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20
The Linear TimeBranching Time Spectrum II  The semantics of sequential systems with silent moves
, 1993
"... ion Rule (KFAR) (Baeten, Bergstra & Klop [3]), expresses a global fairness assumption. It says that when possible a system will escape from any cycle of internal actions. Some form of KFAR is crucial for many protocal verifications with unreliable channels, and for that reason preorders and equivale ..."
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Cited by 290 (17 self)
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ion Rule (KFAR) (Baeten, Bergstra & Klop [3]), expresses a global fairness assumption. It says that when possible a system will escape from any cycle of internal actions. Some form of KFAR is crucial for many protocal verifications with unreliable channels, and for that reason preorders and equivalences that satisfy KFAR are of special interest. Must preorders and divergence sensitive ones cannot satisfy KFAR. In Bergstra, Klop & Olderog [7] it is shown that the combination of KFAR with failure semantics is inconsistent, but they formulate a weaker version of KFAR that is satisfied in failure maysemantics. Still the combination of KFAR \Gamma and the liveness requirement appears to require global testing, and is only satisfied in the semantics between contrasimulation (C) and stability respecting branching bisimulation (BB s ). These requirements would reduce the number of suitable preorders to 18. It is in general a good strategy to do your verifications using the finest preorde...
Modal Logic, Transition Systems and Processes
, 1994
"... Transition systems can be viewed either as process diagrams or as Kripke structures. The first perspective is that of process theory, the second that of modal logic. This paper shows how various formalisms of modal logic can be brought to bear on processes. Notions of bisimulation can not only be mo ..."
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Cited by 24 (3 self)
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Transition systems can be viewed either as process diagrams or as Kripke structures. The first perspective is that of process theory, the second that of modal logic. This paper shows how various formalisms of modal logic can be brought to bear on processes. Notions of bisimulation can not only be motivated by operations on transition systems, but they can also be suggested by investigations of modal formalisms. To show that the equational view of processes from process algebra is closely related to modal logic, we consider various ways of looking at the relation between the calculus of basic process algebra and propositional dynamic logic. More concretely, the paper contains preservation results for various bisimulation notions, a result on the expressive power of propositional dynamic logic, and a definition of bisimulation which is the proper notion of invariance for concurrent propositional dynamic logic. Keywords: modal logic, transition systems, bisimulation, process algebra 1 In...
Supervision patterns in discrete event systems diagnosis
 IN 8TH INTERNAT. WORKSHOP ON DISCRETE EVENT SYST
, 2006
"... In this paper, we are interested in the diagnosis of discrete event systems modeled by finite transition systems. We propose a model of supervision patterns general enough to capture past occurrences of particular trajectories of the system. Modeling the diagnosis objective by a supervision pattern ..."
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Cited by 22 (9 self)
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In this paper, we are interested in the diagnosis of discrete event systems modeled by finite transition systems. We propose a model of supervision patterns general enough to capture past occurrences of particular trajectories of the system. Modeling the diagnosis objective by a supervision pattern allows us to generalize the properties to be diagnosed and to render them independent of the description of the system. We first formally define the diagnosis problem in this context. We then derive techniques for the construction of a diagnoser and for the verification of the diagnosticability based on standard operations on transition systems. We show that these techniques are general enough to express and solve in a unified way a broad class of diagnosis problems found in the literature, e.g. diagnosing permanent faults, multiple faults, fault sequences and some problems of intermittent faults.
On Implementations and Semantics of a Concurrent Programming Language
 IN PROCEEDINGS OF CONCUR '97. LNCS 1243
, 1997
"... The concurrency theory literature contains many proposals for models of process algebras. We consider an example application of the πcalculus, the programming language Pict of Pierce and Turner, primarily in order to see how far it is possible to argue, from facts about the application, that some m ..."
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Cited by 19 (12 self)
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The concurrency theory literature contains many proposals for models of process algebras. We consider an example application of the πcalculus, the programming language Pict of Pierce and Turner, primarily in order to see how far it is possible to argue, from facts about the application, that some model is the most appropriate. We discuss informally the sense in which the semantics of Pict relates to the behaviour of actual implementations. Based on this we give an operational model of the interactions between a Pict implementation (considered as the abstract behaviour of a C program) and its environment (modelling an operating system and user). We then give a class of abstract machines and a definition of abstract machine correctness, using an adapted notion of testing, and prove that a sample abstract machine is indeed correct. We briefly discuss the standard of correctness appropriate for program transformations and the induced precongruence. Many of the semantic choices do indeed t...
Rooted branching bisimulation as a congruence
 Journal of Computer and System Sciences
, 2000
"... This article presents a congruence format, in structural operational semantics, for rooted branching bisimulation equivalence. The format imposes additional requirements on Groote’s ntyft format. It extends an earlier format by Bloom with standard notions such as recursion, iteration, predicates, an ..."
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Cited by 15 (6 self)
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This article presents a congruence format, in structural operational semantics, for rooted branching bisimulation equivalence. The format imposes additional requirements on Groote’s ntyft format. It extends an earlier format by Bloom with standard notions such as recursion, iteration, predicates, and negative premises. 1
SOS formats and metatheory: 20 years after
, 2007
"... In 1981 Structural Operational Semantics (SOS) was introduced as a systematic way to define operational semantics of programming languages by a set of rules of a certain shape [G.D. Plotkin, A structural approach to operational semantics, Technical ..."
