Towards Verified Systems

As the complexity of embedded computer-controlled systems increases, the present industrial practice for their development gives cause for concern, especially for safety-critical applications where human lives are at stake. The use of software in such systems has increased enormously in the last decade. Formal methods, based on firm mathematical foundations, provide one means to help with reducing the risk of introducing errors during specification and development. There is currently much interest in both academic and industrial circles concerning the issues involved, but the techniques still need further investigation and promulgation to make their widespread use a reality. This book presents results of research into techniques to aid the formal verification of mixed hardware/software systems. Aspects of system specification and verification from requirements down to the underlying hardware are addressed, with particular regard to real-time issues. The work presented is largely based around the Occam programming language and Transputer microprocessor paradigm. The HOL theorem prover, based on higher order logic, has mainly been used in the application of machine-checked proofs. The book describes research work undertaken on the collaborative UK DTI/SERC-funded Information Engineering Dictorate Safemos project. The partners were Inmos Ltd., Cambridge SRI, the Oxford University Computing Laboratory and the University of Cambridge Computer Laboratory, who investigated the problems of formally verifying embedded systems. The most important results of the project are presented in the form of a series of interrelated chapters by project members and associated personnel. In addition, overviews of two other ventures with similar objectives are included as appendices. The material in this book is intended for computing science researchers and advanced industrial practitioners interested in the application of formal methods to real-time safety-critical systems at all levels of abstraction from requirements to hardware. In addition, material of a more general nature is presented, which may be of interest to managers in charge of projects applying formal methods, especially for safety-critical-systems, and others who are considering their use.

This book investigates the design of compilers for procedural languages, based on the algebraic laws which these languages satisfy. The particular strategy adopted is to reduce an arbitrary source program to a general normal form, capable of representing an arbitrary target machine. This is achieved by a series of normal form reduction theorems which are proved algebraically from the more basic laws. The normal form and the related reduction theorems can then be instantiated to design compilers for distinct target machines. This constitutes the main novelty of the author's approach to compilation, together with the fact that the entire process is formalised within a single and uniform semantic framework of a procedural language and its algberaic laws. Furthermore, by mechanising the approach using the OBJ3 term rewriting system it is shown that a prototype compiler is developed as a byproduct of its own proof of correctness. Contents:IntroductionBackgroundThe Reasoning LanguageA Simple CompilerProcedures, Recursion and ParametersMachine SupportConclusions Readership: Computer scientists. keywords:Compiler Design;Compiler Correctness;Compilation;Algebraic Laws;Algebraic Transformations;Algebraic Semantics;Refinement Algebra;Refinement Laws;Term Rewriting;OBJ3

This book constitutes the refereed proceedings of the 5th International Conference on Formal Engineering Methods, ICFEM 2003, held in Singapore in November 2003. The 34 revised full papers presented together with 3 invited contributions were carefully reviewed and selected from 91 submissions. The papers are organized in topical sections on testing and validation, state diagrams, PVS/HOL, refinement, hybrid systems, Z/Object-Z, Petri nets, timed automata, system modelling and checking, and semantics and synthesis.

The two-volume set LNCS 8802 and LNCS 8803 constitutes the refereed proceedings of the 6th International Symposium on Leveraging Applications of Formal Methods, Verification and Validation, ISoLA 2014, held in Imperial, Corfu, Greece, in October 2014. The total of 67 full papers was carefully reviewed and selected for inclusion in the proceedings. Featuring a track introduction to each section, the papers are organized in topical sections named: evolving critical systems; rigorous engineering of autonomic ensembles; automata learning; formal methods and analysis in software product line engineering; model-based code generators and compilers; engineering virtualized systems; statistical model checking; risk-based testing; medical cyber-physical systems; scientific workflows; evaluation and reproducibility of program analysis; processes and data integration in the networked healthcare; semantic heterogeneity in the formal development of complex systems. In addition, part I contains a tutorial on automata learning in practice; as well as the preliminary manifesto to the LNCS Transactions on the Foundations for Mastering Change with several position papers. Part II contains information on the industrial track and the doctoral symposium and poster session.

Given the growing size and heterogeneity of Systems on Chip (SOC), the design process from initial specification to chip fabrication has become increasingly complex. This growing complexity provides incentive for designers to use high-level languages such as C, SystemC, and SystemVerilog for system-level design. While a major goal of these high-level languages is to enable verification at a higher level of abstraction, allowing early exploration of system-level designs, the focus so far for validation purposes has been on traditional testing techniques such as random testing and scenario-based testing. This book focuses on high-level verification, presenting a design methodology that relies upon advances in synthesis techniques as well as on incremental refinement of the design process. These refinements can be done manually or through elaboration tools. This book discusses verification of specific properties in designs written using high-level languages, as well as checking that the refined implementations are equivalent to their high-level specifications. The novelty of each of these techniques is that they use a combination of formal techniques to do scalable verification of system designs completely automatically. The verification techniques presented in this book include methods for verifying properties of high-level designs and methods for verifying that the translation from high-level design to a low-level Register Transfer Language (RTL) design preserves semantics. Used together, these techniques guarantee that properties verified in the high-level design are preserved through the translation to low-level RTL.

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.

The increasing use of computers for real-time control on board spacecrafts has brought with it a greater emphasis on the development methodology used for such systems. By their nature, spacecraft control computers have to operate unattended for long periods and because of the programmatics of space, systems are subject to a long development cycle. As a result, there are two distinct concerns, the first being that the development approach guarantees functional and timing correctness, the second being that problems, particularly those associated with timing, are considered as early as possible in the spacecraft development life cycle. The European Space Agency has, for a number of years, encouraged the development of software using HOOD. It was thus a natural next step to investigate the incorporation of time within the existing HOOD framework. This has proven to be very beneficial and this book describes the approach developed by the authors for handling Hard Real-Time applications. It describes both the background scheduling theory, provides practical examples of its application to real life problems, and demonstrates how it is used in the various phases of the development of Hard Real-Time systems.

Through expanded intelligence, the use of robotics has fundamentally transformed a variety of fields, including manufacturing, aerospace, medicine, social services, and agriculture. Continued research on robotic design is critical to solving various dynamic obstacles individuals, enterprises, and humanity at large face on a daily basis. Robotic Systems: Concepts, Methodologies, Tools, and Applications is a vital reference source that delves into the current issues, methodologies, and trends relating to advanced robotic technology in the modern world. Highlighting a range of topics such as mechatronics, cybernetics, and human-computer interaction, this multi-volume book is ideally designed for robotics engineers, mechanical engineers, robotics technicians, operators, software engineers, designers, programmers, industry professionals, researchers, students, academicians, and computer practitioners seeking current research on developing innovative ideas for intelligent and autonomous robotics systems.