The papers in this volume were presented at the First International Workshop on Larch, held at MIT Endicott House near Boston on 13-15 July 1992. Larch is a family of formal specification languages and tools, and this workshop was a forum for those who have designed the Larch languages, built tool support for them, particularly the Larch Prover, and used them to specify and reason about software and hardware systems. The Larch Project started in 1980, led by John Guttag at MIT and James Horning, then at Xerox/Palo Alto Research Center and now at Digital Equipment Corporation/Systems Research Center (DEC/SRC). Major applications have included VLSI circuit synthesis, medical device communications, compiler development and concurrent systems based on Lamport's TLA, as well as several applications to classical theorem proving and algebraic specification. Larch supports a two-tiered approach to specifying software and hardware modules. One tier of a specification is wrillen in the Larch Shared Language (LSL). An LSL specification describes mathematical abstractions such as sets, relations, and algebras; its semantics is defined in terms of first-order theories. The second tier is written in a Larch interface language, one designed for a specific programming language. An interface specification describes the effects of individual modules, e.g. state changes, resource allocation, and exceptions; its semantics is defined in terms of first-order predicates over two states, where state is defined in terms of the programming language's notion of state. Thus, LSL is programming language independent; a Larch interface language is programming language dependent.

The areas of active and real-time databases have seen a tremendous growth of interest in the past few years, particularly with regard to their support of time-critical and embedded applications. ARTDB-95 provided, therefore, an important forum for researchers from both communities to discuss research results, and also to chart new directions for the future. As well as the 11 submitted papers presented at the workshop, this volume also contains 4 invited papers on the following topics: the impact of active databases on commercial practice; the optimization of active database transactions; the need for better language, compiler and tool support for real-time databases; and the origin of time constraints associated with data, events and actions. Together the papers give a comprehensive overview of current research, and will provide invaluable reading for academic and industrial researchers and students at both undergraduate and postgraduate level.

This book is the proceedings of the Structures in Concurrency Theory workshop (STRICT) that was held from 11 th to l3th May 1995 in Berlin, Germany. It includes three invited contributions - by J. de Bakker, E. Best et aI, and E. R. Olderog and M. Schenke - and all papers which were submitted and accepted for presentation. Concurrency Theory deals with formal aspects of concurrent systems. It uses partly competing and partly complementary formalisms and structures. The aim of this workshop was to present and compare different formalisms and results in Concurrency Theory. STRICT was organized by the Humboldt-University Berlin and the ESPRIT Basic Research Working Group CALIBAN. Original papers had been sought from all scientists in the field of Concurrency Theory. The Programme Committee selected twenty contributions with various different topics, including Petri Nets, Process Algebras, Distributed Algorithms, Formal Semantics, and others. I am grateful to the Programme Committee and to the other referees for the careful evaluation of the submitted papers.

This volume results from the four-day scientific Second International East/West Database Workshop which took place 25th-28th September 1994, in Klagenfurt, Austria, continuing a series of workshops started in Kiev in 1990 (Lecture Notes in Computer Science No. 504, Springer, "Next Generation Information System Technology"). The aims of this workshop are twofold: first, to provide a forum for the presentation and in-depth discussion of scientific achievements in the field of advanced databases that will effectively improve the building and use of future information systems; second, to establish and increase communication between research communities which were formerly separated and, therefore, had only rare opportunities to interact. It should establish contacts between researchers from the East and from the West to make exchange of ideas possible and to trigger collaborations. However, it is not only political borders which change their perviousness as a result of -or giving rise to -new autonomies or new possibilities for interaction and collaboration. The same happens with the borders between scientific areas, in particular in the dynamically evolving areas of computer science. Databases and programming languages are integrated in object oriented databases, database and information retrieval technology form together the basis for modern (multimedia) information systems. Furthermore, the borders between different information systems change and allow various forms of collaboration while maintaining different degrees of autonomy. Heterogeneous and distributed databases are enabling technologies for these systems.

SoSL was the first International Workshop on Semantics of Specification Languages, held from 25-27 October 1993 in Utrecht, the Netherlands. The workshop was organized by the Department of Philosophy of Utrecht University with financial support from the Nationale Faciliteit Informatica of the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), and under the auspices of the British Computer Society'S specialist group in Formal Aspects of Computing Science (BCS FACS). The concern of the workshop was the semantics of specification languages, and the issues closely related to this area, such as type checking and the justification of proof rules and proof obligations. Its aim was the exchange of problems and ideas in this field of formal methods, and the identification of common programs of work for further investigation. The program of SoSL consisted of 3 invited lectures presenting the developments of the semantics of 3 major specification languages. Furthermore, there were 16 presentations of submitted papers. This volume provides a direct account of the workshop. It contains 3 papers that match the invited lectures and the 16 selected papers. The editors want to thank all those who have contributed to the workshop; the Program Committee and the referees for selecting the contributed papers, the invited speakers for their interesting talks, the Organizing Committee for all their efforts, and of course the participants. We have the feeling that the workshop was worthwhile and should be repeated.

