Egon Börger – författare

Structures of Computing explains the behavioral meaning of fundamental concepts of computing from a practical viewpoint and in generic terms, unrestricted by specific computing devices or programming languages. To compute is understood as processing structures by a set of cooperating agents each of which executes an algorithm assigned to it and interacts with the other agents.Part I of the book defines the conceptual constituents of interactive processes: (i) data, i.e. structured objects with associated properties, relations and functions the algorithmic processes operate upon, (ii) basic operations that affect the data in single execution steps, and (iii) control mechanisms that determine the combination of single steps in multi-agent computations where the interaction happens via communication or other forms of data sharing.Part II analyses these constituents concerning (i) methods to achieve process correctness (inspection, experimental validation, reasoning), (ii) principal computational paradigms (architectures, programming styles, communication structures, control patterns from sequential and reflective to concurrent, mixed synchronous/asynchronous and data flow control), and (iii) complexity (power and limits of computing structures).The book is mainly addressed to students and professionals who want to understand the conceptual foundation of computing. It does not assume any specific programming experience but only a basic understanding of what are mechanically executable processes and their descriptions. Any unnecessary formalism is thus avoided, and definitions are formulated as much as possible in natural language, using common mathematical notation only where needed to prevent ambiguities. Numerous examples and exercises serve as comprehension checkpoints.

Endlich liegt der ,,Klassiker" der Theoretischen Informatik, der Studenten und Forschern ein unentbehrliches Standardwerk ist, in neuer Auflage vor.

This book constitutes the refereed proceedings of the 10th International Workshop on Abstract State Machines, ASM 2003, held in Taormina, Italy in March 2003.The 16 revised full papers presented together with 8 invited papers and 12 abstracts were carefully reviewed and selected for inclusion in the book. The papers reflect the state of the art of the abstract state machine method for the design and analysis of complex software/hardware systems. Besides theoretical results and methodological progress, application in various fields are studied as well.

The systems engineering method proposed in this book, which is based on Abstract State Machines (ASMs), guides the development of software and embedded hardware-software systems seamlessly from requirements capture to actual implementation and documentation. The method bridges the gap between the human understanding and formulation of real-world problems and the deployment of their algorithmic solutions by code-executing machines. Within a single conceptual framework it covers design, verification by reasoning techniques, and validation by simulation and testing. ASMs improve current industrial practice by using accurate high-level modeling and by linking the descriptions at the successive stages of system development in an organic and efficiently maintainable chain of rigorous and coherent system models at stepwise-refined abstraction levels. In several industrial projects the ASM method has proven its superiority compared to the popular UML methodology when designing complex parallel or dynamic systems.This book combines the features of a textbook and a handbook: the reader will find detailed explanations, proofs, and exercises as well as numerous examples and real-world case studies. Researchers will find here the most comprehensive description of ASMs available today and professionals will use it as a "modeling handbook for the working software engineer. " As a textbook it supports self-study or it can form the basis of a lecture course. The book is complemented by a CD containing the whole book text, additional course material, solutions to exercises, and additional examples. Even more information can be found on the related website maintained by the authors: http://www. di. unipi. it/AsmBook/

This volume contains 37 invited research papers collected in memory of Dieter Rödding, who is known for his work on the classification of recursive functions, on reduction classes, on the spectrum problem and on the complexity of cardinality quantifiers in predicate logic and in arithmetical hierarchy. He was one of the first to pursue the interaction of logic and computer science. The volume reflects the wide spectrum of Dieter Rödding's scientific interests.

This book provides a high-level description, together with a mathematical and an experimental analysis, of Java and of the Java Virtual Machine (JVM), including a standard compiler of Java programs to JVM code and the security critical bytecode verifier component of the JVM. The description is structured into language layers and machine components. It comes with a natural executable refinement (written in AsmGofer and provided on CD ROM) which can be used for testing code. The method developed for this purpose is based on Abstract State Machines (ASMs) and can be applied to other virtual machines and to other programming languages as well. The book is written for advanced students and for professionals and practitioners in research and development who need a complete and transparent definition and an executable model of the language and of the virtual machine underlying its intended implementation.The CD ROM contains the entire text of the book and numerous examples and exercises.

