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Advanced Concurrent Constraint Languages: Application, Implementation and Methodology

Objective

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.
Research on concurrent constraint programming, will help to 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.

So far 17 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: ALK, 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.
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.

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

Coordinator

SWEDISH INST. OF COMPUTER SCIENCE
Address
Isafjordsgatan, 22, 1263
16428 Kista
Sweden

Participants (8)

Deutsches Forschungszentrum für Künstliche Intelligenz GmbH
Germany
Address
Erwin-schrödinger-straße
67663 Kaiserslautern
Institut National de Recherches en Informatique et en Automatique (INRIA)
France
Address
Domaine De Voluceau Rocquencourt
78153 Le Chesnay
J. KEPLER LINZ UNIVERSITAET
Austria
Address
C/o Johannes Kepler University
4040 Linz
KATHOLIEKE UNIVERSITEIT LEUVEN
Belgium
Address
Tervuursevest, 101
3000 Leuven
PARIS RESEARCH LABORATORY DIGITAL EQUIPMENT
France
Address
85 Avenue Victor Hugo
92563 Rueil-malmaison
UNIVERSITAT POLITECNICA DE MADRID
Spain
Address
Campus De Montegancedo
28660 Madrid
UNIVERSITE D'AIX-MARSEILLE II
France
Address
27 Boulevard Jean-moulin
13005 Marseille
Università degli Studi di Pisa
Italy
Address
Lungarno Pacinotti 45
56100 Pisa