March 1995.

H. Prakken.
A semantic view on reasoning about priorities (extended abstract).
Proceedings of Dutch/German Workshop on Non-Monotonic Reasoning, March 1995.

H. Prakken.
From logic to dialectics in legal argument.
Proceedings of the Fifth International Conference on Artificial Intelligence and Law, Maryland, 1995.

H. Prakken.
Two approaches to the formalisation of defeasible deontic reasoning.
Studia Logica, 1995.

R. Wieringa and R. Feenstra, editors.
Information Systems: Correctness and Reuse.
World Scientific Publishing Co., 1995.

N.Barreiro, J.Fiadeiro, and T.Maibaum.
Politeness in object societies.
In R. Wieringa and R. Feenstra, editors, Information Systems: Correctness and Reuse. World Scientific Publishing Co., 1995.

J.Fiadeiro and T.Maibaum.
Sometimes 'tomorrow' is 'sometime': Action refinement in a temporal logic of objects.
In D.M.Gabbay and H.J.Ohlbach, editors, Temporal Logic, Lecture Notes in Artificial Intelligence 827, pages 48-66, 1994.

Gert-Jan Lokhorst.
Extensional deontic logics of action and their implementation.
In Proceedings of the second international workshop on deontic logic in computer science ($Delta$eon-94), Oslo, Norway, 1994.
An extended and revised version will appear in Studia Logica.

W. van der Hoek, B. van Linder, and J.-J. Ch. Meyer.
A logic of capabilities.
In A. Nerode and Yu.V. Matiyasevich, editors, Proceedings of the Third International Symposium on the Logical Foundations of Computer Science (LFCS'94), volume 813 of Lecture Notes in Computer Science, pages 366--378. Springer Verlag, 1994.

W. van der Hoek, B. van Linder, and J.-J. Ch. Meyer.
Unravelling nondeterminism: On having the ability to choose (extended abstract).
In P. Jorrand and V. Sgurev, editors, Proceedings of the Sixth International Conference on Artificial Intelligence: Methodology, Systems, Applications (AIMSA'94), pages 163--172. World Scientific, 1994.

B. van Linder, W. van der Hoek, and J.-J. Ch. Meyer.
Tests as epistemic updates.
In A.G. Cohn, editor, Proceedings of the 11th European Conference on Artificial Intelligence (ECAI'94), pages 331--335. John Wiley & Sons, 1994.

B. van Linder, W. van der Hoek, and J.-J. Ch. Meyer.
Tests as epistemic updates: Pursuit of knowledge.
Technical Report UU-CS-1994-08, Utrecht University, January 1994.

B. van Linder, W. van der Hoek, and J.-J. Ch. Meyer.
Communicating rational agents.
In B. Nebel and L. Dreschler-Fischer, editors, KI-94: Advances in Artificial Intelligence, volume 861 of Lecture Notes in Computer Science (subseries LNAI), pages 202--213. Springer Verlag, 1994.

B. van Linder, W. van der Hoek, and J.-J. Ch. Meyer.
The dynamics of default reasoning.
Technical Report UU-CS-1994-48, Utrecht University, October 1994.

B. van Linder, W. van der Hoek, and J.-J. Ch. Meyer.
Actions that make you change your mind: Belief revision in an agent-oriented setting.
Technical Report UU-CS-1994-53, Utrecht University, December 1994.

Wolfgang Nejdl and Martin Werner.
Distributed intelligent agents for control, diagnosis and repair.
Technical report, RWTH Aachen, August 1994.

H. Prakken and M.J.Sergot.
Contrary-to-duty obligations.
Studia Logica, 1995.

H. Prakken and G. Sartor.
On the relation between legal language and legal argument: assumptions, applicability and dynamic priorities.
Proceedings of the Fifth International Conference on Artificial Intelligence and Law, Maryland, 1995.

Y.-H. Tan J.-F. Raskin and L.W.N. van der Torre.
Modeling deontic states in petri nets.
In Proceedings of the Seventh Dutch AI Conference, NAIC-95, Rotterdam, The Netherlands, number WP 94.12.01, June 1995.

Y.-H. Tan and L.W.N. van der Torre.
Representing deontic reasoning in a diagnostic framework.
In Proceedings of the Workshop on Legal Applications of Logic Programming of the Eleventh International Conference on Logic Programming (ICLP'94), 1994.
An extended version of this paper will appear in the Journal of Artificial Intelligence and Law.

Y.-H. Tan and L.W.N. van der Torre.
Diode : D eontic logic based on diagnosis from first principles.
In Proceedings of the Workshop `Artificial normative reasoning' of the Eleventh European Conference on Artificial Intelligence (ECAI'94), Amsterdam, 1994.

Y.-H. Tan and L.W.N. van der Torre.
Multi preference semantics for a defeasible deontic logic.
In Proceedings of the JURIX'94, Amsterdam, 1994.

Y.-H. Tan and L.W.N. van der Torre.
Representing legal knowledge in a diagnostic framework.
Technical Report WP 94.12.02, Euridis , 1994.

Y.-H. Tan and L.W.N. van der Torre.
A diagnostic model for defeasible deontic logic.
In Proceedings of the European Conference on Symbolic and Quantitative Appraoches to Reasoning and Uncertainty (ECSQARU-95), 3--5 July 1995.

L.W.N. van der Torre.
Violated obligations in a defeasible deontic logic.
In Proceedings of the Eleventh European Conference on Artificial Intelligence (ECAI'94), pages 371--375. John Wiley $&$ Sons, 1994.

L.W.N. van der Torre and Y.-H. Tan.
Cancelling and overshadowing: two types of defeasibility in defeasible deontic logic.
Technical Report WP 95.02.01, Euridis , 1995.
To appear in: Proceedings of the IJCAI-95.