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A symbolic semantics and bisimulation for Full LOTOS
 PROC. FORMAL TECHNIQUES FOR NETWORKED AND DISTRIBUTED SYSTEMS (FORTE XIV
, 2001
"... A symbolic semantics for Full LOTOS in terms of symbolic transition systems is defined; the semantics extends the standard one by giving meaning to symbolic, or (data) parameterised processes. Symbolic bisimulation is defined and illustrated with reference to examples. The approachtaken follows that ..."
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Cited by 32 (6 self)
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A symbolic semantics for Full LOTOS in terms of symbolic transition systems is defined; the semantics extends the standard one by giving meaning to symbolic, or (data) parameterised processes. Symbolic bisimulation is defined and illustrated with reference to examples. The approachtaken follows that applied to message passing CCS in [HL95], but differs in several significant aspects, taking account of the particular features of LOTOS: multiway synchronisation, value negotiation, selection predicates.
Symbolic Bisimulation for Full LOTOS
"... . A symbolic semantics for Full LOTOS in terms of symbolic transition systems is defined, following the approach taken for message passing CCS in [HL95a], altered to take account of the particular features of LOTOS (multiway synchronisation, value negotiation, selection predicates). Symbolic bisim ..."
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Cited by 9 (1 self)
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. A symbolic semantics for Full LOTOS in terms of symbolic transition systems is defined, following the approach taken for message passing CCS in [HL95a], altered to take account of the particular features of LOTOS (multiway synchronisation, value negotiation, selection predicates). Symbolic bisimulation over symbolic transition systems is defined, and symbolic bisimulation on ground behaviour expressions is shown to preserve the usual concrete (strong) bisimulation on the standard semantics. Finally, a modal logic based on symbolic transition systems is defined. All are illustrated with reference to examples. 1 Introduction Full LOTOS 4 is a message passing process algebra which combines some features of both CSP [Hoa85] and CCS [Mil89]. In order to accommodate multiway synchronisation, i.e. associative synchronisation between two or more processes, the standard semantics of LOTOS gives meaning only to processes with ground data; the semantics is in terms of structured labelled ...
Functionality decomposition by compositional correctness preserving transformation
 In Courcoubetis [13
"... We present an algorithm for the decomposition of processes in a process algebraic framework. Decomposition, or the refinement of process substructure, is an important design principle in the topdown development of concurrent systems. In the approach that we follow the decomposition is based on a gi ..."
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Cited by 7 (0 self)
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We present an algorithm for the decomposition of processes in a process algebraic framework. Decomposition, or the refinement of process substructure, is an important design principle in the topdown development of concurrent systems. In the approach that we follow the decomposition is based on a given partition of the actions of a system specification, such that for each partition class a subprocess must be created that realizes the actions in that class. In addition a suitable synchronization structure between the subprocesses must be present to ensure that the composite behaviour of the subprocesses is properly related to the behaviour of the original specification. We present our results for the processalgebraic specification language LOTOS and give a compositional algorithm for the transformation of the original specification into the required subprocesses. The resulting specification is observation congruent with the original, and, interestingly enough, the subprocesses inherit much of the structure of the original specification. The correctness preserving transformation has been implemented in a tool and has been used for the derivation of protocol specifications from formal descriptions of the desired service. This is possible as it can be shown that the required synchronization mechanisms between the subprocesses can be readily implemented over (reliable) asynchronous media.
Two Finite Specifications of a Queue
"... . Two finite specifications of a queue in ACP with abstraction are proven correct relative to a standard specification of a queue that employs an infinite data type for representing its contents. The proofs are given in the proof theory of ¯CRL, and the only `ø laws' used are xø = x and x(ø(y+z)+y) ..."
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Cited by 3 (0 self)
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. Two finite specifications of a queue in ACP with abstraction are proven correct relative to a standard specification of a queue that employs an infinite data type for representing its contents. The proofs are given in the proof theory of ¯CRL, and the only `ø laws' used are xø = x and x(ø(y+z)+y) = x(y+z). Therefore the proofs are adequate for both `branching bisimilarity' and `observation equivalence'. Additionally, it is shown that standard concurrency follows from RSP for a class of processes guardedly specifiable in ACP with abstraction. Key words & Phrases: process algebra, queue, guardedness. 1987 CR Categories: F.1.2, F.3.1, F3.2. 1 Introduction The purpose of this paper is to record correctness proofs of two finite specifications of a queue, introduced below. Both these specifications are already known for some time. However, of the first one no proof has been published yet (as far as we are aware), and only slight variants of the second one were proven correct. Further...
Verification of LOTOS Specifications using Term Rewriting Techniques
, 1994
"... Recently the use of formal methods in describing and analysing the behaviour of (computer) systems has become more common. This has resulted in the proliferation of a wide variety of different specification formalisms, together with analytical techniques and methodologies for specification developme ..."
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Cited by 2 (2 self)
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Recently the use of formal methods in describing and analysing the behaviour of (computer) systems has become more common. This has resulted in the proliferation of a wide variety of different specification formalisms, together with analytical techniques and methodologies for specification development. The particular specification formalism adopted for this study is LOTOS, an ISO standard formal description technique. Although there are many works dealing with how to write LOTOS specifications and how to develop a LOTOS specification from the initial abstract requirements specification to concrete implementation, relatively few works are concerned with the problems of expressing and proving the correctness of LOTOS specifications, i.e. verification. The main objective of this thesis is to address this shortfall by investigating the meaning of verification as it relates to concurrent systems in general, and in particular to those systems described using LOTOS. Further goals are to autom...
Formal Specification of Distributed Information Systems
, 1994
"... The design of distributed information systems tends to be complex and therefore errorprone. However, in the field of monolithic, i.e. nondistributed, information systems much has already been achieved, and by now, the principles of their design seem to be fairly wellunderstood. The past decade ha ..."
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The design of distributed information systems tends to be complex and therefore errorprone. However, in the field of monolithic, i.e. nondistributed, information systems much has already been achieved, and by now, the principles of their design seem to be fairly wellunderstood. The past decade has shown also remarkable progress in the development and application of formal methods for distributed systems, in particular in the area of protocol systems. For both application areas techniques and tools have been developed that have been accepted by considerable user communities. The project we describe here aims to study the combination of two formalisms that have been (largely) developed at the University of Twente, viz. the process algebraic protocol specification language LOTOS and the objectoriented database specification language TM. Its objective is to combine the strengths of both formalisms and their associated tools for the specification, verification, testing, and design of di...