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11
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...
Bisimulation for higherorder process calculi
 INFORMATION AND COMPUTATION
, 1996
"... A higherorder process calculus is a calculus for communicating systems which contains higherorder constructs like communication of terms. We analyse the notion of bisimulation in these calculi. We argue that both the standard definition of bisimulation (i.e., the one for CCS and related calculi), ..."
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Cited by 62 (5 self)
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A higherorder process calculus is a calculus for communicating systems which contains higherorder constructs like communication of terms. We analyse the notion of bisimulation in these calculi. We argue that both the standard definition of bisimulation (i.e., the one for CCS and related calculi), as well as higherorder bisimulation [E. Astesiano,
Branching bisimilarity is an equivalence indeed
 Inform. Process. Lett
, 1996
"... Communicated by P.M.B. Vitiyi This note presents a detailed proof of a result in the theory of concurrency semantics that is already considered folklore, namely that branching bisimilarity is an equivalence relation. The “simple proof ‘, which in the literature is always assumed to exist, is shown t ..."
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Cited by 33 (3 self)
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Communicated by P.M.B. Vitiyi This note presents a detailed proof of a result in the theory of concurrency semantics that is already considered folklore, namely that branching bisimilarity is an equivalence relation. The “simple proof ‘, which in the literature is always assumed to exist, is shown to be incorrect. The proof in this note is based on the notion of a semibranching bisimulation taken from (Van Glabbeek and Weijland, 1991). Branching bisimilarity can equivalently be defined in terms of semibranching bisimulations; the results suggest that such a definition is more intuitive than the original definition of Van Glabbeek and Weijland ( 1989).
Back and forth bisimulations
 Computer Science Report CS R9021, Centrum voor Wiskunde en Informatica
, 1990
"... This paper is concerned with bisimulation relations which do not only require related agents to simulate each others behavior in the direction of the arrows, but also to simulate each other when going back in history. First it is demonstrated that the back and forth variant of strong bisimulation le ..."
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Cited by 20 (2 self)
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This paper is concerned with bisimulation relations which do not only require related agents to simulate each others behavior in the direction of the arrows, but also to simulate each other when going back in history. First it is demonstrated that the back and forth variant of strong bisimulation leads to the same equivalence as the ordinary notion of strong bisimulation. Then it is shown that the back and forth variant of Milner's observation equivalence is different from (and finer than) observation equivalence. In fact we prove that it coincides with the branching bisimulation equivalence of Van Glabbeek & Weijland. Also the back and forth variants of branching, ~ and delay bisimulation lead to branching bisimulation equivalence. The notion of back and forth bisimulation moreover leads to characterizations of branching bisimulation in terms of abstraction homomorphisms and in terms of HencessyMilner logic with backward modalities. In our view these results support the claim that branching bisimulation is a natural and important notion. The notion of bisimulation relation has been introduced by PARK [18]. It leads to an equivalence on labelled transition systems which, in case image finiteness is assumed, coincides with the strong equivalence of ~IILNER [12]. The great importance and usefulness of bisimulalions
Inheritance of Behavior
 Journal of Logic and Algebraic Programming
, 1999
"... One of the key issues of objectoriented modeling and design is inheritance. It allows for the definition of subclasses that inherit features of some superclass. Inheritance is well defined for static properties of classes such as attributes and methods. However, there is no general agreement on the ..."
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Cited by 12 (1 self)
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One of the key issues of objectoriented modeling and design is inheritance. It allows for the definition of subclasses that inherit features of some superclass. Inheritance is well defined for static properties of classes such as attributes and methods. However, there is no general agreement on the meaning of inheritance when considering the dynamic behavior of objects, captured by their life cycles. This paper studies inheritance of behavior both in a simple processalgebraic setting and in a Petrinet framework. Process algebra is chosen, because it concentrates on behavior, while abstracting from the internal states of processes. The result of the algebraic study is a clear conceptual understanding of inheritance of behavior. It can be expressed in terms of blocking and hiding method calls. The results in the algebraic framework inspire the development of the concept of inheritance of behavior in the Petrinet framework. The Petrinet formalism allows for a graphical representation...
Formats of Ordered SOS Rules with Silent Actions
 Proceedings 7th Conference on Theory and Practice of Software Development (TAPSOFT'97), Lille, LNCS 1214
, 1997
"... We present a general and uniform method for defining structural operational semantics (SOS) of process algebra operators by traditional Plotkinstyle rules equipped with an ordering, the new feature which states the order of application of rules when deriving transitions of process terms. Our method ..."
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Cited by 7 (3 self)
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We present a general and uniform method for defining structural operational semantics (SOS) of process algebra operators by traditional Plotkinstyle rules equipped with an ordering, the new feature which states the order of application of rules when deriving transitions of process terms. Our method allows to represent negative premises and copying in the presence of silent actions. We identify a number of general formats of unordered and ordered rules with silent actions and show that divergence sensitive branching and weak bisimulation relations are preserved by all operators in the relevant formats. A comparison with the existing formats for branching and weak bisimulations shows that our formats are more general.