This is the most comprehensive treatment available in book form of the classical decision problem of mathematical logic and of the role of the classical decision problem in modern computer science. A revealing analysis of the natural order of decidable and undecidable cases is given. The complete classification of the solvable and unsolvable standard cases of the classical decision problem will be of particular interest to the reader. The classification comes complete with the complexity analysis of the solvable cases, with the comprehensive treatment of the reduction method, and with the model-theoretical analysis of solvable cases. Many cases are treated here for the first time, and a great number of simple proofs and exercises have been included. The results and methods of the book are extensively used in logic, computer science and artificial intelligence.

This volume contains the papers which were presented to the workshop "Computer-Science Logic" held in Karlsruhe on October 12-16, 1987. Traditionally Logic, or more specifically, Mathematical Logic splits into several subareas: Set Theory, Proof Theory, Recursion Theory, and Model Theory. In addition there is what sometimes is called Philosophical Logic which deals with topics like nonclassical logics and which for historical reasons has been developed mainly at philosphical departments rather than at mathematics institutions. Today Computer Science challenges Logic in a new way. The theoretical analysis of problems in Computer Science for intrinsic reasons has pointed back to Logic. A broad class of questions became visible which is of a basically logical nature. These questions are often related to some of the traditional disciplines of Logic but normally without being covered adequately by any of them. The novel and unifying aspect of this new branch of Logic is the algorithmic point of view which is based on experiences people had with computers. The aim of the "Computer-Science Logic" workshop and of this volume is to represent the richness of research activities in this field in the German-speaking countries and to point to their underlying general logical principles.

This volume contains the papers which were presented at the second workshop "Computer Science Logic" held in Duisburg, FRG, October 3-7, 1988. These proceedings cover a wide range of topics both from theoretical and applied areas of computer science. More specifically, the papers deal with problems arising at the border of logic and computer science: e.g. in complexity, data base theory, logic programming, artificial intelligence, and concurrency. The volume should be of interest to all logicians and computer scientists working in the above fields.

This volume contains the revised versions of 28 papers presented at the third workshop on Computer Science Logic held in Kaiserslautern, FRG, October 2-6, 1989. These proceedings cover a wide range of topics both from theoretical and applied areas of computer science. More specifically, the papers deal with problems arising at the border of logic and computer science, e.g. in complexity, data base theory, logic programming, artificial intelligece, and temporal logic. The volume should be of interest to all logicians and computer scientists working in the above field.

The workshop Computer Science Logic '90 was held at theMax-Planck-Haus in Heidelberg, Germany, October 1-5, 1990. It was the fourth in a series of worskhops, following CSL'89 at the University of Kaiserslautern (see LNCS 440), CSL'88 at the University of Duisberg (see LNCS 385), and CSL'87 at the University of Karlsruhe (see LNCS 329). Thisvolume contains 24 papers, chosen by means of a reviewprocedure from the 35 papers presented at the workshop, someof which were invited and some selected from a total of 89submissions. The papers cover a wide range of topics arisingfrom the applications of logic to computer science.

This volume presents the proceedings of the workshop CSL '91(Computer Science Logic) held at the University of Berne,Switzerland, October 7-11, 1991. This was the fifth in aseries of annual workshops on computer sciencelogic (thefirst four are recorded in LNCS volumes 329, 385, 440, and533). The volume contains 33 invited and selected papers on avariety of logical topics in computer science, includingabstract datatypes, bounded theories, complexity results,cut elimination, denotational semantics, infinitary queries,Kleene algebra with recursion, minimal proofs, normal formsin infinite-valued logic, ordinal processes, persistentPetri nets, plausibility logic, program synthesis systems,quantifier hierarchies, semantics of modularization, stablelogic, term rewriting systems, termination of logicprograms, transitive closure logic, variants of resolution,and many others.