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Cited by 12 (5 self)
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In 1981 Structural Operational Semantics (SOS) was introduced as a systematic way to define operational semantics of programming languages by a set of rules of a certain shape [G.D. Plotkin, A structural approach to operational semantics, Technical
Process Algebra with Recursive Operations
"... ing from just the two atomic actions in I def = fthrow; tailg, FIR b 1 yields I ((throw tail) throw head) = head: First, observe I (throw tail) = . Then, using (4), it easily follows that I ((throw tail) throw head) = head: This expresses that head eventually comes up, and thus ex ..."
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Cited by 10 (5 self)
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ing from just the two atomic actions in I def = fthrow; tailg, FIR b 1 yields I ((throw tail) throw head) = head: First, observe I (throw tail) = . Then, using (4), it easily follows that I ((throw tail) throw head) = head: This expresses that head eventually comes up, and thus excludes the infinite sequence of steps present in I ((throw tail) throw head). 7.2 Empty Process Let the symbol " denote the empty process, introduced as a unit for sequential composition by Koymans and Vrancken in [58] (see also [28, 74]). Obvious as " may be (being a unit for \Delta), its introduction is nontrivial because at the same time it must be a unit for k as well. In the design of BPA, PA, ACP and related axiom systems, it has proved useful to study versions of the theory, both with and without ". Just for this reason the star operation with its (original) defining equation as given by Kleene in [54] was introduced in process algebra. Taking y = " in x y, one obtains x ...
Process calculus based upon evaluation to committed form
 CONCUR'96: Concurrency Theory, Proc. 7th Int. Conf
, 1996
"... An approach to the semantics of CCSlikecommunicating processes is proposed that is based upon evaluation of processes to inputor outputcommitted form, with no explicit mention of silent actions. This leads to a coinductively de ned notion of evaluation bisimilaritya form of weak branchingtime e ..."
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Cited by 9 (1 self)
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An approach to the semantics of CCSlikecommunicating processes is proposed that is based upon evaluation of processes to inputor outputcommitted form, with no explicit mention of silent actions. This leads to a coinductively de ned notion of evaluation bisimilaritya form of weak branchingtime equivalence which is shown to be a congruence, even in the presence of summation. The relationship between this evaluationbased approach and the more traditional, labelled transition semantics is investigated. In particular, with some restriction on sums, CCS observation equivalence is characterised purely in terms of evaluation to committed form, and evaluation bisimilarity ischaracterised as a weak delay equivalence. These results are extended to the higher order case, where evaluation bisimilarity coincides with Sangiorgi's weak context bisimilarity. Anevaluationbased approach tocalculus and the relationship with Milner and Sangiorgi's reductionbased notion of barbed bisimulation are also examined. 1
Simulation and Equivalence between BPEL Process Models
 In Proc. of Intl. Conference DASD’05
, 2005
"... behavior Abstract behavior Enterpriselocal business process Enterpriselocal business process simulates is consistent to participates Proof Demand Crossorganizational business process Crossorganizational business process Globally specified abstract model Globally specified abst ..."
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Cited by 7 (2 self)
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behavior Abstract behavior Enterpriselocal business process Enterpriselocal business process simulates is consistent to participates Proof Demand Crossorganizational business process Crossorganizational business process Globally specified abstract model Globally specified abstract model Locally developed executable model Locally developed executable model Concrete behavior Concrete behavior Abstract behavior Abstract behavior Enterpriselocal business process Enterpriselocal business process simulates is consistent to participates Proof Demand Figure 1. Field of application sualizes the overall dependencies between the activities. Usually, it is refined in several steps during the development process. Finally, a very precise model, covering all necessary aspects, can be executed directly by help of a workflow engine. Hence, such a model is called executable model, whereas each model of a prior stage can be called "abstract " model in some sense. BPEL4WS can be used to express both: the abstract process model as well as the executable process model.
Bisimulation and FaultTolerance
 Department of Computer Science, University of Warwick
, 1995
"... Faulttolerance is the crucial property for a safetycritical system: to perform as specified in spite of failures in the operating environment. The purpose of this paper is to show how to establish such a property between a pair of concurrent systems: a highlevel specification and its faultaffect ..."
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Cited by 5 (2 self)
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Faulttolerance is the crucial property for a safetycritical system: to perform as specified in spite of failures in the operating environment. The purpose of this paper is to show how to establish such a property between a pair of concurrent systems: a highlevel specification and its faultaffected implementation. We model a fault by a set of transitions and define various extensions of the wellknown bisimulation equivalence to take such `faulty' transitions into account. Their logical characterization, in terms of the HennessyMilner logic, is presented. 1 Motivation Applications of the formal semantics have expanded over the years. Initially, it was mainly a concern for the designers of programming languages. The aim was to remove ambiguities in the design of compilers and so to make programs portable between different execution environments. More recently, formal semantics is used to justify the rules for proving correctness of programs and so to extend the language for describ...