Rwth Aachen, Lufg Theoretische Informatik, Ian Horrocks, Ulrike Sattler, Stephan Tobies
ALCNaugmented with transitive and inverse roles---is an expressive Description Logic which is especially well-suited for the representation of complex, aggregated objects. Despite its expressiveness,...
Sergio Antoy, Yoshihito Toyama (eds, Aachener Informatik Berichte, Rwth Aachen
Autowrite is an experimental software tool written in Common Lisp for handling term rewrite systems and bottom-up tree automata. A graphical interface has been written using McCLIM, (the free...
WST'04 7th International Workshop on Termination (2004)
Michael Codish, Aart Middeldorp (eds, Aachener Informatik Berichte, Rwth Aachen
Partial Evaluation for Termination Analysis . . . . . . . . . . . . . . . . . . . . . 47 Lior Tamary, Michael Codish Relative Termination in Term Rewriting . . . . . . . . . . . . . . . . . . . . . ....
Sergio Antoy, Yoshihito Toyama (eds, Aachener Informatik Berichte, Rwth Aachen
Autowrite is an experimental software tool written in Common Lisp for handling term rewrite systems and bottom-up tree automata. A graphical interface has been written using McCLIM, (the free...
Message-Passing Automata are expressively equivalent to EMSO logic (2004)
Martin Leucker, Aachener Informatik Berichte, Rwth Aachen, Benedikt Bollig
We study the expressiveness of finite message-passing automata with a priori unbounded channels and show them to capture exactly the class of MSC languages that are definable in existential monadic...
Mechanizing Dependency Pairs (2003)
Aachener Informatik Berichte, Rwth Aachen, Jurgen Giesl, Rene Thiemann, Peter Schneider-kamp, Stephan Falke
The dependency pair approach [2, 13, 14] is a powerful technique for automated termination and innermost termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality...
Extending DTGOLOG with Options (2003)
A. Ferrein, Ch. Fritz, G. Lakemeyer, Rwth Aachen
Introduction Recently Boutilier et al. (2000) proposed the language DTGOLOG which combines explicit agent programming with decision theory. The motivation is that a user often has some idea about how...
Deepak Kapur, Aachener Informatik Berichte, Rwth Aachen, Jurgen Giesl
Kapur and Subramaniam [11] defined syntactical classes of equations where inductive validity can be decided automatically. However, these classes are quite restrictive, since defined function symbols...
An Existential Fragment of Second Order Logic (2003)
Eric Rosen, Mathematische Grundlagen Der Informatik, Rwth Aachen
this paper, we examine an existential fragment of second order logic. In particular, we are interested in analyzing the expressive power of this logic over the class of finite structures. Thus, this...
Improving Dependency Pairs (2003)
Aachener Informatik Berichte, Rwth Aachen, Jurgen Giesl, Rene Thiemann, Peter Schneider-kamp, Stephan Falke
The dependency pair approach [2, 12, 13] is one of the most powerful techniques for termination and innermost termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality...
Improving Dependency Pairs (2003)
Aachener Informatik Berichte, Rwth Aachen, Jurgen Giesl, Rene Thiemann, Peter Schneider-kamp, Stephan Falke
The dependency pair approach [2, 11, 12] is one of the most powerful techniques for termination and innermost termination proofs of term rewrite systems (TRSs). For any TRS, it generates inequality...
Solving the Sabotage Game is PSPACE-hard (2003)
We consider the sabotage game presented by van Benthem in an essay on the occasion of Jorg Siekmann's 60th birthday. In this game one player moves along the edges of a finite, directed or undirected...
Expressive Equivalence of Least and Inflationary Fixed-Point Logic (2002)
Stephan Kreutzer, Lufg Mathematische, Grundlagen Informatik, Rwth Aachen
We study the relationship between least and inflationary fixed-point logic. By results of Gurevich and Shelah from 1986, it has been known that on finite structures both logics have the same...
Generalising Automaticity to Modal Properties of Finite Structures (2002)
A. Dawar, Lufg Mathematische, Grundlagen Informatik, Rwth Aachen
We introduce a complexity measure of modal properties of finite structures which generalises the automaticity of languages. It is based on graph-automata like devices called labelling systems. We...