Ordered SOS Rules and Weak Bisimulation
 Theory and Formal Methods
, 1996
"... this paper we will only consider those formats of rules which treat silent actions as invisible; for example the formats in [8, 10, 11, 9, 12]. A number of important results were established for these formats. Firstly, certain weak equivalences were shown to be preserved by all process operators in ..."
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Cited by 4 (3 self)
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this paper we will only consider those formats of rules which treat silent actions as invisible; for example the formats in [8, 10, 11, 9, 12]. A number of important results were established for these formats. Firstly, certain weak equivalences were shown to be preserved by all process operators in these formats [10, 9, 12]. Secondly, (completed) trace congruences with respect to these formats were discovered [10, 11]. Thirdly, algorithms for generating complete axiomatisations of some weak equivalences were developed [13, 14, 15]. The main conceptual contribution of the paper is a new method for defining process operators, including the sequential composition and priority operators, by transition rules with no negative antecedents. Our method is based on a simple idea of ordering the transition rules for each operator. The behaviour of a process can then be determined by examining the rules of its main operator, starting with the rules highest in the ordering and then considering the rules lower in the ordering. As a result, a rule lower in the ordering can only be applied if none of the rules above it can. Intuitively, this has the effect of applying a rule with negative antecedents. A simple example is given to illustrate our method. Consider a priority operator `, which gives a a priority over b, defined by the following rules.
Symbolic abstractions of automata and their application to the supervisory control problem
, 1999
"... In this report, we describe the design of abstraction methods based on symbolic techniques: classical abstraction by state fusion has been considered. we present a general method to abstract automata on the basis of a state fusion criterion, derived from e.g. equivalence relations (such as bisimul ..."
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Cited by 4 (2 self)
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In this report, we describe the design of abstraction methods based on symbolic techniques: classical abstraction by state fusion has been considered. we present a general method to abstract automata on the basis of a state fusion criterion, derived from e.g. equivalence relations (such as bisimulation), partitions,... We also introduced other kinds of abstraction, falling into the category of abstraction by restriction: in particular, we studied the use of the controller synthesis methodology to achieve the restriction synthesis. The methods rely on symbolic representation of the labeled transition system, namely the Intensional Labeled Transition System (ILTS). It is a behavioral model for Discrete event systems based on polynomial approach, that has e ective applications for the analysis of Signal programs. We finally apply this methodology to solve the Supervisory Control Problem.
Ordered SOS Process Languages for Branching and Eager Bisimulations
 INFORMATION AND COMPUTATION
, 2002
"... We present a general and uniform method for defining structural operational semantics (SOS) of process operators by traditional Plotkinstyle transition rules equipped with orderings. This new feature allows one to control the order of application of rules when deriving transitions of process terms. ..."
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Cited by 2 (0 self)
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We present a general and uniform method for defining structural operational semantics (SOS) of process operators by traditional Plotkinstyle transition rules equipped with orderings. This new feature allows one to control the order of application of rules when deriving transitions of process terms. Our method is powerful enough to deal with rules with negative premises and copying. We show that rules with orderings, called ordered SOS rules, have the same expressive power as GSOS rules. We identify several classes of process languages with operators defined by rules with and without orderings in the setting with silent actions and divergence. We prove that branching bisimulation and eager bisimulation relations are preserved by all operators in process languages in the relevant classes.
On the observational theory of the CPScalculus ∗
"... We study the observational theory of Thielecke’s CPScalculus, a distillation of the target language of ContinuationPassing Style transforms. We define a labelled transition system for the CPScalculus from which we derive a (weak) labelled bisimilarity that completely characterises Morris ’ contex ..."
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Cited by 2 (0 self)
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We study the observational theory of Thielecke’s CPScalculus, a distillation of the target language of ContinuationPassing Style transforms. We define a labelled transition system for the CPScalculus from which we derive a (weak) labelled bisimilarity that completely characterises Morris ’ contextequivalence. We prove a context lemma showing that Morris ’ contextequivalence coincides with a simpler contextequivalence closed under a smaller class of contexts. Then we profit of the determinism of the CPScalculus to give a simpler labelled characterisation of Morris ’ equivalence, in the style of Abramsky’s applicative bisimilarity. We enhance our bisimulation proofmethods with upto bisimilarity and upto context proof techniques. We use our bisimulation proof techniques to investigate a few algebraic properties on diverging terms that cannot be proved using the original axiomatic semantics of the CPScalculus. Finally, we prove the full abstraction of Thielecke’s encoding of the CPScalculus into a fragment of Fournet and Gonthier’s Joincalculus with single pattern definitions. 1