Multiprocessor Execution of Logic Programs


Book Description

Multiprocessor Execution of Logic Programs addresses the problem of efficient implementation of logic programming languages, specifically Prolog, on multiprocessor architectures. The approaches and implementations developed attempt to take full advantage of sequential implementation technology developed for Prolog (such as the WAM) while exploiting all forms of control parallelism present in logic programs, namely, or-parallelism, independent and-parallelism and dependent and-parallelism. Coverage includes a thorough survey of parallel implementation techniques and parallel systems developed for Prolog. Multiprocessor Execution of Logic Programs is recommended for people implementing parallel logic programming systems, parallel symbolic systems, parallel AI systems, and parallel theorem proving systems. It will also be useful to people who wish to learn about the implementation of parallel logic programming systems.




Parallel Execution of Logic Programs


Book Description

This book is an updated version of my Ph.D. dissertation, The AND/OR Process Model for Parallel Interpretation of Logic Programs. The three years since that paper was finished (or so I thought then) have seen quite a bit of work in the area of parallel execution models and programming languages for logic programs. A quick glance at the bibliography here shows roughly 50 papers on these topics, 40 of which were published after 1983. The main difference between the book and the dissertation is the updated survey of related work. One of the appendices in the dissertation was an overview of a Prolog implementation of an interpreter based on the AND/OR Process Model, a simulator I used to get some preliminary measurements of parallelism in logic programs. In the last three years I have been involved with three other implementations. One was written in C and is now being installed on a small multiprocessor at the University of Oregon. Most of the programming of this interpreter was done by Nitin More under my direction for his M.S. project. The other two, one written in Multilisp and the other in Modula-2, are more limited, intended to test ideas about implementing specific aspects of the model. Instead of an appendix describing one interpreter, this book has more detail about implementation included in Chapters 5 through 7, based on a combination of ideas from the four interpreters.




Parallel Execution of Logic Programs


Book Description

Logic programming refers to execution of programs written in Horn logic. Among the advantages of this style of programming are its simple declarativeand procedural semantics, high expressive power and inherent nondeterminism. The papers included in this volume were presented at the Workshop on Parallel Logic Programming held in Paris on June 24, 1991, as part of the 8th International Conference on Logic Programming. The papers represent the state of the art in parallel logic programming, and report the current research in this area, including many new results. The three essential issues in parallel execution of logic programs which the papers address are: - Which form(s) of parallelism (or-parallelism, and-parallelism, stream parallelism, data-parallelism, etc.) will be exploited? - Will parallelism be explicitly programmed by programmers, or will it be exploited implicitly without their help? - Which target parallel architecture will the logic program(s) run on?




Parallel Computing on Distributed Memory Multiprocessors


Book Description

Advances in microelectronic technology have made massively parallel computing a reality and triggered an outburst of research activity in parallel processing architectures and algorithms. Distributed memory multiprocessors - parallel computers that consist of microprocessors connected in a regular topology - are increasingly being used to solve large problems in many application areas. In order to use these computers for a specific application, existing algorithms need to be restructured for the architecture and new algorithms developed. The performance of a computation on a distributed memory multiprocessor is affected by the node and communication architecture, the interconnection network topology, the I/O subsystem, and the parallel algorithm and communication protocols. Each of these parametersis a complex problem, and solutions require an understanding of the interactions among them. This book is based on the papers presented at the NATO Advanced Study Institute held at Bilkent University, Turkey, in July 1991. The book is organized in five parts: Parallel computing structures and communication, Parallel numerical algorithms, Parallel programming, Fault tolerance, and Applications and algorithms.




Scalable Shared Memory Multiprocessors


Book Description

Mathematics of Computing -- Parallelism.




Parallel Execution of Parlog


Book Description

This monograph concentrates on the implementation of concurrent logic programming languages on loosely-coupled parallel computer architectures. Two different abstract models are also considered: a graph reduction based model and a more imperative approach. The design of a specialized instruction set is presented that is general enough to be used for the whole family of concurrent logic programming languages. In particular the language Parlog is concentrated upon because it is the most efficiently implementable of all the non-flat logic programming languages. Other issues arising from the implementation of a programming language are discussed, in particular the design of a load balancing scheme which deals with the large number of short-lived processes inherent in a correct language implementation. Detailed descriptions of all the data structures and synchronisation algorithms are also presented. Resource exhaustion is also discussed and handled within the implementations. Detailed performance results for both models of computation are given. From the material it should be possible for the reader to create an implementation.