This book is the proceedings of a workshop held at Heriot-Watt University in Edinburgh in August 1993. The central theme of the workshop was rules in database systems, and the papers presented covered a range of different aspects of database rule systems. These aspects are reflected in the sessions of the workshop, which are the same as the sections in this proceedings: Active Databases Architectures Incorporating Temporal Rules Rules and Transactions Analysis and Debugging of Active Rules Integrating Graphs/Objects with Deduction Integrating Deductive and Active Rules Integrity Constraints Deductive Databases The incorporation of rules into database systems is an important area of research, as it is a major component in the integration of behavioural information with the structural data with which commercial databases have traditionally been associated. This integration of the behavioural aspects of an application with the data to which it applies in database systems leads to more straightforward application development and more efficient processing of data. Many novel applications seem to need database systems in which structural and behavioural information are fully integrated. Rules are only one means of expressing behavioural information, but it is clear that different types of rule can be used to capture directly different properties of an application which are cumbersome to support using conventional database architectures. In recent years there has been a surge of research activity focusing upon active database systems, and this volume opens with a collection of papers devoted specifically to this topic.

This volume contains papers from the OOPSLA-93 Conference Workshop on Security for Object-Oriented Systems, held in Washington DC, USA, on 26 September 1993. The workshop addressed the issue of how to introduce an acceptable level of security into object-oriented systems, as the use of such systems becomes increasingly widespread. The topic is approached from two different, but complementary, viewpoints: the incorporation of security into object-oriented systems, and the use of object-oriented design and modelling techniques for designing secure applications. The papers cover a variety of issues, relating to both mandatory and discretionary security, including security facilities of PCTE, information flow control, the design of multilevel secure data models, and secure database interoperation via role translation. The resulting volume provides a comprehensive overview of current work in this important area of research.

The International Workshop on Temporal Databases held in Zurich, Switzerland, 17-18 September 1995 brought together researchers from academic and industrial institutions with database practitioners interested in keeping up with the state-of-the-art developments in the management of temporal data. A previous workshop in Arlington, Texas in June 1993 focused on the development of an infrastructure that would spur the development of commercial implementations of many of the generally agreed-upon features of temporal database management that have emerged from the temporal database research community over more than a decade of research. This ARP AlNSF-sponsored Arlington workshop saw the formation of the TSQL2 Language Design Committee, which led to the development of the recently completed TSQL2 Language Specification, and also created a "consensus" glossary of temporal database terminology and a test suite of temporal database queries. The Zurich workshop was conceived from the outset to be universal in scope, and international in participation. The Call for Papers sought to evoke the highest quality and most up-to-date temporal database research from around the world. Mindful of the important work accomplished by the previous workshop, the Call also specifically sought out research papers and panels that would comment and build upon the widely publicized results from Arlington. These proceedings contain the papers that were selected for presentation at the International Workshop, on Temporal Databases held in Zurich, Switzerland on 17-18 September 1995.

The research fields of "artificial intelligence and music" and "cognitive musicology" are relative newcomers to the many interdisciplinary groupings based around the centre of AI and cognitive science. They are concerned with the computational study and emulation of human behaviour with respect to music, in many aspects, and with varying degrees of emphasis on psychological plausibility. Recent publications have included work in such diverse areas as rhythm and pitch perception, performance, composition, and formal analysis. Music shares with language the property of giving access to human mental behaviour in a very direct way. As such, it has the potential to be a very useful domain for AI work. Furthermore, in the course of time, AI related work will surely throw light back onto some or all of the fields to which it is applied. Indeed, we are already beginning to feel the benefits of the application of AI techniques to music technology. It is not surprising, therefore, that one of the first areas interest for of musical AI study is that of music education. There are many ways in which an artificial intelligence or cognitive science approach to music education may be applied - for example, to automate tuition, to explain learning processes, to provide metaphors for human computer interaction, and so on. This collection of papers, which is intended to give an impression of both the breadth and depth of the field, originated from a workshop entitled "Music Education: An Artificial Intelligence Approach".

The Fourth International Workshop on Database Programming Languages - Object Models and Languages (DBPL-4) took place in Manhattan, New York City, 30 August-1 September 1993. The areas of interest and the format of DBPL-4 focused on the integration of programming languages, object models, type systems and database systems. As in the previous DBPL workshops, the setting was informal, allowing the participants to actively discuss and argue about the ideas presented in the talks. The comments and remarks made by the participants during and after the presentations were taken into account in the preparation of the final versions of the papers. The result, we believe, is a set of excellent papers. The DBPL sequence is closely related to the sequence of International Workshops on Persistent Object Systems (POS), first started in 1985. While the DBPL workshops focus on language and model issues, the POS workshops have focused on implementation issues; thus the two sequences complement each other. Many researchers participate in both workshop series. The eight sessions of the technical program of DBPL-4 were as follows: 1. Bulk types and their query languages (two sessions). 2. Object models and languages. 3. Data types with order. 4. Mechanisms to support persistence, reflection, and extensibility. 5. Query optimization and integrity constraints. 6. Logic-based models. 7. Implementation and performance issues.