The development of database technology has currently reached the stage of deductive database systems which use Horn clauses for defining relations. An important characteristic of these systems is the clear separation of logic and control. However, the programmer cannot affect the control part of a deductive database system. To eliminate this deficiency, this monograph presents a so-called expert deductive database system that allows explicit control of the deduction process. The system consists of an object-level describing the logical aspects of a problem and of a meta-level that contains application-specific control information affecting the object-level deduction process. For example, object-level rules can be disregarded, and some tuples deduced at the object-level can be preferred to others. Besides the architecture of this system, the book also identifies some important possibilities of deduction control which are explained by characteristic examples.

This book constitutes the refereed post-conference proceedings of the Second International Andrei Ershov Memorial Conference on System Informatics, held in Akademgorodok, Novosibirsk, Russia, in June 1996. The 27 revised full papers presented together with 9 invited contributions were thoroughly refereed for inclusion in this volume. The book is divided in topical sections on programming methodology, artificial intelligence, natural language processing, machine learning, dataflow and concurrency models, parallel programming, supercompilation, partial evaluation, object-oriented programming, semantics and abstract interpretation, programming and graphical interfaces, and logic programming.

Computer Systems and Software Engineering is a compilation of sixteen state-of-the-art lectures and keynote speeches given at the COMPEURO '92 conference. The contributions are from leading researchers, each of whom gives a new insight into subjects ranging from hardware design through parallelism to computer applications. The pragmatic flavour of the contributions makes the book a valuable asset for both researchers and designers alike. The book covers the following subjects: Hardware Design: memory technology, logic design, algorithms and architecture; Parallel Processing: programming, cellular neural networks and load balancing; Software Engineering: machine learning, logic programming and program correctness; Visualization: the graphical computer interface.

Reviews of Environmental Contamination and Toxicology publishes authoritative reviews on the occurrence, effects, and fate of pesticide residues and other environmental contaminants. It will keep you informed of the latest significant issues by providing in-depth information in the areas of analytical chemistry, agricultural microbiology, biochemistry, human and veterinary medicine, toxicology, and food technology.

The proceedings of the fourth Vienna Development Method Symposium, VDM '91, are published here in two volumes. Previous VDM symposia were held in 1987 (LNCS 252), 1988 (LNCS 328), and 1990 (LNCS 428). The VDM symposia have been organized by the VDM Europe, formed in 1985 as an advisory board sponsored by the Commission of the European Communities. The VDM Europe working group consisted of reasearchers, software engineers, and programmers, all interested in prommoting the industrial usage of formal methods for software development. The fourth VDM symposium presented not only VDM but also a large number of other methods for formal software development. Volume 1 contains the conference contributions. It has four parts: contributions of invited speakers, papers, project reports, and tools demonstration abstracts. The emphasis is on methods and calculi for development, verification and verification tools support, experiences from doing developments, and the associated theoretical problems. Volume2 contains four introductory tutorials (on LARCH, Refinement Calculus, VDM, and RAISE) and four advanced tutorials (on ABEL, PROSPECTRA, THE B Method, and The Stack). They present a comprehensive account of the state of theart.

Active database systems enhance traditional database functionality with powerful rule-processing capabilities, providing a uniform and efficient mechanism for many database system applications. Among these applications are integrity constraints, views, authorization, statistics gathering, monitoring and alerting, knowledge-based systems, expert systems, and workflow management. This significant collection focuses on the most prominent research projects in active database systems. The project leaders for each prototype system provide detailed discussions of their projects and the relevance of their results to the future of active database systems. Features: A broad overview of current active database systems and how they can be extended and improved A comprehensive introduction to the core topics of the field, including its motivation and history Coverage of active database (trigger) capabilities in commercial products Discussion of forthcoming standards

The systematic development of software systems is a central task of computing science. A software system is the result of putting together knowledge about the application, the requirements and the structures of computing science. Under the heading CIP (Computer-aided Intuition-guided Programming), a group of researchers led by Prof. F.L. Bauer and Prof. K. Samelson started work in 1975 in the direction of formal program specification, transformational programming, and tool supportfor program development. The collection of papers in this volume presents examples of a formal approach to programming language concepts and program development based on algebraic specifications and program transformations. Examples are also presented of evolutions and modificationsof the original ideas of the CIP project. The topics range from descriptionsof the program development process to derivations of algorithms from specifications. The volume is dedicated to Prof. F.L. Bauer.