Chandrabose Aravindan and Dorothea Schaefer

In this report, we introduce the internet virtual library of logic programming systems and test cases, that we maintain here at the University of Koblenz, Germany since July, 1996. The library can be accessed on the world wide web at the URL:

http://www.uni-koblenz.de/ag-ki/LP/.

The main aim of this library is to provide a collection of Logic Programming Systems that focus on non-monotonic aspects such as abduction, non-monotonic negation, classical or extended negation, different forms of disjunction etc. The past decade has seen a lot of research activities in logic programming and non-monotonic reasoning that has resulted in various semantics for negation and disjunction in logic programming. Realizing the importance of efficient implementation of these semantics, so that they can be applied in solving real-world problems, many researchers are now concentrating on developing systems and applications. This library aims to bring all such efforts together by collecting and disseminating information on them.

The idea for maintaining such a library was conceived during a seminar on "Disjunctive Logic Programming and Databases: Non-Monotonic Aspects" organized by J. Dix, D. W. Loveland, J. Minker, and D. S. Warren at Dagstuhl, Germany during July 1-5, 1996 [DLMW96,Sei96] (see the seminar home page at the URL <http://www.uni-koblenz.de/ag-ki/dag9627/> for more information). During this seminar, T. Przymusinski organized a special session on project descriptions and system implementations that included system demonstrations. Various logic programming systems that focus on non-monotonic aspects were demonstrated by L. M. Pereira & his colleagues, I. Niemelae, P. Baumgartner, D. Seipel, F. Bry & A. H. Yahya, S. Brass, and D. S. Warren & his colleagues. Following these successful demonstrations, that aroused a lot of interesting discussions, it was decided to maintain a web page that provides information on these and other such systems. The artificial intelligence research group at the University of Koblenz volunteered to do that job and subsequently this library was born.

Currently, the library consists of information on nine systems. A brief description of these systems is given below. Please visit the library on the web for more information and links.

- ALP-MGTP

Description: Abductive logic programming system based on bottom-up, incremental, backtrack-free computation of the minimal models for disjunctive programs using a model generation theorem prover.

Developer: Katsumi Inoue

Contact: inoue@tutics.tut.ac.jp

Availability: free

URL: http://www.icot.or.jp/AITEC/PUBLICATIONS/Itaku/95/ catalogue8-E.htm

Requirements: Prolog on UNIX Workstation. The software is tested for running in SICStus Prolog v.2.1#9 on SunOS 4.1.3.

- DISPUTE

Description: Prototypical realization of disputation-based semantics

Developer: Michael Thielscher

Contact: mit@intellektik.informatik. th-darmstadt.de

Availability: free

Requirements: Quintus Prolog

- dlv

Description: Deductive system for non-monotonic reasoning

Developers: Nicola Leone, Cristinel Mateis, Gerald Pfeifer

Contact: pfeifer@dbai.tuwien.ac.at

Availability: free

URL: http://www.dbai.tuwien.ac.at/proj/dlv/

Requirements: Any system with an ANSI C++ compliant compiler. The graphical user interface requires Tcl/Tk.

- PROTEIN

Description: Theorem prover with a theory extension interface which serves as an interpreter for positive disjunctive logic programs. Additionally it can can reason with respect to generalized closed world assumption based on negation by failure to explain.

Developers: Artificial Intelligence Research Group at the University of Koblenz

Contact: ki-inf@informatik. uni-koblenz.de

Availability: free. World Wide Web interface to run the system is available at the following URL.

URL: http://www.uni-koblenz.de/ag-ki/Systems/Protein/

Requirements: EcLiPSe Prolog

- REVISE

Description: Extended LP system for revising knowledge bases

Developer: Carlos Viegas Damasio

Contact: cd@di.fct.unl.pt

Availability: free and system interface

URL: http://www.kbs.uni-hannover.de/~schroede/revise/revise.html

Requirements: SICStus Prolog 2.1

- smodels

Description: Implementation of the stable model semantics

Developers: Ilkka Niemelae and Patrik Simons

Contact: Ilkka.Niemela@hut.fi

Availability: free

URL: http://saturn.hut.fi/pub/smodels/

Requirements: C++ compiler

-

STATIC

Description: Prototype implementation of the static semantics

Developer: Stefan Brass

Contact: sb@informatik.uni-hannover.de

Availability: free

URL: http://www-db.informatik.uni-hannover.de/ftp/software/static/

Requirements: more or less any Prolog system

- XRay

Description: Implementation platform for query-answering in default logics Developers: S. Bruening, P. Nicolas, T. Schaub

Contact: torsten@uni-potsdam.de

Availability: free

Requirements: Standard Prolog, preferably Eclipse

- XSB

Description: Full Prolog system with tabling for well-founded semantics

Developers: David S. Warren, Terrance Swift, Konstantinos Sagonas, Prasad Rao, Juliana Freire

Contact: xsb-contact@cs.sunysb.edu

Availability: free

URL: http://www.cs.sunysb.edu/~sbprolog/xsb-page.html

Requirements: any 32-bit Unix machine we know of or DOS/ Windows /windows 95. For installation under Unix a C compiler is required.

This library is by no means complete and we need your help in obtaining information on systems that are not listed here. If you are currently developing a system that can handle (disjunctive) logic programs with negation please visit our library and fill in the system form. Please feel free to contact us, should you have any comments, suggestions on this effort.

Universitaet Koblenz-Landau,

Fachbereich Informatik

Rheinau 1, D-56075 Koblenz,

Germany.

{arvind,doro}@informatik.uni-koblenz.de