Parallel and Constraint Logic Programming


Book Description

Constraint Logic Programming (CLP), an area of extreme research interest in recent years, extends the semantics of Prolog in such a way that the combinatorial explosion, a characteristic of most problems in the field of Artificial Intelligence, can be tackled efficiently. By employing solvers dedicated to each domain instead of the unification algorithm, CLP drastically reduces the search space of the problem, which leads to increased efficiency in the execution of logic programs. CLP offers the possibility of solving complex combinatorial problems in an efficient way, and at the same time maintains the advantages offered by the declarativeness of logic programming. The aim of this book is to present parallel and constraint logic programming, offering a basic understanding of the two fields to the reader new to the area. The first part of the book gives an introduction to the fundamental aspects of conventional logic programming which is necessary for understanding the parts that follow. The second part includes an introduction to parallel logic programming, architectures and implementations proposed in the area. Finally, the third part presents the principles of constraint logic programming. The last two parts also include descriptions of the supporting facilities for the two paradigms in two popular systems; ECLIPSe and SICStus. These platforms have been selected mainly because they offer both parallel and constraint features. Annotated and explained examples are also included in the relevant parts, offering a valuable guide and a first practical experience to the reader. Finally, applications of the covered paradigms are presented. The authors felt that a book of this kind should provide some theoretical background necessary for the understanding of the covered logic programming paradigms, and a quick start for the reader interested in writing parallel and constraint logic programming programs. However it is outside the scope of this book to provide a deep theoretical background of the two areas. In that sense, this book is addressed to a public interested in obtaining a knowledge of the domain, without spending the time and effort to understand the extensive theoretical work done in the field – namely postgraduate and advanced undergraduate students in the area of logic programming. This book fills a gap in the current bibliography, since there is no comprehensive book of this level that covers the areas of conventional, parallel, and constraint logic programming. Parallel and Constraint Logic Programming: An Introduction to Logic, Parallelism and Constraints is appropriate for an advanced level course on Logic Programming or Constraints, and as a reference for practitioners and researchers in industry.




Programming Language Implementation and Logic Programming


Book Description

This volume contains the papers which have been accepted for presentation atthe Third International Symposium on Programming Language Implementation andLogic Programming (PLILP '91) held in Passau, Germany, August 26-28, 1991. The aim of the symposium was to explore new declarative concepts, methods and techniques relevant for the implementation of all kinds of programming languages, whether algorithmic or declarative ones. The intention was to gather researchers from the fields of algorithmic programming languages as well as logic, functional and object-oriented programming. This volume contains the two invited talks given at the symposium by H. Ait-Kaci and D.B. MacQueen, 32 selected papers, and abstracts of several system demonstrations. The proceedings of PLILP '88 and PLILP '90 are available as Lecture Notes in Computer Science Volumes 348 and 456.







Programming Constraint Services


Book Description

Constraint Programming is an approach for modeling and solving combi- torial problems that has proven successful in many applications. It builds on techniques developed in Arti?cial Intelligence, Logic Programming, and - erations Research. Key techniques are constraint propagation and heuristic search. Constraint Programming is based on an abstraction that decomposes a problem solver into a reusable constraint engine and a declarative program modeling the problem. The constraint engine implements the required pr- agation and search algorithms. It can be realized as a library for a general purpose programming language (e.g. C++), as an extension of an existing language (e.g. Prolog), or as a system with its own dedicated language. The present book is concerned with the architecture and implementation of constraint engines. It presents a new, concurrent architecture that is far superior to the sequential architecture underlying Prolog. The new archit- ture is based on concurrent search with copying and recomputation rather than sequential search with trailing and backtracking. One advantage of the concurrent approach is that it accommodates any search strategy. Furth- more, it considerably simpli?es the implementation of constraint propagation algorithms since it eliminates the need to account for trailing and backtra- ing. The book investigates an expressive generalization of the concurrent - chitecture that accommodates propagation-preserving combinators (known as deep guard combinators) for negation, disjunction, implication, and re- cation of constraint propagators. Such combinators are beyond the scope of Prolog’s technology. In the concurrent approach they can be obtained with a re?ective encapsulation primitive.