Abstract: "We describe the current state of development of the concurrent constraint language GDCC (Guarded Definite Clauses with Constraints), is a member of the cc (Concurrent Constraint) family of languages which supports multiple solvers and recursive queries in a committed-choice framework...

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Bibliographic Details

Main Author:	Hawley, David (Author)
Format:	Book
Language:	English
Published:	Tokyo, Japan 1991
Series:	Shin-Sedai-Konpyūta-Gijutsu-Kaihatsu-Kikō <Tōkyō>: ICOT technical report 713
Subjects:	Concurrent programming
Summary:	Abstract: "We describe the current state of development of the concurrent constraint language GDCC (Guarded Definite Clauses with Constraints), is a member of the cc (Concurrent Constraint) family of languages which supports multiple solvers and recursive queries in a committed-choice framework. GDCC models computation as the interaction of multiple cooperating agents through the exchange of information via querying and asserting the information into a central repository. Concretely, this paradigm is embedded in a guarded (conditional) reduction system, where the guards contain the queries and assertions Control is achieved by requiring that the queries in a guard are true (entailed), and that the assertions are consistent (satisfiable), with respect to the current state of the repository. GDCC is an experimental cc language, which supports a user-specified set of sorts and constraint symbols in a committed-choice framework, and is intended to be a research tool for investigating issues of constraint-solving in concurrent programming languages, such as problem decomposition, use of multiple solvers and hybrid techniques, ordering of constraints, management of semi- decidable solution methods, debugging techniques, etc We introduce the language, its implementation in KL1[NaI89a], and a parallel constraint solver for rational polynomials based on a parallel implementation of the Buchberger Algorithm. The Buchberger Algorithm is a basic technology for symbolic algebra, and several attempts at its parallelization have appeared in the recent literature, with some good results for shared memory machines. The algorithm we present is designed for the distributed-memory Multi-PSI, but nevertheless shows consistently good performance and speedups for a number of standard benchmarks from the literature.
Physical Description:	17 S.