This collection of reprints describes a unified treatment of semantics, covering a wide range of notions in parallel languages. Included are several foundational and introductory papers developing the methodology of metric semantics, studies on the comparative semantics of parallel object-oriented and logic programming, and papers on full abstraction and transition system specifications. In addition, links with process algebra and the theory of domain equations are established. Throughout, a uniform proof technique is used to relate operational and denotational models. The approach is flexible in that both linear time, branching time (or bisimulation) and intermediate models can be handled, as well as schematic and interpreted elementary actions. The reprints are preceded by an extensive introduction surveying related work on metric semantics.

The semantics of concurrent systems is one of the most vigorous areas of research in theoretical computer science, but suffers from disagree ment due to different, and often incompatible, attitudes towards abstracting non-sequential behaviour. When confronted with process algebras, which give rise to very elegant, highly abstract and com positional models, traditionally based on the interleaving abstraction, some argue that the wealth of contribution they have made is partially offset by the difficulty in dealing with topics such as faimess. On the other hand, the non-interleaving approaches, based on causality, although easing problems with fairness and confusion, still lack struc ture, compositionality, and the elegance of the interleaving counter parts. Since both these approaches have undoubtedly provided important contributions towards understanding of concurrent systems, one should concentrate on what they have in common, rather than the way they differ. The Intemational Workshop on Semantics for Concurrency held at the University of Leicester on 23-25 July 1990 was organised to help overcome this problem. Its main objective was not to be divisive, but rather to encourage discussions leading towards the identification of the positive objective features of the main approaches, in the hope of furthering common understanding. The Workshop met with an excel lent response, and attracted contributions from all over the world. The result was an interesting and varied programme, which was a combi nation of invited and refereed papers. The invited speakers were: Prof. dr. E. Best (Hildesheim University) Prof. dr. A.

This book constitutes the refereed proceedings of the 15th International Conference on Concurrency Theory, CONCUR 2004, held in London, UK in August/September 2004. The 29 revised full papers presented together with 4 invited papers were carefully reviewed and selected from 134 submissions. Among the topics covered are concurrency related aspects of models of computation, semantic domains, process algebras, Petri nets, event structures, real-time systems, hybrid systems, decidability, model checking, verification techniques, refinement, term and graph rewriting, distributed programming, constraint logic programming, object-oriented programming, typing systems and algorithms, case studies, tools, and environments for programming and verification.

The semantics of concurrent systems is one of the most vigorous areas of research in theoretical computer science, but suffers from disagree ment due to different, and often incompatible, attitudes towards abstracting non-sequential behaviour. When confronted with process algebras, which give rise to very elegant, highly abstract and com positional models, traditionally based on the interleaving abstraction, some argue that the wealth of contribution they have made is partially offset by the difficulty in dealing with topics such as faimess. On the other hand, the non-interleaving approaches, based on causality, although easing problems with fairness and confusion, still lack struc ture, compositionality, and the elegance of the interleaving counter parts. Since both these approaches have undoubtedly provided important contributions towards understanding of concurrent systems, one should concentrate on what they have in common, rather than the way they differ. The Intemational Workshop on Semantics for Concurrency held at the University of Leicester on 23-25 July 1990 was organised to help overcome this problem. Its main objective was not to be divisive, but rather to encourage discussions leading towards the identification of the positive objective features of the main approaches, in the hope of furthering common understanding. The Workshop met with an excel lent response, and attracted contributions from all over the world. The result was an interesting and varied programme, which was a combi nation of invited and refereed papers. The invited speakers were: Prof. dr. E. Best (Hildesheim University) Prof. dr. A.

This volume contains the proceedings of the 1990 Spring School of Theoretical Computer Science, devoted to the semantics of concurrency. The papers are of two kinds: - surveys and tutorials introducing the subject to novices and students and giving updates of the state of the art, - research papers presenting recent achievements in the semantics of concurrency. The contributions explicate the connections, similarities and differences between various approaches to the semantics of concurrency, such as pomsets and metric semantics, event structures, synchronization trees, fixpoints and languages, traces, CCS and Petri nets, and categorical models. They also cover and compare the various notions of observation and bisimulation equivalences, logics for concurrency, and applications to dis- tributed systems.

Offers information on how to exploit the parallel architectures in a computer's GPU to improve code performance, scalability, and resilience.