Inflationary Fixed Points in Modal Logic (2002)
Anuj Dawar, Stephan Kreutzer, Rwth Aachen
We consider an extension of modal logic with an operator for constructing...
Datalog LITE: A deductive query language with linear time model checking (2002)
Georg Gottlob, Erich Gr Adel, Rwth Aachen
this paper we investigate query languages that (1) encompass a natural recursion mechanism, (2) extend the expressive power of temporal logics such as CTL and the alternation-free -calculus, (3) have...
Thomas List and Jrg Kller (2002)
Thomas List, Jrg Kller, Informatik V Information Systems, Rwth Aachen
In electronic commerce trust building measures are one way to make a marketplace more attractive for suppliers and potential customers. Often trust on marketplaces is built up through external...
Workflow Support for Failure Management in Federated Organizations (2002)
Ralf Klamma, Peter Peters, Matthias Jarke, Informatik V (information Systems, Rwth Aachen
Failure management for complex products (such as production machinery) exemplifies a class of reactive workflow management tasks for which current WFMS offer few solutions. This class is...
Logics for Mazurkiewicz Traces (2002)
Martin Leucker, Aachener Informatik Berichte, Rwth Aachen, Technischen Hochschule, Aachen Erlangung
Linear temporal logic (LTL) has become a well established tool for specifying the dynamic behavior of reactive systems with an interleaving semantics and the automata-theoretic approach has proven to...
Martin Leucker, Aachener Informatik Berichte, Rwth Aachen, Technischen Hochschule, Aachen Erlangung
Linear temporal logic (LTL) has become a well established tool for specifying the dynamic behavior of reactive systems with an interleaving semantics and the automatatheoretic approach has proven to...
Fixed Point Formulae and Solitaire Games (2002)
Dietmar Berwanger, Mathematische Grundlagen Der Informatik, Rwth Aachen
The model checking games associated with fixed point logics are parity games, and it is currently not known whether the strategy problem for parity games can be solved in polynomial time. We study...
Workshop on Automata and Finite Model Theory (2002)
Organizers Lauri Hella, Juhani Karhumki, Kerkko Luosto, Dietmar Berwanger, Erich Gritdel, Mathematische Grundlagen Der Informatik, ...
James Rogers Department of Computer Science Earlham College Richmond, IN USA jrogers@cs.earlham.edu We extend the automata-theoretic characterizations of the weak monadic second-order definable sets...
Partial Fixed-Point Logic on Infinite Structures (2002)
Stephan Kreutzer, Lufg Mathematische, Grundlagen Informatik, Rwth Aachen
We consider an alternative semantics for partial fixed-point logic (PFP). To define the fixed point of a formula in this semantics, the sequence of stages induced by the formula is considered. As...
Expressive Equivalence of Least and Inflationary Fixed-Point Logic (2002)
Stephan Kreutzer, Lufg Mathematische, Grundlagen Informatik, Rwth Aachen
We study the relationship between least and inflationary fixed-point logic. By results of Gurevich and Shelah from 1986, it has been known that on finite structures both logics have the same...
Generalised Regular MSC Languages (2002)
Aachener Informatik Berichte, Rwth Aachen, Benedikt Bollig, Martin Leucker, Thomas Noll
In this paper, we establish the concept of regularity for languages consisting of Message Sequence Charts (MSCs). To this aim, we formalise their behaviour by string languages and give a natural...
An Open Framework for Data-Flow Analysis in Java (2002)
Markus Mohnen, Aachener Informatik Berichte, Rwth Aachen
We describe work in progress on a framework for data--flow based program analysis. By using this framework, researchers and developers can easily implement analyses, test their correctness, and...
Interfaces with Default Implementations in Java (2002)
Markus Mohnen, Aachener Informatik Berichte, Rwth Aachen
With the interface construct, Java features a concept with high potential for producing reusable code: Java's interfaces allow the definition of class properties independently of class inheritance....
Axiomatising Tree-Interpretable Structures (2002)
Generalising the notion of a prefix-recognisable graph to arbitrary relational structures we introduce the class of tree-interpretable structures. We prove that every tree-interpretable structure is...
Approximation and Difference in Description Logics (2002)
Sebastian Brandt, Rwth Aachen, Anni-yasmin Turhan
Approximation is a new inference service in Description Logics first mentioned by Baader, Küsters, and Molitor. Approximating a concept, defined in one Description Logic, means to translate this...
