Object-Oriented Behavioral Specifications encourages builders of complex information systems to accelerate their move to using the approach of a scientific discipline in analysis rather than the approach of a craft. The focus is on understanding customers' needs and on precise specification of understanding gained through analysis. Specifications must bridge any gaps in understanding about business rules among customers, Subject Matter Experts, and `computer people', must inform decisions about reuse of software and systems, and must enable review of semantics over time. Specifications need to describe semantics rather than syntax, and to do that in an abstract and precise manner, in order to create software systems that satisfy business rules. The papers in this book show various ways of designing elegant and clear specifications which are reusable, lead to savings of intellectual effort, time, and money, and which contribute to the reliability of software and systems. Object-Oriented Behavioral Specifications offers a fresh treatment of the object-oriented paradigm by examining the limitations of traditional OO methodologies and by describing the significance of competing trends in OO modeling. The book builds on four years of successful OOPSLA workshops (1991-1995) on behavior semantics. This book deals with precise specifications of `what' is accomplished by the business and `what' is to be done by a system. The book includes descriptions of successful use of abstract and precise specification in industry. It draws on the experience of experts from industrial and academic settings and benefits from international participation. Collective behavior, neglected in some treatment of the OO paradigm, is addressed explicitly in this book. The book does not take `reuse' of specifications or software for granted, but furnishes a foundation for taking as rigorous an approach to reuse decisions as to precise specifications in original developments.

This text is an introduction to programming in general, and a manual for programming with the language Modula-2 in particular. It is oriented primarily towards people who have already acquired some basic knowledge of programming and would like to deepen their understanding in a more structured way. Neveltheless, an introductory chapter is included for the benefit of the beginner, displaying in a concise form some of the fundamental concepts of computers and their programming. The text is therefore also suitable as a self-contained tutorial. The notation used is Modula-2, which lends itself well for a structured approach and leads the student to a working style that has generally become known under the title of structured programming. As a manual for programming in Modula-2, the text covers practically all facilities of that language. Part 1 covers the basic notions of the variable, expression, assignment, conditional and repetitive statement, and array data structure. Together with Palt 2 which introduces the important concept of the procedure or subroutine, it contains essentially the material commonly discussed in introductory programming courses. Part 3 concerns data types and structures and constitutes the essence of an advanced course on programming. Palt 4 introduces the notion of the module, a concept that is fundamental to the design of larger programmed systems and to programming as team work. The most commonly used utility programs for input and output are presented as examples of modules.

At least four research fields detennine the theoretical background of specification and deduction in computer science: recursion theory, automated theorem proving, abstract data types and tenn rewriting systems. As these areas approach each other more and more, the strong distinctions between functional and relational views, deductive and denotational approaches as well as between specification and programming are relieved in favour of their integration. The book will not expose the lines of this development; conversely, it starts out from the nucleus of Hom clause logic and brings forth both known and unknown results, most of which affect more than one of the fields mentioned above. Chapter 1 touches on historical issues of specification and prototyping and delimits the topics handled in this book from others which are at the core of related work. Chapter 2 provides the fundamental notions and notations needed for the presentation and interpretation of many-sorted Horn clause theories with equality. Chapter 3 supplies a number of sample Hom clause specifications ranging from arithmetic through string manipulation to higher data structures and interpreters of programming languages. Some of these examples serve as a reference to illustrate definitions and results, others may throw a light on the strong link between specifications and programs, which are executed by applying deduction rules. Thus we have included examples of how to use program trans/ormation methods in specification design.

