The third European Software Engineering Conference follows ESEC'87 and ESEC'89. This series of conferences was set up by the European societies with the aim of providing an international forum for researchers, developersand users of software engineering technology. The need for a meeting point to discuss new results and useful experiences was clear from the large amount of high-quality European software engineering researchin recent years, stimulated, for example, through major European research programmes. The 22 papers in these proceedings were selected from 133 papers submitted from 26 different countries. They cover a fairly broad range of themes such as formal methods and practical experiences with them, special techniques for real-time systems, software evolution and re-engineering, software engineering environments, and software metrics. Invited papers by well-known experts address further important areas: perspectives on configuration management, software factories, user interfacedesign, computer security, and technology transfer.

The Portuguese Association for Artificial Intelligence has been organizing Portuguese Conferences on Artificial Intelligence, now held every second year, since 1985. This volume contains selected papers from the Fifth Conference on Artificial Intelligence. The conference has an international status: 62 contributions from 13 countries were received, of which 26 were from Portugal. To guarantee a high scientific standard, all the contributions were reviewed by at least three researchers,and only 20 papers were accepted and included in these proceedings. The papers are organized into sections on constraints, search, knowledge representation, temporal reasoning, planning, diagnosis and repair, and learning.

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.

The Z notation has been developed at the Programming Research Group at the Oxford University Computing Laboratory and elsewhere for over a decade. It is now used by industry as part of the software (and hardware) development process in both Europe and the USA. It is currently undergoing BSI standardisation in the UK, and has been proposed for ISO standardisation internationally. In recent years researchers have begun to focus increasingly on the development of techniques and tools to encourage the wider application of Z and other formal methods and notations. This volume contains papers from the Seventh Annual Z User Meeting, held in London in December 1992. In contrast to previous years the meeting concentrated specifically on industrial applications of Z, and a high proportion of the participants came from an industrial background. The theme is well represented by the four invited papers. Three of these discuss ways in which formal methods are being introduced, and the fourth presents an international survey of industrial applications. It also provides a reminder of the improvements which are needed to make these methods an accepted part of software development. In addition the volume contains several submitted papers on the industrial use of Z, two of which discuss the key area of safety-critical applications. There are also a number of papers related to the recently-completed ZIP project. The papers cover all the main areas of the project including methods, tools, and the development of a Z Standard, the first publicly-available version of which was made available at the meeting. Finally the volume contains a select Z bibliography, and section on how to access information on Z through comp.specification.z, the international, computer-based USENET newsgroup. Z User Workshop, London 1992 provides an important overview of current research into industrial applications of Z, and will provide invaluable reading for researchers, postgraduate students and also potential industrial users of Z.

CONCUR'91 is the second international conference on concurrency theory, organized in association with the NFI project Transfer. It is a sequel to the CONCUR'90 conference. Its basic aim is to communicate ongoing work in concurrency theory. This proceedings volume contains 30 papers selected for presentation at the conference (from 71 submitted) together with four invited papers and abstracts of the other invited papers. The papers are organized into sections on process algebras, logics and model checking, applications and specification languages, models and net theory, design and real-time, tools and probabilities, and programming languages. The proceedings of CONCUR'90 are available asVolume 458 of Lecture Notes in Computer Science.

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?