Ground Tree Rewriting Graphs of Bounded Tree Width (2002)
We analyze structural properties of ground tree rewriting graphs, generated by rewriting systems that perform replacements at the front of nite, ranked trees. The main result is that the class of...
OpenMesh - a generic and efficient polygon mesh data structure (2002)
M. Botsch, S. Steinberg, S. Bischoff, L. Kobbelt, Rwth Aachen
We describe the implementation of a half-edge data structure for the static representation and dynamic handling of arbitrary polygonal meshes. The particular design of the data structures and classes...
Combining Decision Procedures for Positive Theories Sharing Constructors (2002)
Franz Baader, Lehr- Forschungsgebiet, Theoretische Informatik, Rwth Aachen, Cesare Tinelli
This paper addresses the following combination problem: given two equational theories E 1 and E 2 whose positive theories are decidable, how can one obtain a decision procedure for the positive...
Approximation and Difference in Description Logics (2002)
Sebastian Br, T Ralf Kusters Anni-yasmin Turhan, Sebastian Brandt, Anni-yasmin Turhan, Lufg Theoretische Informatik, Rwth Aachen
Approximation is a new inference service in Description Logics first mentioned by Baader, Küsters, and Molitor. Approximating a concept, defined in one Description Logic, means to translate this...
OpenMesh -- a generic and efficient polygon mesh data structure (2002)
M. Botsch, S. Steinberg, S. Bischoff, L. Kobbelt, Rwth Aachen
We describe the implementation of a half-edge data structure for the static representation and dynamic handling of arbitrary polygonal meshes. The particular design of the data structures and classes...
Speech-To-Speech Translation Based On Finite-State Transducers (2001)
F. Casacuberta, D. Llorens, C. Martnez, S. Molau, F. Nevado, H. Ney, ...
Nowadays, the most successful speech recognition systems are based on stochastic finite-state networks (hidden Markov models and n-grams). Speech translation can be accomplished in a similar way as...
Adding Numbers to the Description Logic - First Results (2001)
Rwth Aachen, Lufg Theoretische Informatik, Carsten Lutz
Recently, the Description Logic (DL) SHIQ has found a large number of applications. This success is due to the fact that SHIQ combines a rich expressivity with ecient reasoning, as is demonstrated by...
Approximation and Difference in Description Logics (2001)
Sebastian Br, T Ralf Kusters Anni-yasmin Turhan, Sebastian Brandt, Anni-yasmin Turhan, Lufg Theoretische Informatik, Rwth Aachen
Approximation is a new inference service in Description Logics first mentioned by Baader, Küsters, and Molitor. Approximating a concept, defined in one Description Logic, means to translate this...
Optimised Reasoning for SHIQ (2001)
Rwth Aachen, Lufg Theoretische Informatik, Ian Horrocks, Ulrike Sattler
The tableau algorithm implemented in the FaCT knowledge representation system decides satis ability and subsumption in SHIQ, a very expressive description logic providing, e.g., inverse and...
Unification in a Description Logic with Transitive Closure of Roles (2001)
Lufg Theoretische Informatik, Franz Baader, Rwth Aachen
Unification of concept descriptions was introduced by Baader and Narendran as a tool for detecting redundancies in knowledge bases. It was shown that unification in the small description logic FL0 ,...
Operational Semantics for Fixed-Point Logics on Constraint Databases (2001)
In this paper we compare the expressive power of various xed-point logics on linear or dense order constraint databases. This comparison is not done on absolute terms, i.e. by comparing their...
Games and Model Checking for Guarded Logics (2001)
Dietmar Berwanger, Mathematische Grundlagen Der Informatik, Rwth Aachen
We investigate the model checking problems for guarded first-order and fixed point logics by reducing them to parity games. This approach is known to provide good results for the modal µ-calculus...
Functional programming languages for verification tools: experiences with ML and Haskell (2001)
Martin Leucker, Thomas Noll, Perdita Stevens, Michael Weber, Lehrstuhl Fur Informatik Ii, Rwth Aachen
We compare Haskell with ML as programming languages for verification tools, based on our experience developing TRUTH in Haskell and the Edinburgh Concurrency Workbench (CWB) in ML. We discuss not...
