Table Of ContentLecture Notes in Artificial Intelligence 838
Subseries of Lecture Notes in Computer Science
Edited by .J .G Carbonell and .J Siekmann
Lecture Notes in Computer Science
Edited by .G Goos and .J Hartmanis
Craig MacNish David Pearce
Lufs Moniz Pereira (Eds.)
Logic s i" n
Artificial Intelligence
European Workshop JELIA '94
,kroY ,KU September 5-8, 4991
Proceedings
galreV-regnirpS
Berlin Heidelberg NewYork
London Paris Tokyo
Hong Kong Barcelona
Budapest
Series Editors
Jaime G. Carbonell
School of Computer Science, Carnegie Mellon University
Schenley Park, Pittsburgh, PA 15213-3890, USA
J6rg Siekmann
University of Saarland
German Research Center for Artificial Intelligence (DFKI)
Stublsatzenhausweg 3, D-66123 Saarbrticken, Germany
Volume Editors
Craig MacNish
Department of Computer Science, University of York
York YO1 5DD, England
David Pearce
LWI, Institut fiir Philosophie, Freie Universit~it Berlin
Habelschwerdter Allee 30, D- 14195 Berlin, Germany
Lufs Moniz Pereira
Departamento de Informatica, Universidade Nova de Lisboa
2825 Monte da Caparica, Portugal
CR Subject Classification (1991): 1.2, E3-4
ISBN 3-540-58332-7 Springer-Verlag Berlin Heidelberg New York
ISBN 0-387-58332-7 Springer-Verlag New York Berlin Heidelberg
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Preface
Logics have, for many years, laid claim to providing a formal basis for the study
of artificial intelligence. With the depth and maturity of formalisms and method-
ologies available today, this claim is stronger than ever.
The European Workshops on Logics in AI (or Journges Europ~ennes sur la
Logique en Intelligence Artificielle -- JELIA) began in response to the need
for a European forum for discussion of emerging work in this growing field.
JELIA'94 follows previous Workshops held in Roscoff, France (1988), Amster-
dam, the Netherlands (1990), and Berlin, Germany (1992).
JELIA'94 is taking place in York, England, from 5-8 September, 1994. The
Workshop is hosted by the Intelligent Systems Group in the Department of
Computer Science at the University of York. Additional sponsorship for the
1994 Workshop is provided by the ESPRIT NOE COMPULOG-NET, ACM
SIGART, the Association for Logic Programming--UK Branch (ALP-UK) and
the German Informatics Society (GI).
This volume contains the papers selected for presentation at the Workshop
along with papers and abstracts from the invited speakers. The increasing im-
portance of the subject was reflected in the submission of 97 papers, from which
24 were selected. Each paper was reviewed by at least 3 referees. We would like
to thank all authors and invited speakers for their contributions.
Organisation of the Workshop and the selection of papers was carried out
by the Organising Committee consisting of Craig MacNish (Workshop Chair),
David Pearce (Programme Co-chair) and Luis Moniz Pereira (Programme Co-
chair) together with the Programme Committee consisting additionally of Carlo
Cellucci, Luis Farinas del Cerro, Phan Minh Dung, Jan van Eijck, Patrice Enjal-
bert, Ulrich Furbach, Dov Gabbay, Antony Galton, Michael Gelfond, Vladimir
Lifschitz, Victor Marek, Bernhard Nebel, Wolfgang Nejdl and Hans Rott.
Further help in reviewing papers was provided by the additional referees
listed overleaf. We would like to extend our thanks to all referees for their valu-
able assistance.
We would also like to thank the Departments of Computer Science at the
University of York, England and Universidade Nova de Lisboa, portugal, for the
provision of facilities, and Antonis Kaniclides and Karen Mews for help with the
organisation of the Workshop. Finally ew would like to thank JSrg Siekmann,
Alfred Hofmann and Springer-Verlag for their assistance in the production of
this volume.