This volume presents the proceedings of the Computer ScienceLogic Workshop CSL '92, held in Pisa, Italy, inSeptember/October 1992. CSL '92 was the sixth of the seriesand the first one held as Annual Conference of the EuropeanAssociation for Computer Science Logic (EACSL). Fullversions of the workshop contributions were collected aftertheir presentation and reviewed. On the basis of 58 reviews,26 papers were selected for publication, and appear here inrevised final form. Topics covered in the volume include: Turing machines,linear logic, logic of proofs, optimization problems, lambdacalculus, fixpoint logic, NP-completeness, resolution,transition system semantics, higher order partial functions,evolving algebras, functional logic programming, inductivedefinability, semantics of C, classes for a functionallanguage, NP-optimization problems, theory of types andnames, sconing and relators, 3-satisfiability, Kleene'sslash, negation-complete logic programs, polynomial-timeoracle machines, and monadic second-order properties.

This volume contains the final versions of a collection of papers presented at the Annual Conference of the European Association for Computer Science Logic, CSL '93, held at Swansea, UK in September 1993.The 21 full papers included were selected from a total of 62 submissions and essentially contribute to the whole area of computer science logic research. They are devoted to such topics as set constraints, lambda calculi, process algebras, program semantics, intuitionistic logics, fixed-point logics, the equivalence problem, Horn clauses, quantifiers, and proof tranformations.

This book, with the CD-ROM included, is the documentation of a unique collaborative effort in evaluating formal methods for usage under industrial constraints: the major techniques for formally supported specification, design, and verification of large programs and complex systems are applied to a non-trivial and non-academic problem which is typical for industrial informal requirements specifications.The 21 papers included in the book, together with an introduction and competition report, were selected from 33 candidate solutions. This book comes with a CD-ROM containing, besides the printed papers, executable code, full definitions of all parts of the specifications, and detailed descriptions of foundational matters where appropriate.

This book grew out of material which was taught at the International Summer School on Architecture Design and Validation Methods, held June 23-July 5, 1997, on the Island of Lipari and directed to graduate students and young researchers. Since then the course notes have been completely elaborated and extended and additional chapters have been added so that this book offers a comprehensive presentation of the state of the art which leads the reader to the forefront of the current research in the area. The chapters, each of which was written by a group of eminent special­ ists in the field, are self-contained and can be read independently of each other. They cover the wide range of theoretical and practical methods which currently used for the specification, design, validation and verification of are hardware/software architectures. Synthesis methods are the subject of the first three chapters. The chapter on Modeling and Synthesis of Behavior, Control and Data Flow focusses on techniques above the register-transfer level. The chapter on Cell-Based Logic Optimizations concentrates on methods that interface logic design with phys­ ical design, in particular on techniques for cell-library binding, the back-end of logic synthesis. The chapter on A Design Flow for Performance Planning presents new paradigms for iteration-free synthesis where global wire plans for meeting timing constraints already appear at the conceptual design stage, even before fixing the functionality of the blocks in the plan.

This book constitutes the refereed proceedings of the First International Conference of Abstract State Machines, B and Z, ABZ 2008, held in London, UK, in September 2008. The conference simultaneously incorporated the 15th International ASM Workshop, the 17th International Conference of Z Users and the 8th International Conference on the B Method. The 44 revised full papers presented together with 4 invited contributions were carefully reviewed and selected from numerous submissions. The conference fosters the cross-fertilization of three rigorous methods for the design and analysis of hardware and software systems - both in academia and industry - namely Abstract State Machines, B, and Z. Covering a wide range of research spanning from theoretical and methodological foundations to tool support and practical applications, the contributions are organized in topical sections on abstract state machines, B papers, Z papers, ABZ short papers, and the papers of the Verified Software Repository Network (VSR-net) workshop.

