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23
Multivalued Possibilities Mappings
 Stepwise Refinement of Distributed Systems, volume LNCS 430
, 1989
"... Abstraction mappings are one of the major tools used to construct correctness proofs for concurrent algorithms. Several examples axe given of situations in which it is useful to allow the abstraction mappings to be multivalued, The examples involve algorithm optimization, algorithm distribution, and ..."
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Cited by 13 (2 self)
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Abstraction mappings are one of the major tools used to construct correctness proofs for concurrent algorithms. Several examples axe given of situations in which it is useful to allow the abstraction mappings to be multivalued, The examples involve algorithm optimization, algorithm distribution, and proofs of time bounds.
Using Simulation Techniques to Prove Timing Properties
, 1995
"... This thesis presents a methodology based on simulations and invariants for proving timing properties of realtime, distributed systems. This methodology is used to prove tight time bounds for two systems, a leader election protocol for a ring of processes, and Fischer's timingbased mutual excl ..."
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Cited by 12 (1 self)
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This thesis presents a methodology based on simulations and invariants for proving timing properties of realtime, distributed systems. This methodology is used to prove tight time bounds for two systems, a leader election protocol for a ring of processes, and Fischer's timingbased mutual exclusion algorithm. A framework for verifying these proofs using the Larch tools is also developed, and the proof for Fischer's algorithm is checked within this framework. Many formal methods have been developed for proving the correctness of untimed distributed systems. However, realtime systems often have subtle timing dependencies that are difficult to analyze and reason about. Furthermore, for many realtime systems, correctness is insufficient; it is important to satisfy certain performance requirements. It is necessary, therefore, to extend the formal models and techniques to the timed setting. We use a timed automaton model, together with simulations which establish that one automaton impl...
Timeconstrained Reactive Automata  A Novel Development Methodology for Embedded Realtime Systems
, 1991
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A Stepwise Refinement Heuristic for Protocol Construction
 ACM Transactions on Programming Languages and Systems
, 1992
"... A stepwise refinement heuristic to construct distributed systems is presented The heuristic is based on a conditional refinement relation between system specifications, and a “Marking. ” It is applied to construct four sliding window protocols that provide reliable data transfer over unreliable comm ..."
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Cited by 10 (2 self)
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A stepwise refinement heuristic to construct distributed systems is presented The heuristic is based on a conditional refinement relation between system specifications, and a “Marking. ” It is applied to construct four sliding window protocols that provide reliable data transfer over unreliable communication channels. The protocols use moduloN sequence numbers. The first protocol is for channels that can only lose messages in transit. By refining this protocol, we obtain three protocols for channels that can lose, reorder, and duplicate messages in transit. The protocols herein are less restrictive and easier to implement than sliding window protocols previously studied in the protocol verification literature.
Compositional Inductive Verification of Duration Properties of RealTime Systems
 In Proc. of PROCOMET’98
, 1997
"... This paper proposes a method for formal realtime systems development. At high level a system is modelled as a conventional dynamical system with states that are functions of time represented by nonnegative real numbers, while the implementation and refinement at low level are described in terms of ..."
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Cited by 4 (3 self)
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This paper proposes a method for formal realtime systems development. At high level a system is modelled as a conventional dynamical system with states that are functions of time represented by nonnegative real numbers, while the implementation and refinement at low level are described in terms of timed transition systems (TTS). Therefore, The system requirements and high level design decisions are time interval properties, and are thus specified and reasoned about in the Duration Calculus (DC), and the properties of the implementation at low level are specified and verified compositionally and inductively in timed linear temporal logic (TLTL). A link from implementation properties to the requirement and design properties is given by interpreting a DC formula in a model of the executions of a TTS and then providing rules for lifting TLTL properties proved for a TTS to DC. The method is illustrated by the Gas Burner case study. Keywords: Realtime Systems, Duration Calculus, Timed Tran...
Formal Methods For The ReEngineering of Computing Systems
 In Proceedings of The 21st IEEE International Conference on Computer Software and Application (COMPSAC'97
, 1997
"... We present a short review of formal methods and their use in the reengineering of computing systems. The paper considers five classes of formal notations and theories, namely state/modelbased, logicbased, algebraicbased, process algebra and netbased formalisms together with combined formalisms ..."
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Cited by 3 (1 self)
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We present a short review of formal methods and their use in the reengineering of computing systems. The paper considers five classes of formal notations and theories, namely state/modelbased, logicbased, algebraicbased, process algebra and netbased formalisms together with combined formalisms. Keywords : formal methods, reengineering, wide spectrum language, realtime systems, refinement, reverse engineering, logic. Contents 1 INTRODUCTION 2 2 CLASSIFICATION OF FORMAL METHODS 4 2.1 Modelbased Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Logicbased Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 Algebraic Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.4 Process Algebra Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.5 NetBased Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 CRITERIA AND RESULTS 17 4 DISCUSS...
TimingBased, Distributed Computation: Algorithms and Impossibility Results A thesis presented by
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A Model Parametric RealTime Logic
, 1992
"... TRIO is a formal notation for logicbased specification of realtime systems. In this paper, we briefly summarise the language and its straightforward modeltheoretic semantics. Then we discuss the need for assigning a consistent meaning to TRIO specifications, with reference to a variety of unde ..."
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TRIO is a formal notation for logicbased specification of realtime systems. In this paper, we briefly summarise the language and its straightforward modeltheoretic semantics. Then we discuss the need for assigning a consistent meaning to TRIO specifications, with reference to a variety of underlying time structures such as infinite time structures (both dense and discrete) and finite time structures. The main motivation is the ability to validate formal specifications. We present a solution to this problem, which gives a new, modelparametric semantics to the language. We define an algorithm for constructively verifying the satisfiability of formulas in the decidable cases, and we characterize several important temporal properties of specifications.