" .. .1 always worked with programming languages because it seemed to me that until you could understand those, you really couldn't understand computers. Understanding them doesn't really mean only being able to use them. A lot of people can use them without understanding them." Christopher Strachey The development of programming languages is one of the finest intellectual achievements of the new discipline called Computer Science. And yet, there is no other subject that I know of, that has such emotionalism and mystique associated with it. Thus, my attempt to write about this highly charged subject is taken with a good deal of in my role as professor I have felt the need for a caution. Nevertheless, modern treatment of this subject. Traditional books on programming languages are like abbreviated language manuals, but this book takes a fundamentally different point of view. I believe that the best possible way to study and understand today's programming languages is by focusing on a few essential concepts. These concepts form the outline for this book and include such topics as variables, expressions, statements, typing, scope, procedures, data types, exception handling and concurrency. By understanding what these concepts are and how they are realized in different programming languages, one arrives at a level of comprehension far greater than one gets by writing some programs in a xii Preface few languages. Moreover, knowledge of these concepts provides a framework for understanding future language designs.

When I compare the books on expert systems in my library with the production expert systems I know of, I note that there are few good books on building expert systems in Prolog. Of course, the set of actual production systems is a little small for a valid statistical sample, at least at the time and place of this writing - here in Gennany, and in the first days of 1989. But there are at least some systems I have seen running in real life commercial and industrial environments, and not only at trade shows. I can observe the most impressive one in my immediate neighborhood. It is installed in the Telephone Shop of the Gennan Federal PTT near the Munich National Theater, and helps configure telephone systems and small PBXs for mostly private customers. It has a neat, graphical interface, and constructs and prices an individual telephone installation interactively before the very eyes of the customer. The hidden features of the system are even more impressive. It is part of an expert system network with a distributed knowledge base that will grow to about 150 installations in every Telephone Shop throughout Gennany. Each of them can be updated individually overnight via Teletex to present special offers or to adapt the selection process to the hardware supplies currently available at the local ware houses."

This book constitutes the refereed proceedings of the 15th Brazilian Symposium on Formal Methods, SBMF 2012, held in Natal, Brazil, in September 2012; co-located with CBSoft 2012, the Third Brazilian Conference on Software: Theory and Practice. The 14 revised full papers presented together with 2 keynotes were carefully reviewed and selected from 29 submissions. The papers presented cover a broad range of foundational and methodological issues in formal methods for the design and analysis of software and hardware systems as well as applications in various domains.

The title of this book contains the words ALGORITHMIC LANGUAGE, in the singular. This is meant to convey the idea that it deals not so much with the diversity of program ming languages, but rather with their commonalities. The task of formal program develop It allows classifying ment proved to be the ideal frame for demonstrating this unity. concepts and distinguishing fundamental notions from notational features; and it leads immediately to a systematic disposition. This approach is supported by didactic, practical, and theoretical considerations. The clarity of the structure of a programming language de signed according to the principles of program transformation is remarkable. Of course there are various notations for such a language. The notation used in this book is mainly oriented towards ALGOL 68, but is also strongly influenced by PASCAL - it could equally well have been the other way round. In the appendices there are occa sional references to the styles used in ALGOL, PASCAL, LISP, and elsewhere."

This book constitutes the proceedings of the 16th International Conference on Foundations of Software Science and Computational Structures, FOSSACS 2013, held as part of the Joint European Conferences on Theory and Practice of Software, ETAPS 2013, which took place in Rome, Italy, in March 2013 The 28 papers presented in this volume were carefully reviewed and selected from 109 submissions. They are organized in topical sections named: models of computation; reasoning about processes; bisimulation; modal and higher-order logics; reasoning about programs; computational complexity; quantitative models; and categorical models.

This Festschrift volume, published in honor of Carolyn Talcott on the occasion of her 70th birthday, contains a collection of papers presented at a symposium held in Menlo Park, California, USA, in November 2011. Carolyn Talcott is a leading researcher and mentor of international renown among computer scientists. She has made key contributions to a number of areas of computer science including: semantics and verification of progamming languages; foundations of actor-based systems; middleware, meta-architectures, and systems; Maude and rewriting logic; and computational biology. The 21 papers presented are organized in topical sections named: Essays on Carolyn Talcott; actors and programming languages; cyberphysical systems; middleware and meta-architectures; formal methods and reasoning tools; and computational biology.