Functional programming languages for verification tools: experiences with ML and Haskell (2001)
Martin Leucker, Thomas Noll, Perdita Stevens, Michael Weber, Lehrstuhl Fur Informatik Ii, Rwth Aachen
We compare Haskell with ML as programming languages for verification tools, based on our experience developing TRUTH in Haskell and the Edinburgh Concurrency Workbench (CWB) in ML. We discuss not...
Deciding the Word Problem in the Union of Equational Theories (2001)
Franz Baader, Lehr- Forschungsgebiet, Theoretische Informatik, Rwth Aachen, Cesare Tinelli
this paper is a new method for combining
Prefix-Recognisable Graphs and Monadic Second-Order Logic (2001)
Aachener Informatik Berichte, Achim Blumensath, Lufg Mathematische, Grundlagen Informatik, Rwth Aachen
We present several characterisations of the class of prefix-recognisable
Cooperative Document Management (2001)
Mareike Schoop, Informatik V (information Systems, Rwth Aachen
this report). Cooperative document management is in itself an interesting area both for researchers and practitioners as it requires not only an efficient management of documents but also efficient...
Game Logic is Strong Enough for Parity Games (2001)
Dietmar Berwanger, Mathematische Grundlagen Der Informatik, Rwth Aachen
This paper is concerned with the expressive power of Parikh's Game Logic interpreted in Kripke structures. We show that the syntactical alternation hierarchy of this logic is strict, by expressing...
Refined Lexicon Models for Statistical Machine Translation using a Maximum Entropy Approach (2001)
Ismael Garc A Varea, Franz J. Och, Hermann Ney, Lehrstuhl Fur Inf Vi, Rwth Aachen, Francisco Casacuberta
Typically, the lexicon models used in statistical machine translation systems do not include any kind of linguistic or contextual information, which often leads to problems in performing a correct...
Modal Logic and the Two-Variable Fragment (2001)
Rwth Aachen, Lufg Theoretische Informatik, Carsten Lutz, Ulrike Sattler, Frank Wolter
. We introduce a modal language L which is obtained from standard modal logic by adding the dierence operator and modal operators interpreted by boolean combinations and the converse of accessibility...
Statistical Classification Methods for Arabic News Articles (2001)
Hassan Sawaf, Aixplain Ag, Rwth Aachen
In this paper, we present experimental results on document clustering and classification achieved on the Arabic NEWSWIRE corpus using statistical methods. Arabic is a highly inflecting language. The...
Automatic Extrapolation of Human Assessment of Translation Quality (2001)
Stephan Vogel, Hermann Ney, Lehrstuhl Fur Informatik Vi, Rwth Aachen
this paper could be set up to this end.
Finite Acceptance of Infinite Words (2001)
Igor Litovsky, F- Sophia, Antipolis Cedex, Ludwig Staiger, Rwth Aachen
In this paper we consider the following two types of finite acceptance of infinite words by finite automata: An infinite word is accepted if and only if there is a run on input for which an accepting...
The present paper links the concepts of Kolmogorov complexity (in Complexity theory) and Hausdorff dimension (in Fractal geometry) for a class of recursive (computable) !-languages.
Lazy Narrowing in a Graph Machine (2001)
Herbert Kuchen, Rita Loogen, Rwth Aachen
The paper investigates the implementation of lazy narrowing in the framework of a graph reduction machine. By extending an appropriate architecture for purely functional languages an abstract graph...
A Tableau Calculus for Temporal Description Logic: The Constant Domain Case. (2001)
Rwth Aachen, Lufg Theoretische Informatik, Carsten Lutz, Holger Sturm, Frank Wolter, Michael Zakharyaschev, ...
We show how to combine the standard tableau system for the basic description logic ALC and Wolper's tableau calculus for propositional temporal logic PTL (with the temporal operators `next-time' and...
Rwth Aachen, Lufg Theoretische Informatik, Carsten Lutz, Holger Sturm, Frank Wolter, Michael Zakharyaschev, ...
We show how to combine the standard tableau system for the basic description logic ALC and Wolper's tableau calculus for propositional temporal logic PTL (with the temporal operators `next-time' and...
GAP - Groups, Algorithms and Programming: version 3 release 4 patchlevel 4 (2001)
Hans Ulrich Besche, Thomas Breuer, Frank Celler, Bettina Eick, Volkmar Felsch, Alexander Hulpke, ...