WorkonthisvolumestartedwiththeLipariSummerSchoolonAdvancesinSo- ware Engineering, which the ?rst editor organizedtogether with Alfredo Ferro fromtheUniversityofCataniainJuly2007.Itwasthe19thinawell-knownse- 1 riesofannualinternationalschools,addressedatcomputerscienceresearchers. Thethemesofthecourses,offourone-hourlectureseach,rangedfromdomain andrequirementsengineering(DinesBjoerner,TechnicalUniversityofDenmark, and Florin Spanachi,SAP Research,Germany) over high-level modeling (Egon B.. orger, University of Pisa, Italy) and software product line techniques (Don Batory,UniversityofTexasatAustin,USA)toevolvablesoftware(PeterSestoft, Royal Veterinary and Agricultural University of Denmark) and the evolution of service-oriented software architectures (Carlo Ghezzi, Politecnico di Milano, Italy) in particular for Web services (Boualem Benatallah, University of New SouthWales,Australia)andthecrucialproblemofhowtoreachsecurity insuch evolvingdistributedsystems(DieterGollmann,TechnicalUniversityHamburg- Harburg,Germany).In two seminars the theme of evolvable software was further developed by the presentationofnew techniques forsoftwaremanipulation with annotations in Java (Vincenzo Gervasi, University of Pisa) and for the code-bricks-based runtime composition of self-evolving programs (Antonio Cisternino, University ofPisa). For unforseeablepersonalcircumstances MichaelJackson(London)was - abletodeliverhislecturesasplanned.However,thisvolumecontainshisre?- tions on which directions software engineering should take to become a truly engineeringdiscipline. This book is not a proceedings volume, but a collection of research papers on themes treated in the school,written with the intent to produce a state-- the art compendium of recent advances in software engineering. However, the contributions re?ect the extensive discussions we had during the two weeks in Lipari. Allcontributions,writtenbetweenAugust2007andJanuary2008,havebeen reviewed,revisedandreviewedagainduringtheperiodFebruary-August2008. We thank the 21 reviewers for their considerable and very constructive work, althoughasusualtheyhavetoremainanonymous.Lastbutnotleastwethank theauthorsfortheircommitmenttothisvolume.

Activities performed in organizations are coordinated via communication between the people involved. The sentences used to communicate are naturally structured by subject, verb, and object. The subject describes the actor, the verb the action and the object what is affected by the action. Subject-oriented Business Process Management (S-BPM) as presented in this book is based on this simple structure which enables process-oriented thinking and process modeling. S-BPM puts the subject of a process at the center of attention and thus deals with business processes and their organizational environment from a new perspective, meeting organizational requirements in a much better way than traditional approaches. Subjects represent agents of an action in a process, which can be either technical or human (e.g. a thread in an IT system or a clerk). A process structures the actions of each subject and coordinates the required communication among the subjects. S-BPM provides a coherent procedural framework to model and analyze business processes: its focus is the cooperation of all stakeholders involved in the strategic, tactical, and operational issues, sharing their knowledge in a networked structure. The authors illustrate how each modeling activity through the whole development lifecycle can be supported through the use of appropriate software tools. The presentation style focuses on professionals in industry, and on students specializing in process management or organizational modeling. Each chapter begins with a summary of key findings and is full of examples, hints, and possible pitfalls. An interpreter model, a toolbox, and a glossary summarizing the main terms complete the book. The web site www.i2pm.net provides additional software tools and further material.

Activities performed in organizations are coordinated via communication between the people involved. The sentences used to communicate are naturally structured by subject, verb, and object. The subject describes the actor, the verb the action and the object what is affected by the action. Subject-oriented Business Process Management (S-BPM) as presented in this book is based on this simple structure which enables process-oriented thinking and process modeling. S-BPM puts the subject of a process at the center of attention and thus deals with business processes and their organizational environment from a new perspective, meeting organizational requirements in a much better way than traditional approaches. Subjects represent agents of an action in a process, which can be either technical or human (e.g. a thread in an IT system or a clerk). A process structures the actions of each subject and coordinates the required communication among the subjects. S-BPM provides a coherent procedural framework to model and analyze business processes: its focus is the cooperation of all stakeholders involved in the strategic, tactical, and operational issues, sharing their knowledge in a networked structure. The authors illustrate how each modeling activity through the whole development lifecycle can be supported through the use of appropriate software tools. The presentation style focuses on professionals in industry, and on students specializing in process management or organizational modeling. Each chapter begins with a summary of key findings and is full of examples, hints, and possible pitfalls. An interpreter model, a toolbox, and a glossary summarizing the main terms complete the book. The web site www.i2pm.net provides additional software tools and further material.