Visual languages have long been lit pursuitofeffective communication 00 tween human and machine. Today, they are suecessfully employed for e: nd user progmmming, modeliog, rapid prototypmg, and design activities by people ofmany disciplines including arehitects, artists, children, engi neers, and scientists. Furthermore. with rapid advances ofthe Internet and Web technology, human human communication through the Web or eleo tronie mobile deviees is becoming more and moreprevalent This manuscript provides a comprehensive introduetion to diagmmmatiooI visual programming languages and the technologyofautomatie genemtion ofsnch languages. It covers a broad rangeofcontents from the underlying theoryofgraph grammars to the applications in various domains. Thecon tents were ex: l: l: aeted from the papers that my Ph. D. students and I have published in the last 10 years. and are updated and organized in a coherent fashion. The manuseript gives an in. -depth treatmentof all the topic areas. Pointers to related work and further readings are also faeilitated at the end ofeverychapterexeeptChapter 9. Rather than describing how to program visually, the manuscript discusses what are visual programming languages, and how sooh languages and their underlying foundations can be usefully applied to other fields incomputer science that need graphs as the p: rimary meansofrepresentation. Assuming the basic knowledge of computer programming and compiler co: nstruetion, the manuscript can be used as a textbook for senior orgradu ate computer science classes on visual languages, or a reference book for programming language classes, practitioners, and researchers inthe related field. The manuscript cannot be completed without the helps of many people.

GPSS-FORTRAN is a simulator for the simulation of discrete, continuous, and combined models. Provides a reference for GPSS-FORTRAN Version 3 and illustrates the use of the lan- guage by numerous examples.

Since the early seventies concepts of specification have become central in the whole area of computer science. Especially algebraic specification techniques for abstract data types and software systems have gained considerable importance in recent years. They have not only played a central role in the theory of data type specification, but meanwhile have had a remarkable influence on programming language design, system architectures, arid software tools and environments. The fundamentals of algebraic specification lay a basis for teaching, research, and development in all those fields of computer science where algebraic techniques are the subject or are used with advantage on a conceptual level. Such a basis, however, we do not regard to be a synopsis of all the different approaches and achievements but rather a consistently developed theory. Such a theory should mainly emphasize elaboration of basic concepts from one point of view and, in a rigorous way, reach the state of the art in the field. We understand fundamentals in this context as: 1. Fundamentals in the sense of a carefully motivated introduction to algebraic specification, which is understandable for computer scientists and mathematicians. 2. Fundamentals in the sense of mathematical theories which are the basis for precise definitions, constructions, results, and correctness proofs. 3. Fundamentals in the sense of concepts from computer science, which are introduced on a conceptual level and formalized in mathematical terms.

First published in 1998, this textbook is a broad but rigourous survey of the theoretical basis for the design, definition and implementation of programming languages and of systems for specifying and proving programme behaviour. Both imperative and functional programming are covered, as well as the ways of integrating these aspects into more general languages. Recognising a unity of technique beneath the diversity of research in programming languages, the author presents an integrated treatment of the basic principles of the subject. He identifies the relatively small number of concepts, such as compositional semantics, binding structure, domains, transition systems and inference rules, that serve as the foundation of the field. Assuming only knowledge of elementary programming and mathematics, this text is perfect for advanced undergraduate and beginning graduate courses in programming language theory and also will appeal to researchers and professionals in designing or implementing computer languages.

This book is an updated version of my Ph.D. dissertation, The AND/OR Process Model for Parallel Interpretation of Logic Programs. The three years since that paper was finished (or so I thought then) have seen quite a bit of work in the area of parallel execution models and programming languages for logic programs. A quick glance at the bibliography here shows roughly 50 papers on these topics, 40 of which were published after 1983. The main difference between the book and the dissertation is the updated survey of related work. One of the appendices in the dissertation was an overview of a Prolog implementation of an interpreter based on the AND/OR Process Model, a simulator I used to get some preliminary measurements of parallelism in logic programs. In the last three years I have been involved with three other implementations. One was written in C and is now being installed on a small multiprocessor at the University of Oregon. Most of the programming of this interpreter was done by Nitin More under my direction for his M.S. project. The other two, one written in Multilisp and the other in Modula-2, are more limited, intended to test ideas about implementing specific aspects of the model. Instead of an appendix describing one interpreter, this book has more detail about implementation included in Chapters 5 through 7, based on a combination of ideas from the four interpreters.

