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15
Modal and Temporal Logics for Processes
, 1996
"... this paper have been presented at the 4th European Summer School in Logic, Language and Information, University of Essex, 1992; at the Tempus Summer School for Algebraic and Categorical Methods in Computer Science, Masaryk University, Brno, 1993; and the Summer School in Logic Methods in Concurrency ..."
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Cited by 71 (2 self)
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this paper have been presented at the 4th European Summer School in Logic, Language and Information, University of Essex, 1992; at the Tempus Summer School for Algebraic and Categorical Methods in Computer Science, Masaryk University, Brno, 1993; and the Summer School in Logic Methods in Concurrency, Aarhus University, 1993. I would like to thank the organisers and the participants of these summer schools, and of the Banff higher order workshop. I would also like to thank Julian Bradfield for use of his Tex tree constructor for building derivation trees and Carron Kirkwood, Faron Moller, Perdita Stevens and David Walker for comments on earlier drafts.
Actions Speak Louder than Words: Proving Bisimilarity for ContextFree Processes
, 1991
"... Baeten, Bergstra, and Klop (and later Caucal) have proved the remarkable result that bisimulation equivalence is decidable for irredundant contextfree grammars. In this paper we provide a much simpler and much more direct proof of this result using a tableau decision method involving goaldirec ..."
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Cited by 45 (9 self)
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Baeten, Bergstra, and Klop (and later Caucal) have proved the remarkable result that bisimulation equivalence is decidable for irredundant contextfree grammars. In this paper we provide a much simpler and much more direct proof of this result using a tableau decision method involving goaldirected rules. The decision procedure also provides the essential part of the bisimulation relation between two processes which underlies their equivalence. We also show how to obtain a sound and complete sequentbased equational theory for such processes from the tableau system and how one can extract what Caucal calls a fundamental relation from a successful tableau.
Deciding BisimulationLike Equivalences with FiniteState Processes
, 1999
"... We show that characteristic formulae for nitestate systems up to bisimulationlike equivalences (e.g., strong and weak bisimilarity) can be given in the simple branchingtime temporal logic EF. Since EF is a very weak fragment of the modal µcalculus, model checking with EF is decidable for many mo ..."
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Cited by 41 (14 self)
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We show that characteristic formulae for nitestate systems up to bisimulationlike equivalences (e.g., strong and weak bisimilarity) can be given in the simple branchingtime temporal logic EF. Since EF is a very weak fragment of the modal µcalculus, model checking with EF is decidable for many more classes of infinitestate systems. This yields a general method for proving decidability of bisimulationlike equivalences between infinitestate processes and finitestate ones. We apply this method to the class of PAD processes, which strictly subsumes PA and pushdown (PDA) processes, showing that a large class of bisimulationlike equivalences (including, e.g., strong and weak bisimilarity) is decidable between PAD and finitestate processes. On the other hand, we also demonstrate that no `reasonable' bisimulationlike equivalence is decidable between stateextended PA processes and finitestate ones. Furthermore, weak bisimilarity with finitestate processes is shown to be undecidable even for state...
Undecidable Equivalences for Basic Parallel Processes
 13th Conference on Foundations of Software Technology and Theoretical Computer Science
, 1993
"... . Recent results show that strong bisimilarity is decidable for the class of Basic Parallel Processes (BPP), which corresponds to the subset of CCS definable using recursion, action prefixing, nondeterminism and the full merge operator. In this paper we examine all other equivalences in the linear/b ..."
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Cited by 25 (2 self)
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. Recent results show that strong bisimilarity is decidable for the class of Basic Parallel Processes (BPP), which corresponds to the subset of CCS definable using recursion, action prefixing, nondeterminism and the full merge operator. In this paper we examine all other equivalences in the linear/branching time hierarchy [12] and show that none of them are decidable for BPP. 1 Introduction Much attention has been devoted to the study of process calculi and in particular to behavioural semantics for these calculi. In order to capture the behavioural aspects of processes, a variety of equivalences have been proposed. Various criteria exist for comparing the merits and deficiencies of these equivalences. A systematic approach consists of classifying the equivalences according to their coarseness. For this purpose van Glabbeek proposed the linear/branching time spectrum which is illustrated in Figure 1 [12]. The least discriminating equivalences are at the bottom of the diagram. Arrows i...
Regularity is Decidable for Normed PA Processes in Polynomial Time
, 1996
"... A process # is regular if it is bisimilar to a process # # with finitely many states. We prove that regularity of normed PA processes is decidable and we present a practically usable polynomialtime algorithm. Moreover, if the tested normed PA process # is regular then the process # # can be ..."