Representations) implementing this idea. (A note on the name: We have chosen abstract" because we manipulate expressions for representations, not constants. However, concrete" would also be right...
First-Order Queries on Databases Embedded in an Infinite Structure (2001)
Martin Otto, Rwth Aachen, Jan Van Den Bussche
We consider "generic" (isomorphism-invariant) queries on relational databases embedded in an infinite background structure. Assume a generic query is expressible by a first-order formula over the...
On Model Checking Synchronised Hardware Circuits (2001)
Martin Leucker, Rwth Aachen, Lehrstuhl Fur Informatik Ii
. In this paper, we present a framework for specifying and verifying an important class of hardware systems. These systems are build up from a parallel composition of circuits switching by a global...
Guarded Fixed Point Logic (2001)
Erich Gradel, Rwth Aachen, Igor Walukiewicz
Guarded fixed point logics are obtained by adding least and greatest fixed points to the guarded fragments of firstorder logic that were recently introduced by Andr eka, van Benthem and N emeti....
Rwth Aachen, Lufg Theoretische Informatik, Carsten Lutz, Holger Sturm, Frank Wolter, Michael Zakharyaschev, ...
We show how to combine the standard tableau system for the basic description logic ALC with Wolper's tableau calculus for propositional temporal logic PTL in order to design a terminating sound and...
A Tableau Calculus for Temporal Description Logic: The Constant Domain Case (2001)
Rwth Aachen, Lufg Theoretische Informatik, Carsten Lutz, Holger Sturm, Frank Wolter, Michael Zakharyaschev
We show how to combine the standard tableau system for the basic description logic ALC with Wolper's tableau calculus for propositional temporal logic PTL in order to design a terminating sound and...
Georg Berks, Diedrich Graf V. Keyserlingk, Jan Jantzen, Mariagrazia Dotoli, Rwth Aachen
A clinical syndrome is a set or a cluster of concurrent symptoms which indicate together the presence and the nature of a disease. Looking for concurrent symptoms is therefore one of the main tasks...
A Tableau Calculus for Temporal Description Logic: The Constant Domain Case (2001)
Rwth Aachen, Lufg Theoretische Informatik, Carsten Lutz, Holger Sturm, Frank Wolter, Michael Zakharyaschev
We show how to combine the standard tableau system for the basic description logic ALC with Wolper's tableau calculus for propositional temporal logic PTL in order to design a terminating sound and...
One approach to integrating knowledge bases is based on finding assertions that relate the expressions in the constituent terminologies. For knowledge bases with many terms this task requires...
Achim Blumensath, Erich Grdel, Mathematische Grundlagen Der Informatik, Rwth Aachen
We study definability and complexity issues for automatic and w-automatic structures. These are, in general, infinite structures but they can be finitely presented by a collection of automata....
On the Restraining Power of Guards (2000)
Guarded fragments of first-order logic were recently introduced by Andr'eka, van Benthem and N'emeti; they consist of relational first-order formulae whose quantifiers are appropriately relativized...
Descriptive Complexity Theory over the Real Numbers (2000)
Erich Gradel, Klaus Meer, Rwth Aachen
We present a logical approach to complexity over the real numbers with respect to the model of Blum, Shub and Smale. The logics under consideration are interpreted over a special class of twosorted...
Guarded Fixed Point Logic (2000)
Erich Gradel, Rwth Aachen, Igor Walukiewicz
Guarded fixed point logics are obtained by adding least and greatest fixed points to the guarded fragments of firstorder logic that were recently introduced by Andr eka, van Benthem and N emeti....
Computing Least Common Subsumers in Description Logics with Existential Restrictions (2000)
Franz Baader, Ralf Kusters, Ralf Molitor, Lufg Theoretische Informatik, Rwth Aachen
Computing the least common subsumer (lcs) is an inference task that can be used to support the "bottom-up" construction of knowledge bases for KR systems based on description logics. Previous work on...
Structural Subsumption Considered from an Automata-Theoretic Point of View (2000)
F. Baader, R. Kusters, R. Molitor, Lufg Theoretische Informatik, Rwth Aachen
This paper compares two approaches for deriving subsumption algorithms for the description logic ALN : structural subsumption and an automata-theoretic characterization of subsumption. It turns out...