The growing demand for systems of ever-increasing complexity and precision has stimulated the need for higher level concepts, tools, and techniques in every area of Computer Science. Some of these areas, in particular Artificial Intelligence, Databases, and Programming Lan guages, are attempting to meet this demand by defining a new, more abstract level of system description. We call this new level conceptual in recognition of its basic conceptual nature. In Artificial Intelligence, the problem of designing an expert system is seen primarily as a problem of building a knowledge base that repre sents knowledge about an enterprise. Consequently, Knowledge Repre sentation is viewed as a central issue in Artificial Intelligence research. Database design methodologies developed during the last five years are almost unanimous in offering semantic data models in terms of which the designer directly and naturally models an enterprise before proceed ing to a detailed logical and physical database design. In Programming Languages, different forms of abstraction which allow implementation independent specifications of data, functions, and control have been a major research theme for a decade. To emphasize the common goals of these three research efforts, we call this new activity conceptual modelling."

The microcomputer has put a vast amount of computational power in the hands of the practicing chemical engineer. However, a microcomputer is of little use unless there are programs available to solve chemical engineer ing problems; In this book, I have put together a collection of BASIC pro grams that w~ll help the practicing engineer be more productive and able to solve complex problems that are normally handled on mainframe com puters. The plant engineer will find the book particularly useful. The plant en gineer is calle~ upon to investigate problems that range from simple trouble shooting to tQe detailed design of complex chemical plants. The larger proj ects are usually add-on jobs to the regular duties of keeping a chemical plant running. In t~day's business climate, answers to problems must be obtained quickly and ~ccurately. The computer is capable of testing hypothesis, thereby allo~ing engineers to evaluate alternative solutions to problems quickly and provide answers to management's questions that invariably shift like the sand~ in a desert.

The NeWS Book leads the technical reader through the discovery of a revolutionary window system: the Network extensible Window System, developed by Sun Microsystems. Independent of computer hardware and systems software, NeWS has been ported to a number of platforms and licensed to many computer vendors and software developers. NeWS will be part of the standard UNIX distribution from AT&T in the future as it is combined with the well-known X Window System from MIT in the X11/NeWS product. The specifications are in the public domain. Based on the popular PostScript page description language, NeWS provides a uniquely extensible interpretive programming environment for application developers in a networked graphics and window system environment. Networking is integral to NeWS; NeWS-based programs may span a heterogeneous set of distributed sites. NeWS is the first system to extend the PostScript language's already wide acceptance in printing applications into the realm of graphics and window-based applications. The NeWS Book is intended for a technical audience who may or may not have experience with window system design and programming.It gives practical examples of how to write PostScript programs, that implement interactive user interface techniques, while also exploring how the advanced imaging of the PostScript language model applies to the display as well as the printer. UNIX, NeWS, and graphics programmers, developers of graphical applications, computer science students, PostScript language devotees in desktop publishing, and sophisticated end-users who want to understand leading-edge solutions in window system design all will benefit from The NeWS Book.

I am very pleased to write these few brief paragraphs introducing this book, and would like to take this opportunity to attempt to set the Toolpack project in an appropriate historical context. The Toolpack project must be considered to have actually began in the Fall of 1978, when Prof. Webb C. Miller, at a meeting at Jet Propulsion Laboratories in Pasadena, California, suggested that there be a large-scale project, called Toolpack, aimed at pulling together a comprehensive collection of mathematical software development tools. It was suggested that the project follow the pattern of other "Pack" projects, such as Eispack, Linpack, and Funpack which had assembled and systematized comprehensive collections of mathematical software in such areas as eigenvalue computation, linear equation solution and special function approximation. From the that the Toolpack project would differ significantly from beginning it was recognized these earlier "Pack" projects in that it was attempting to assemble and systematize software in an area which was not well established and understood. Thus it was not clear how to organize and integrate the tools we were to collect into Toolpack. As a consequence Toolpack became simultaneously a research project and a development project. The research was aimed at determining effective strategies for large-scale integration of large-scale software tools, and the development project was aimed at implementing these strategies and using them to put high quality tools at the disposal of working mathematical software writers.