June 1994 Craig MacNish
Lufs Moniz Pereira
David Pearce
y
Additional Referees
J. Alferes Y. Arambulchai N. Asher
J. Bahsoun P. Balbiani P. Baumgartner
B. Bennett P. Bieber G. Brewka
K. Broda H. Biirckert M. Cayrol
A. Chandrabose P. Cholewinski F. Clerin-Debart
F. Cuppens R. Demolombe J. Dix
D. Duffy K. E1-Hindi B. Fronhoefer
C. Gabriella O. Gasquet E. Giunehiglia
J. Gooday M. Grosse A. Herzig
R. Hirsh J. Jaspars Y. Jiang
D. Keen M. Kerber C. Kreitz
G. Lakemeyer R. Letz R. Li
J. Lonsdale P. Mancarella N. McCain
W. Meyer Viol A. Mikitiuk L. Monteiro
A. Narayanan G. Neelakantan Kartha W. Nutt
C. Paulin-Mohring H. Prakken A. Porto
W. Reif M. Reynolds M. de Rijke
H. Ruess K. Schild C. Schwind
F. Stolzenburg M. Strecker M. Truszczynski
H. Turner I. Urbas M. Varga von Kibed
Y. Venema G. Wagner E. Weydert
Contents
Invited Speaker
From Carnap's Modal Logic to Autoepistemic Logic ......................
.G Gottlob
Nonmonotonic Reasoning
Compactness Properties of Nonmonotonic Inference Operations .......... 19
H. Herre
Around a Powerful Property of Circumscriptions ......................... 34
Y. Moinard and R. Rolland
The Computational Value of Joint Consistency ........................... 50
Y. Dimopoulos
Belief Revision
Belief Dynamics, Abduction, and Databases .............................. 66
.C Aravindan and P. M. Dung
On the Logic of Theory Base Change .................................... 86
M.-A. Williams
Logic Programming and Theory Revision
Belief, Provability, and Logic Programs .................................. 106
J. J. Alferes and L. M. Pereira
Revision Specifications by Means of Programs ............................ 122
.V W. Marek and M. Truszczydski
Revision of Non-Monotonic Theories: Some Postulates and
an Application to Logic Programming .................................... 137
.C Witteveen, W. van der Hoek and H. de Nivelle
Automated Reasoning
A Complete Connection Calculus with Rigid E-Unification ............... 152
.U Petermann
Equality and Constrained Resolution ..................................... 167
R. Scherl
IIIV
Efficient Strategies for Automated Reasoning in Modal Logics ............ 182
S. Demri
TAS-D++: Syntactic Trees Transformations for Automated
Theorem Proving ........................................................ 198
.G Aguilera, L P. de Guzmdn and M. Ojeda
A Unification of Ordering Refinements of Resolution in
Classical Logic ........................................................... 217
H. de Nivelle
Invited Speaker
Two Logical Dimensions (Abstract) ...................................... 231
E. Orlowska
Prloritized Nonmonotonic Reasoning
Prioritized Autoepistemic Logic ...................... .................... 232
J. Rintanen
Adding Priorities and Specificity to Default Logic ........................ 247
.G Brewka
Viewing Hypothesis Theories as Constrained Graded Theories ............ 261
P. Chatalic
Models of Reasoning
Temporal Theories of Reasoning ......................................... 279
J. Engelfriet and J. Treur
Reasoning about Knowledge on Computation Trees ...................... 300
K. Georgatos
Knowledge Representation
Propositional State Event Logic .......................................... 316
.G Grofle
Description Logics with Inverse Roles, Functional Restrictions,
and N-ary Relations ..................................................... 332
.G De Giacomo and M. Lenzerini
On the Concept of Generic Object: A Nonmonotonic Reasoning
Approach and Examples ................................................. 347
L. E. Bertossi and R. Reiter
(cid:141)I
Invited Speaker
Autoepistemic Logic of Minima Beliefs (Abstract) ....................... 364
T. .C Przymusinski
Extending Logic Programming
How to Use Modalities and. Sorts in Prolog ............................... 563
A. Nonnengart
Towards Resource Handling in Logic Programming:
the PPL Framework and its Semantics ................................... 973
J.-M. Jacquet and L. Monteiro
Extending Horn Clause Theories by Reflection Principles ................. 004
.S Costantini, P. Dell'Acqua and .G A. Lanzarone
From Carnap's Modal Logic to Autoepistemic
*cigoL
Georg Gottlob
Institut ffir Informationssysteme
Technische Universitgt Wien
Paniglgasse ,61 A-1040 Wien, Austria;
Internet: gottlob~vexpert, dbai. tuwien, ac. at
Abstract. In his treatise Meaning and Necessity, Carnap introduced an
original approach to modal logic which is quite different from the well-
known Lewis systems. Recently, it turned out that there are interesting
connections between Carnap's modal logic and finite model theory for
modal logics. In addition, Carnap's logic has applications in the field
of epistemic reasoning. It was also shown that formulas of Carnap's lo-
gic are structurally equivalent to trees of NP queries, more precisely,
of satisfiability tests. In this paper, we give a survey of these results.