Quelli che s'innamoran di pratica senza scienzia sono come 'l nocchieri ch'entra in navilio sanza timone o bussola, 1 che mai ha certezza dove si vada. - Leonardo da Vinci Ich habe oft bemerkt, dass wir uns durch allzuvieles Symbolisieren 2 die Sprache fu ..r die Wirklichkeit untu ..chtig machen. - Christian Morgenstern This is the place to express our thanks. First of all we thank all those who over the years have actively contributed to shaping the novel software design and analysis method explained in this book. They are too numerous to be mentioned here. They all appear in some way or the other on the following pages, in particular in the bibliographical and historical Chap. 9 which can be read independently of the book. We then thank those who have helped with detailed critical comments on the draft chapters to shape the way our arguments are presented in this book: M. B.. orger (Diron Mu ..nster), I. Craggs (IBMHursley),G. DelCastillo(SiemensMunc .. hen),U. Gl. asser(SimonFraser University, Vancouver,Canada),J. Huggins(Kettering University,Michigan, USA), B. Koblinger (IBM Heidelberg), P. Pa ..ppinghaus (Siemens Munc .. hen), A.Preller (Universit' e de Montpellier, France), M. -L. Potet (INP de Gre- ble, France),W. Reisig (Humboldt-Universit. at zu Berlin, Germany),H. Rust (Universit. at Cottbus, Germany), G. Schellhorn (Universit. at Augsburg, G- many), B. Thalheim (Universit. at Cottbus, Germany) and a dozen student generationsat Universita 'di Pisa. We thankM. Barmet(ETH Zur .. ich)for her solutions of the exercises in Chap. 8. We also thank L.

This book grew out of material which was taught at the International Summer School on Architecture Design and Validation Methods, held June 23-July 5, 1997, on the Island of Lipari and directed to graduate students and young researchers. Since then the course notes have been completely elaborated and extended and additional chapters have been added so that this book offers a comprehensive presentation of the state of the art which leads the reader to the forefront of the current research in the area. The chapters, each of which was written by a group of eminent special­ ists in the field, are self-contained and can be read independently of each other. They cover the wide range of theoretical and practical methods which currently used for the specification, design, validation and verification of are hardware/software architectures. Synthesis methods are the subject of the first three chapters. The chapter on Modeling and Synthesis of Behavior, Control and Data Flow focusses on techniques above the register-transfer level. The chapter on Cell-Based Logic Optimizations concentrates on methods that interface logic design with phys­ ical design, in particular on techniques for cell-library binding, the back-end of logic synthesis. The chapter on A Design Flow for Performance Planning presents new paradigms for iteration-free synthesis where global wire plans for meeting timing constraints already appear at the conceptual design stage, even before fixing the functionality of the blocks in the plan.

The origin of this book goes back to the Dagstuhl seminar on Logic for System Engineering, organized during the first week of March 1997 by S. Jiihnichen, J. Loeckx, and M. Wirsing. During that seminar, after Egon Borger's talk on How to Use Abstract State Machines in Software Engineering, Wolfram Schulte, at the time a research assistant at the University of Ulm, Germany, questioned whether ASMs provide anything special as a scientifically well­ founded and rigorous yet simple and industrially viable framework for high­ level design and analysis of complex systems, and for natural refinements of models to executable code. Wolfram Schulte argued, referring to his work with K. Achatz on A Formal Object-Oriented Method Inspired by Fusion and Object-Z [1], that with current techniques of functional programming and of axiomatic specification, one can achieve the same result. An intensive and long debate arose from this discussion. At the end of the week, it led Egon Borger to propose a collaboration on a real-life specification project of Wolfram Schulte's choice, as a comparative field test of purely functional­ declarative methods and of their enhancement within an integrated abstract state-based operational (ASM) approach. After some hesitation, in May 1997 Wolfram Schulte accepted the offer and chose as the theme a high-level specification of Java and of the Java Virtual Machine.