Advanced Concurrent Constraint Languages: Application, Implementation and Methodology

Description

Project Title:: Advanced Concurrent Constraint Languages: Application, Implementation and Methodology
Acronym:: ACCLAIM
Number:: 7195
Work Area:: Logics & Logic Programming
Coordinator:: Swedish Institute of Computer Science
Logic Programming Systems Laboratory
Isafjordsgatan 26
Box 1263
S - 164 28 Kista
Coordinator Country:: S
Partners: Research Institute for Symbolic Computation A
Katholieke Universiteit Leuven B
Deutsches Forschungszentrum für Künstliche Intelligenz D
Universidad Politécnica de Madrid E
DEC Paris Research Laboratory F
INRIA-Roquencourt F
Université d'Aix-Marseille II F
Università di Pisa I
Contact Point:: Prof. S. Haridi
Telephone:: +46/8 752 1572
Fax:: +46/8 751 7230
E-Mail:: haridi@sics.se
Keywords:: concurrent constraint programming, symbolic computation, constraints, concurrency, parallelism
Start Date:: 1 September 92
Duration:: 36 months
Status:: running
Abstract:: This project aims to further the conceptual, mathematical and practical foundations of concurrent constraint programming, and in so doing, provide a framework for designing and implementing advanced computational tools for the development of complex, symbolic computational tasks in areas such as knowledge-representation and reasoning, design, diagnosis, simulation, scheduling, and natural language understanding.

AIMS

ACCLAIM aims to:
- extend the foundations of concurrent constraint programming to account for a richer class of conputational phenomena
- develop efficient constraint techniques to tackle new application areas and to produce extensible general-purpose constraint systems
- develop frameworks and techniques for compile-time analysis and optimisation of concurrent constraint programs
- improve the implementation technology of concurrent constraint languages to be competitive with imperative languages, and to achieve a high degree of parallel execution on multi-processor architectures.

APPROACH AND METHODS

ACCLAIM brings together an interdisciplinary team of the leading European researchers in this area. In addition, fruitful cooperation with leading US researchers is expected.

PROGRESS AND RESULTS

For the first year, seventeen public deliverable reports have been produced, which are available on request from the coordinator. Most correspond to articles published in international journals and conferences.
Novel language designs have been investigated that better support the needs of applications based on constraints: AKL, Oz, LIFE, clp(FD), and CLP(PB). For these, sequential and parallel prototype implementations are being developed.
Several problem-oriented constraint systems have been defined: finite domain constraints (FD), feature tree constraints (FT), order-sorted feature constraints (OSF), piece-wise linear constraints, list constraints, interval constraints, and pseudo-boolean constraints (PB). For these, efficient constraint solving algorithms are being designed, analysed, and implemented.
Compile-time program analysis frameworks based on abstract interpretation have been proposed. These will benefit both parallel and sequential implementations by providing safe approximations of the runtime behaviour of programs.
The formal properties of programs have been analysed. For this purpose an algebraic semantics for a concurrent abstract machine (CHARM) has been developed, and a true-concurrency semantics for both indeterministic and nondeterministic programs has been provided.

POTENTIAL

The consortium expects to generate the technological base that will allow the development and deployment of path-breaking, semantically based, performance-efficient parallel systems for symbolic computation.

LATEST PUBLICATIONS

Janson S, Montelius J, and Haridi S Ports for Objects in Concurrent Logic Programs In: Research Directions in Concurrent Object-Oriented Programming, MIT Press (1993)
Äit-Kaci H, Podelski A and Goldstein S C Order-Sorted Feature Theory Unification In: Logic Programming: Proceedings of the 1993 International Symposium, MIT Press (1993)
Henz M, Smolka G and Würtz J Oz - A Programming Language for Multi-Agent Systems In: Proceedings of the 13th International Joint Conference on Artificial Intelligence, Morgan Kaufmann (1993)
Diaz D and Codognet P A Minimal Extension of the WAM for clp(FD) In: Logic Programming: Proceedings of the Tenth International Conference, MIT Press (1993)
Moolenaar R and Demoen B A Parallel Implementation of AKL Programming Language Implementation and Logic Programming, LNCS, Springer-Verlag (1993)
Garcia de la Banda M, Hermenegildo M and Marriott K Independence in Constraint Logic Programs In: Logic Programming: Proceedings of the 1993 International Symposiumm, MIT Press (1993)
Corradini A, Montanari U and Rossi F A Concurrent Abstract Machine for Distributed Systems: CHARM Journal of Theoretical Computer Science, to appear
Benhamou F and Massat J L Boolean Pseudo-equations in CLP In: Logic Programming: Proceedings of the Tenth International Conference, MIT Press (1993)

INFORMATION DISSEMINATION ACTIVITIES

Project results have been published and presented in international journals and conferences. ACCLAIM organised a workshop on Concurrent Constraint Programming at ICLP'93 in Budapest (June 25, 1993). Partners of ACCLAIM are participating in the organisation of the conference Constraints in Computational Logics (September 6-8, 1994).

Sven Müßig, last update 07-nov-1995. Your feedback is welcome.