Moreover, we extend Carnap's logic in a natural way by the possibility
of deriving consequences from nonmodal theories and show that the re-
sulting formalism is nonmonotonic. Finally, we explain the relationship
between Carnap's logic and autoepistemic logic and show that autoepi-
stemic reasoning corresponds to solving problems equivalent to (possibly
cyclic) graphs of interdependent NP queries.
1 Carnap's Modal Logic
In 1947 the philosopher and logician Rudolf Carnap published "Meaning and
Necessity", a study containing a new approach to semantics and modal logic
3. In particular, Carnap presents a new modal logic that differs substantial-
ly from the former Lewis systems. While Carnap's approach conveys both new
semantics for propositional modal sentences and an innovative treatment of in-
dividual variables in the first order case (the latter having been fruitfully applied
to axiomatizing parts of physics; cf. 1), we restrict our attention to the propo-
sitional part. The presentation of Carnap's logic here differs from the original
presentation in 3. Moreover, we use different (but equivalent) definitions.
Carnap's modal logic, which we will call C here 2 extends the classical pro-
positional calculus by a necessity operator and a possibility operator O. The
* This work was done in the context of the Christian Doppler Laboratory for Expert
Systems. Some of the results of the present paper were also presented in 10. A
journal version, integrating the results of 10 and most of the results of the present
paper is available from the author.
2 It is called $2 in 3 but that name may create confusion with the standard $2 system
of modal logic.
syntax of C formulas is the same as that of formulas in standard systems of pro-
positional modal logic (see, e.g. 15 or 4). Let us write ~-C r if formula r is valid
in logic C. The semantics of C is best described by giving a formal definition of
~-C" If r is a modal formula, then let modsub(r denote the set of all subformulas
of b~ of the form 0r or Or that occur in r at least at one place not being in the
scope of any 0 or O operator. For instance, if r = (OD(p) V O(DqA Dr)) --. Dr
then modsub(r contains the three formulas OD(p), D(Dq A Dr), and Dr.
Let r be a modal formula and let r E modsub(r A strict occurrence of r
in r is an occurrence of r which is not in the scope of a modal operator.
Definition 1.1 Validity in logic C si inductively defined sa follows.
- g r = nr then bC r ig Pc r
- g r = r>< hen PC r iF -'r
In lla other eases, C-~ r life + is valid in classical proposilional logic, where
r is the formula resulting from r yb replacing each strict occurrence of a
subformula r e modsub(r yb T if ~ r and yb k_ otherwise.
Intuitively, D can be considered as a strong provability operator that expres-
ses the metapredicate ~-C within the object language. De is valid (and provable)
if r is provable. On the other hand, if r is not provable, then --fie is valid (and
provable). Accordingly, in Carnap's logic each modal formula r of type 0r or
Or is determinate; i.e., it either holds that C-~ r or that ~-C "r Examples
of valid formulas of C are Op, O--p, -~Dp, Dq +-- Dr. Note that these formulas
are not valid in any standard system of modal logic. Familiar substitutivity laws
do not hold for C. For instance, we have ~C Op, but not C-~ (>(q A --q) even
though the second formula is obtained from the first by uniformly substituting
the formula q A -,q for the propositional variable p. Note that in Carnap's logic
C, as in most other modal logics, a formula of the form <)r is in all effects
equivalent to the formula -,0-,r so that we may build C entirely on the modal
operator defining >( as a shorthand for -,D-,. Vice versa, one may construct
C based on O and defining 0 as a shorthand for -,O'-.
Due to the failure of familiar substitutivity laws, Carnap's modal logic did
not give rise to much interest until recently. However, very recently Halpern and
Kapron have shown that there is an interesting connection between logic C and
0-l-laws for other modal logic.
The 0-l-law for predicate logic ,8 6 states that every property definable
without function symbols is either true with probability 1 (almost surely true)
or false with probability 1 (almost surely false) on finite structures. Analogous
0-l-laws for various propositional modal logics have recently been established
and studied by Halpern and Kapron 11.
Let S be a system of modal logic which is semantically characterized by
a corresponding class of Kripke-structures (S-structures). For any modal for-
mula r let uns(r express the ratio between the number of S-structures with
state-space {1,..., n} satisfying r over the number of all S-structures with sta-
te space {1,...,n}. (For a more precise definition of uS(e) refer to 11.) Let
~,s(r = limn-.oo us(c). Thus us(e) expresses the asymptotic probability that
