Crystal Structure Refinement is a mixture of textbook and tutorial. As A Crystallographers Guide to SHELXL it covers advanced aspects of practical crystal structure refinement, which have not been much addressed by textbooks so far. After an introduction to SHELXL in the first chapter, a brief survey of crystal structure refinement is provided. Chapters three and higher address the various aspects of structure refinement, from the treatment of hydrogen atoms to the assignment of atom types, to disorder, to non-crystallographic symmetry and twinning. One chapter is dedicated to the refinement of macromolecular structures and two short chapters deal with structure validation (one for small molecule structures and one for macromolecules). In each of the chapters the book gives refinement examples, based on the program SHELXL, describing every problem in detail. It comes with a CD-ROM with all files necessary to reproduce the refinements.

The Pleasures of the Imagination examines the birth and development of English "high culture" in the eighteenth century. It charts the growth of a literary and artistic world fostered by publishers, theatrical and musical impresarios, picture dealers and auctioneers, and presented to th public in coffee-houses, concert halls, libraries, theatres and pleasure gardens. In 1660, there were few professional authors, musicians and painters, no public concert series, galleries, newspaper critics or reviews. By the dawn of the nineteenth century they were all aprt of the cultural life of the nation. John Brewer's enthralling book explains how this happened and recreates the world in which the great works of English eighteenth-century art were made. Its purpose is to show how literature, painting, music and the theatre were communicated to a public increasingly avid for them. It explores the alleys and garrets of Grub Street, rummages the shelves of bookshops and libraries, peers through printsellers' shop windows and into artists' studios, and slips behind the scenes at Drury Lane and Covent Garden. It takes us out of Gay and Boswell's London to visit the debating clubs, poetry circles, ballrooms, concert halls, music festivals, theatres and assemblies that made the culture of English provincial towns, and shows us how the national landscape became one of Britain's greatest cultural treasures. It reveals to us a picture of English artistic and literary life in the eighteenth century less familiar, but more suprising, more various and more convincing than any we have seen before.

The Idea of Program Refinement Programs are complex. They are typically so complex, that they go beyond the full comprehension even of the programmer or team who designed them, with all the consequences this has. How can we cope with such complexity in a satisfactory way? An approach, advocated for a long time, is to separate a concise specification of a program - the "what" - from a possibly involved implementation - the "how". Once a specification is obtained from the set of requirements on the program, there can still be a large gap to an efficient implementation. The development from specification to implementation can then proceed by a succession oflayers, such that each layer is a refinement of the previous one. Design decisions can be introduced in refinement steps one at a time. By this, the refinement steps can be kept small and manageable. Still, the set of all requirements can be far too large to be taken completely into account in the initial specification. Even if they could, they might obscure issues more than clarify them. For example: • An information system for stored goods needs to produce an error message on il legal input. Yet, the exact wording - and even the language - of those messages is irrelevant for an understanding of the essence of the system. • A banking application interacts with customers with a graphical interface. Yet the specification of the graphical layout is secondary compared to the specification of the possible transactions.

Refinement is one of the cornerstones of the formal approach to software engineering, and its use in various domains has led to research on new applications and generalisation. This book brings together this important research in one volume, with the addition of examples drawn from different application areas. It covers four main themes: Data refinement and its application to Z Generalisations of refinement that change the interface and atomicity of operations Refinement in Object-Z Modelling state and behaviour by combining Object-Z with CSP Refinement in Z and Object-Z: Foundations and Advanced Applications provides an invaluable overview of recent research for academic and industrial researchers, lecturers teaching formal specification and development, industrial practitioners using formal methods in their work, and postgraduate and advanced undergraduate students. This second edition is a comprehensive update to the first and includes the following new material: Early chapters have been extended to also include trace refinement, based directly on partial relations rather than through totalisation Provides an updated discussion on divergence, non-atomic refinements and approximate refinement Includes a discussion of the differing semantics of operations and outputs and how they affect the abstraction of models written using Object-Z and CSP Presents a fuller account of the relationship between relational refinement and various models of refinement in CSP Bibliographic notes at the end of each chapter have been extended with the most up to date citations and research