The Temporal Logic Of Reactive And Concurrent Systems

Reactive systems are computing systems which are interactive, such as real-time systems, operating systems, concurrent systems, control systems, etc. They are among the most difficult computing systems to program. Temporal logic is a formal tool/language which yields excellent results in specifying reactive systems. This volume, the first of two, subtitled Specification, has a self-contained introduction to temporal logic and, more important, an introduction to the computational model for reactive programs, developed by Zohar Manna and Amir Pnueli of Stanford University and the Weizmann Institute of Science, Israel, respectively.

This book is about the verification of reactive systems. A reactive system is a system that maintains an ongoing interaction with its environment, as opposed to computing some final value on termination. The family of reactive systems includes many classes of programs whose correct and reliable construction is con sidered to be particularly challenging, including concurrent programs, embedded and process control programs, and operating systems. Typical examples of such systems are an air traffic control system, programs controlling mechanical devices such as a train, or perpetually ongoing processes such as a nuclear reactor. With the expanding use of computers in safety-critical areas, where failure is potentially disastrous, correctness is crucial. This has led to the introduction of formal verification techniques, which give both users and designers of software and hardware systems greater confidence that the systems they build meet the desired specifications. Framework The approach promoted in this book is based on the use of temporal logic for specifying properties of reactive systems, and develops an extensive verification methodology for proving that a system meets its temporal specification. Reactive programs must be specified in terms of their ongoing behavior, and temporal logic provides an expressive and natural language for specifying this behavior. Our framework for specifying and verifying temporal properties of reactive systems is based on the following four components: 1. A computational model to describe the behavior of reactive systems. The model adopted in this book is that of a Fair Transition System (FTS).

This book is about the verification of reactive systems. A reactive system is a system that maintains an ongoing interaction with its environment, as opposed to computing some final value on termination. The family of reactive systems includes many classes of programs whose correct and reliable construction is con sidered to be particularly challenging, including concurrent programs, embedded and process control programs, and operating systems. Typical examples of such systems are an air traffic control system, programs controlling mechanical devices such as a train, or perpetually ongoing processes such as a nuclear reactor. With the expanding use of computers in safety-critical areas, where failure is potentially disastrous, correctness is crucial. This has led to the introduction of formal verification techniques, which give both users and designers of software and hardware systems greater confidence that the systems they build meet the desired specifications. Framework The approach promoted in this book is based on the use of temporal logic for specifying properties of reactive systems, and develops an extensive verification methodology for proving that a system meets its temporal specification. Reactive programs must be specified in terms of their ongoing behavior, and temporal logic provides an expressive and natural language for specifying this behavior. Our framework for specifying and verifying temporal properties of reactive systems is based on the following four components: 1. A computational model to describe the behavior of reactive systems. The model adopted in this book is that of a Fair Transition System (FTS).

This book presents five tutorial-style lectures on various approaches to the problem of verifying distributed systems: three chapters concentrate on linear-time or branching-time temporal logics; one addresses process equivalence with an emphasis on infinite-state systems; and the final one presents a novel category-theoretic approach to verification. The various formalisms for expressing properties of concurrent systems, based on automata-theoretic techniques or structural properties, are studied in detail. Much attention is paid to the style of writing and complementary coverage of the relevant issues. Thus these lecture notes are ideally suited for advanced courses on logics for concurrent systems. Equally, they are indispensable reading for anyone researching the area of distributed computing.

This book constitutes the refereed proceedings of the 14th International Conference on Concurrency Theory, CONCUR 2003, held in Marseille, France in September 2003. The 29 revised full papers presented together with 4 invited papers were carefully reviewed and selected from 107 submissions. The papers are organized in topical sections on partial orders and asynchronous systems, process algebras, games, infinite systems, probabilistic automata, model checking, model checking and HMSC, security, mobility, compositional methods and real time, and probabilistic models.

Time is ubiquitous in information systems. Almost every enterprise faces the problem of its data becoming out of date. However, such data is often valu able, so it should be archived and some means to access it should be provided. Also, some data may be inherently historical, e.g., medical, cadastral, or ju dicial records. Temporal databases provide a uniform and systematic way of dealing with historical data. Many languages have been proposed for tem poral databases, among others temporal logic. Temporal logic combines ab stract, formal semantics with the amenability to efficient implementation. This chapter shows how temporal logic can be used in temporal database applica tions. Rather than presenting new results, we report on recent developments and survey the field in a systematic way using a unified formal framework [GHR94; Ch094]. The handbook [GHR94] is a comprehensive reference on mathematical foundations of temporal logic. In this chapter we study how temporal logic is used as a query and integrity constraint language. Consequently, model-theoretic notions, particularly for mula satisfaction, are of primary interest. Axiomatic systems and proof meth ods for temporal logic [GHR94] have found so far relatively few applications in the context of information systems. Moreover, one needs to bear in mind that for the standard linearly-ordered time domains temporal logic is not re cursively axiomatizable [GHR94]' so recursive axiomatizations are by necessity incomplete.