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Cited by 18 (3 self)
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A process # is regular if it is bisimilar to a process # # with finitely many states. We prove that regularity of normed PA processes is decidable and we present a practically usable polynomialtime algorithm. Moreover, if the tested normed PA process # is regular then the process # # can be e#ectively constructed. It implies decidability of bisimulation equivalence for any pair of processes such that one process of this pair is a normed PA process and the other process has finitely many states.
Decidability Issues for InfiniteState Processes  a Survey
, 1996
"... this paper we survey recent developments and current trends within a new field of study within process algebra, namely that of decidability issues for processes with infinite transition graphs. ..."
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Cited by 8 (0 self)
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this paper we survey recent developments and current trends within a new field of study within process algebra, namely that of decidability issues for processes with infinite transition graphs.
Simulation Preorder on Simple Process Algebras
, 1999
"... We consider the problem of simulation preorder/equivalence between infinitestate processes and finitestate ones. We prove that simulation preorder (in both directions) and simulation equivalence are intractable between all major classes of infinitestate systems and finitestate ones. This resul ..."
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Cited by 8 (3 self)
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We consider the problem of simulation preorder/equivalence between infinitestate processes and finitestate ones. We prove that simulation preorder (in both directions) and simulation equivalence are intractable between all major classes of infinitestate systems and finitestate ones. This result is obtained by showing that the problem whether a BPA (or BPP) process simulates a finitestate one is PSPACEhard, and the other direction is coNPhard; consequently, simulation equivalence between BPA (or BPP) and finitestate processes is also coNPhard. The decidability border for the mentioned problem is also established. Simulation preorder (in both directions) and simulation equivalence are shown to be decidable in EXPTIME between pushdown processes and finitestate ones. On the other hand, simulation preorder is undecidable between PA and finitestate processes in both directions. The obtained results also hold for those PA and finitestate processes which are determini...
Weak bisimilarity with infinitestate systems can be decided in polynomial time
 In Proc. of CONCUR'99, volume 1664 of LNCS
, 1999
"... Abstract. We prove that weak bisimilarity is decidable in polynomial time between BPA and finitestate processes, and between normed BPP and finitestate processes. To the best of our knowledge, these are the first polynomial algorithms for weak bisimilarity with infinitestate systems. 1 ..."
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Cited by 7 (4 self)
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Abstract. We prove that weak bisimilarity is decidable in polynomial time between BPA and finitestate processes, and between normed BPP and finitestate processes. To the best of our knowledge, these are the first polynomial algorithms for weak bisimilarity with infinitestate systems. 1
Unfold/Fold Transformations of Concurrent Processes
 Proc. 8th Int'l Symp. on Programming Languages: Implementations, Logics and Programs
, 1996
"... Program transformation is a technique for obtaining, starting from a program P, a semantically equivalent one, which is "better" than P with respect to a particular goal. Traditionally, the main goal of program transformation was obtaining more efficient programs, but, in general, this technique can ..."
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Cited by 4 (0 self)
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Program transformation is a technique for obtaining, starting from a program P, a semantically equivalent one, which is "better" than P with respect to a particular goal. Traditionally, the main goal of program transformation was obtaining more efficient programs, but, in general, this technique can be used to produce programs written in a syntactic form satisfying some properties. Program transformation techniques have been extensively studied in the framework of functional and logic languages, where they were applied mainly to obtain more efficient and readable programs. All these works are based on the Unfold/Fold program transformation method developed by Burstall and Darlington in the context of their recursive equational language. The use of Unfold /Fold based transformations for concurrent languages is a relevant issue that has not yet received an adequate attention. In fact the existing proposals of transformations of concurrent programs are not based on a general Unfold/Fold transformation theory. The aim of this paper is to define such a theory for the concurrent calculus CCS and to prove it correct. 1
Bisimilarity of Processes with Finitestate Systems
 ELECTRONIC NOTES IN THEORETICAL COMPUTER SCIENCE
, 1997
"... We describe a general method for deciding bisimilarity for pairs of processes where one process has finitely many states. We apply this method to pushdown processes and to PA processes. We also demonstrate that the mentioned problem is undecidable for `stateextended' PA processes. ..."
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Cited by 4 (2 self)
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We describe a general method for deciding bisimilarity for pairs of processes where one process has finitely many states. We apply this method to pushdown processes and to PA processes. We also demonstrate that the mentioned problem is undecidable for `stateextended' PA processes.