Accompanying the book, as with all TELOS sponsored publications, is an electronic component. In this case it is a DOS-Diskette produced by one of the coauthors, Paul Wellin. This diskette consists of "Mathematica "notebooks and packages which contain the codes for all examples and exercises in the book, as well as additional materials intended to extend many ideas covered in the text. It is of great value to teachers, students, and others using this book to learn how to effectively program with "Mathematica" .

Distributed computer systems are now widely available but, despite a number of recent advances, the design of software for these systems remains a challenging task, involving two main difficulties: the absence of a shared clock and the absence of a shared memory. The absence of a shared clock means that the concept of time is not useful in distributed systems. The absence of shared memory implies that the concept of a state of a distributed system also needs to be redefined. These two important concepts occupy a major portion of this book. Principles of Distributed Systems describes tools and techniques that have been successfully applied to tackle the problem of global time and state in distributed systems. The author demonstrates that the concept of time can be replaced by that of causality, and clocks can be constructed to provide causality information. The problem of not having a global state is alleviated by developing efficient algorithms for detecting properties and computing global functions. The author's major emphasis is in developing general mechanisms that can be applied to a variety of problems. For example, instead of discussing algorithms for standard problems, such as termination detection and deadlocks, the book discusses algorithms to detect general properties of a distributed computation. Also included are several worked examples and exercise problems that can be used for individual practice and classroom instruction. Audience: Can be used to teach a one-semester graduate course on distributed systems. Also an invaluable reference book for researchers and practitioners working on the many different aspects of distributed systems.

This book constitutes revised papers of the proceedings of the 7th International Workshop on System Analysis and Modeling, SAM 2012, held in Innsbruck, Austria, in October 2012. The 12 papers presented were carefully reviewed and selected from 27 submissions. In addition, the book contains two keynote speeches in full-paper length. The contributions are organized in topical sections named: test and analysis, language enhancements, fuzzy subjects, components and composition, and configuring and product lines.

This book constitutes the thoroughly refereed post-conference proceedings of the 14th Brazilian Symposium on Formal Methods, SBMF 2011, held in Sao Paulo, Brazil, in September 2011; co-located with CBSoft 2011, the second Brazilian Conference on Software: Theory and Practice. The 13 revised full papers were carefully reviewed and selected from 37 submissions. The papers presented cover a broad range of foundational and methodological issues in formal methods for the design and analysis of software and hardware systems as well as applications in various domains.

Natural language generation is a field within artificial intelligence which looks ahead to the future when machines will communicate complex thoughts to their human users in a natural way. Generation systems supply the sophisticated knowledge about natural languages that must come into play when one needs to use wordings that will overpower techniques based only on symbolic string manipulation techniques. Topics covered in this volume include discourse theory, mechanical translation, deliberate writing, and revision. "Natural Language Generation Systems" contains contributions by leading researchers in the field. Chapters contain details of grammatical treatments and processing seldom reported on outside of full length monographs.

This book constitutes the thoroughly refereed post-conference proceedings of the 11th International Symposium on Trends in Functional Programming, TFP 2010, held in Norman, OK, USA, in May 2010. The 13 revised full papers presented were carefully reviewed and selected from 26 submissions during two rounds of reviewing and improvement. The papers cover new ideas for refactoring, managing source-code complexity, functional language implementation, graphical languages, applications of functional programming in pure mathematics, type theory, multitasking and parallel processing, distributed systems, scientific modeling, domain specific languages, hardware design, education, and testing.