4th Refinement Workshop


Book Description

This volume contains the proceedings ofthe 4th Refinement Workshop which was organised by the British Computer Society specialist group in Formal Aspects of Computing Science and held in Wolfson College, Cambridge, on 9-11 January, 1991. The term refinement embraces the theory and practice of using formal methods for specifying and implementing hardware and software. Most of the achievements to date in the field have been in developing the theoretical framework for mathematical approaches to programming, and on the practical side in formally specifying software, while more recently we have seen the development of practical approaches to deriving programs from their speCifications. The workshop gives a fair picture of the state of the art: it presents new theories for reasoning about software and hardware and case studies in applying known theory to interesting small-and medium-scale problems. We hope the book will be Of interest both to researchers in formal methods, and to software engineers in industry who want to keep abreast of possible applications of formal methods in industry. The programme consisted both of invited talks and refereed papers. The invited speakers were Ib S0rensen, Jean-Raymond Abrial, Donald MacKenzie, Ralph Back, Robert Milne, Mike Read, Mike Gordon, and Robert Worden who gave the introductory talk. This is the first refinement workshop that solicited papers for refereeing, and despite a rather late call for papers the response was excellent.




6th Refinement Workshop


Book Description

The Sixth Refinement Workshop took place at City University in London from 5th to 7th January 1994. The present volume includes all of the papers which were submitted and accepted for presentation, together with two papers by invited speakers. The workshops in the series have generally occurred at one year intervals but in this last case a two year period had elapsed. These workshops have established themselves as an important event in the calendar for all those who are interested in progress in the underlying theory of refinement and in the take-up by industry of the methods supported by that theory. One of the proposed themes of the sixth workshop was the reporting of successful adoption in industry of rigorous software development methods. The programme committee was perhaps slightly disappointed by the response from industry to the call in this respect. However, the recent period could be characterised as one of consolidation, when those companies which have made the decision that formal development methods are important to their business have been adopting them where appropriate and finding them to be worthwhile. On the other hand,. the difficult economic climate which exists in most parts of the developed world is perhaps not the context within which companies still dubious about the benefits are goil'\g to opt for making major changes in their working practices.




IV Higher Order Workshop, Banff 1990


Book Description

It is many years since Landin, Burge and others showed us how to apply higher order techniques and thus laid some foundations for modern functional programming. The advantage of higher order descriptions - that they can be very succinct and clear - has been percolating through ever since. Current research topics range from the design, implementation and use of higher order proof assistants and theorem provers, through program specification and verification, and programming language design, to its applications in hardware description and verification. The papers in this book represent the presentations made at a workshop held at Banff, Canada, September 10-14 1990 and organised by the Computer Science Department of the University of Calgary. The workshop gathered together researchers interested in applying higher order techniques to a range of problems. The workshop format had a few (but fairly long) presentations per day. This left ample time for healthy discussion and argument, many of which continued on into the small hours. With so much to choose from, the program had to be selective. This year's workshop was divided into five parts: 1. Expressing and reasoning about concurrency: Warren Burton and Ken Jackson, John Hughes, and Faron Moller. 2. Reasoning about synchronous circuits: Geraint Jones and Mary Sheeran (with a bonus on the fast Fourier transform from Geraint). 3. Reasoning about asynchronous circuits: Albert Camilleri, Jo Ebergen, and Martin Rem. 4. Categorical concepts for programming languages: Robin Cockett, Barry Jay, and Andy Pitts.




Database Programming Languages (DBPL-4)


Book Description

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.




Z User Workshop, York 1991


Book Description

In ordinary mathematics, an equation can be written down which is syntactically correct, but for which no solution exists. For example, consider the equation x = x + 1 defined over the real numbers; there is no value of x which satisfies it. Similarly it is possible to specify objects using the formal specification language Z [3,4], which can not possibly exist. Such specifications are called inconsistent and can arise in a number of ways. Example 1 The following Z specification of a functionf, from integers to integers "f x : ~ 1 x ~ O· fx = x + 1 (i) "f x : ~ 1 x ~ O· fx = x + 2 (ii) is inconsistent, because axiom (i) gives f 0 = 1, while axiom (ii) gives f 0 = 2. This contradicts the fact that f was declared as a function, that is, f must have a unique result when applied to an argument. Hence no suchfexists. Furthermore, iff 0 = 1 andfO = 2 then 1 = 2 can be deduced! From 1 = 2 anything can be deduced, thus showing the danger of an inconsistent specification. Note that all examples and proofs start with the word Example or Proof and end with the symbol.1.




Z User Workshop, Cambridge 1994


Book Description

This volume contains papers from the Eighth Z User Meeting, to be held at the University of Cambridge from 29 - 30 June 1994. The papers cover a wide range of issues associated with Z and formal methods, with particular reference to practical application. These issues include education, standards, tool support, and interaction with other design paradigms such as consideration of real-time and object-oriented approaches to development. Among the actual topics covered are: the formal specification in Z of Defence Standard 00-56; formal specification of telephone features; specifying and interpreting class hierarchies in Z; and software quality assurance using the SAZ method. Z User Workshop, Cambridge 1994 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.




Z User Workshop, London 1992


Book Description

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.




First International Workshop on Larch


Book Description

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.




Z User Workshop, Oxford 1990


Book Description




Advances in Databases and Information Systems


Book Description

This volume results from the regular sessions of the Second International Workshop of the Moscow ACM SIGMOD Chapter "Advances in Databases and Information Systems" (ADBIS'95) that took place 27th-30th June 1995, in Moscow, Russia. ADBIS'95 continues a series of annual Workshops on Advances in Databases and Information Systems organized by the Moscow ACM SIGMOD Chapter in cooperation with the Russian Founda tion for Basic Research. Past successful ADBIS conferences include the ADBIS'93 and ADBIS'94 Workshops that took place in Moscow. The aims of these workshops are to provide a forum for the presentation and in-depth discussion of advanced research directions that will effectively improve the building and use of future information systems and to increase communication between the Eastern and Western research communities which were formerly separated and still have only rare possibilities to interact. Improving of the contacts and exchange of ideas between researchers from the East and from the West will eventually lead to better collaboration between them. The ADBIS'95 Call for Submissions attracted 60 submissions from 15 countries of which 35 submissions were accepted for presentation at the regular sessions, 9 as posters, and 7 as presentations for a special session for the Information Systems for Science. This volume contains the papers presented in the regular sessions.