Results 1  10
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14
Decoding Choice Encodings
, 1999
"... We study two encodings of the asynchronous #calculus with inputguarded choice into its choicefree fragment. One encoding is divergencefree, but refines the atomic commitment of choice into gradual commitment. The other preserves atomicity, but introduces divergence. The divergent encoding is ..."
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Cited by 97 (5 self)
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We study two encodings of the asynchronous #calculus with inputguarded choice into its choicefree fragment. One encoding is divergencefree, but refines the atomic commitment of choice into gradual commitment. The other preserves atomicity, but introduces divergence. The divergent encoding is fully abstract with respect to weak bisimulation, but the more natural divergencefree encoding is not. Instead, we show that it is fully abstract with respect to coupled simulation, a slightly coarserbut still coinductively definedequivalence that does not enforce bisimilarity of internal branching decisions. The correctness proofs for the two choice encodings introduce a novel proof technique exploiting the properties of explicit decodings from translations to source terms.
On Asynchrony in NamePassing Calculi
 In
, 1998
"... The asynchronous picalculus is considered the basis of experimental programming languages (or proposal of programming languages) like Pict, Join, and Blue calculus. However, at a closer inspection, these languages are based on an even simpler calculus, called Local (L), where: (a) only the output c ..."
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Cited by 88 (14 self)
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The asynchronous picalculus is considered the basis of experimental programming languages (or proposal of programming languages) like Pict, Join, and Blue calculus. However, at a closer inspection, these languages are based on an even simpler calculus, called Local (L), where: (a) only the output capability of names may be transmitted; (b) there is no matching or similar constructs for testing equality between names. We study the basic operational and algebraic theory of Lpi. We focus on bisimulationbased behavioural equivalences, precisely on barbed congruence. We prove two coinductive characterisations of barbed congruence in Lpi, and some basic algebraic laws. We then show applications of this theory, including: the derivability of delayed input; the correctness of an optimisation of the encoding of callbyname lambdacalculus; the validity of some laws for Join.
Types for Dyadic Interaction
, 1993
"... We formulate a typed formalism for concurrency where types denote freely composable structure of dyadic interaction in the symmetric scheme. The resulting calculus is a typed reconstruction of name passing process calculi. Systems with both the explicit and implicit typing disciplines, where types f ..."
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Cited by 83 (10 self)
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We formulate a typed formalism for concurrency where types denote freely composable structure of dyadic interaction in the symmetric scheme. The resulting calculus is a typed reconstruction of name passing process calculi. Systems with both the explicit and implicit typing disciplines, where types form a simple hierarchy of types, are presented, which are proved to be in accordance with each other. A typed variant of bisimilarity is formulated and it is shown that typed fiequality has a clean embedding in the bisimilarity. Name reference structure induced by the simple hierarchy of types is studied, which fully characterises the typable terms in the set of untyped terms. It turns out that the name reference structure results in the deadlockfree property for a subset of terms with a certain regular structure, showing behavioural significance of the simple type discipline. 1 Introduction This is a preliminary study of types for concurrency. Types here denote freely composable structur...
Combinatory Representation of Mobile Processes
 In Proceedings of POPL '94
, 1994
"... A possible analogue of theory of combinators in the setting of concurrent processes is formulated. The new combinators are derived from the analysis of the operation called asynchronous name passing, just as the analysis of logical substitution gave rise to the sequential combinators. A system with ..."
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Cited by 18 (2 self)
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A possible analogue of theory of combinators in the setting of concurrent processes is formulated. The new combinators are derived from the analysis of the operation called asynchronous name passing, just as the analysis of logical substitution gave rise to the sequential combinators. A system with seven atoms and fixed interaction rules, but with no notion of prefixing, is introduced, and is shown to be capable of representing input and output prefixes over arbitrary terms in a behaviourally correct way, just as SKcombinators are closed under functional abstraction without having it as a proper syntactic construct. The basic equational correspondence between concurrent combinators and a system of asynchronous mobile processes, as well as the embedding of the finite part of ßcalculus in concurrent combinators, is proved. These results will hopefully serve as a cornerstone for further investigation of the theoretical as well as pragmatic possibilities of the presented construction. 1 ...
Basic Theory of Reduction Congruence for Two Timed Asynchronous πCalculi
 IN PROC. CONCUR’04
, 2004
"... We study reduction congruence, a popular notion of process equality, for the asynchronous πcalculus with timers, and derive several alternative characterisations, one of them being a labelled asynchronous bisimilarity. These results are adapted to an asynchronous πcalculus with timers, locatio ..."
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Cited by 18 (2 self)
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We study reduction congruence, a popular notion of process equality, for the asynchronous πcalculus with timers, and derive several alternative characterisations, one of them being a labelled asynchronous bisimilarity. These results are adapted to an asynchronous πcalculus with timers, locations and message failure. In addition we investigate the problem of how to distribute valuepassing processes in a semanticspreserving way.
Asynchronous process calculi: the firstorder and higherorder paradigms (Tutorial)
, 1999
"... We compare the firstorder and the higherorder... ..."
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Cited by 13 (0 self)
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We compare the firstorder and the higherorder...
Regional Analysis and a $\pi$Calculus With Groups
, 2000
"... this article that directly depends on the locality restriction imposed on the calculus. ..."
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Cited by 12 (0 self)
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this article that directly depends on the locality restriction imposed on the calculus.
On Equators in Asynchronous Namepassing Calculi without Matching (Extended Abstract)
, 1999
"... We give a labeled characterization of barbed congruence in asynchronous calculus, which, unlike previous characterizations, does not use the matching construct. In absence of matching the observer cannot directly distinguish two names. In asynchronous calculus the fact that two names are indisting ..."
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Cited by 7 (0 self)
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We give a labeled characterization of barbed congruence in asynchronous calculus, which, unlike previous characterizations, does not use the matching construct. In absence of matching the observer cannot directly distinguish two names. In asynchronous calculus the fact that two names are indistinguishable can be modeled by means of Honda and Yoshida's notion of equator. Our labeled characterization is based on such a notion. As an application of our theory we provide a fully abstract encoding w.r.t. barbed congruence of external mobility (communication of free names) in terms of internal mobility (communication of private names).
Process Semantics of Graph Reduction
 Proc. CONCUR '95, volume 962 of Lecture Notes in Computer Science
, 1995
"... This paper introduces an operational semantics for callbyneed reduction in terms of Milner's ßcalculus. The functional programming interest lies in the use of ßcalculus as an abstract yet realistic target language. The practical value of the encoding is demonstrated with an outline for a paralle ..."
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Cited by 6 (1 self)
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This paper introduces an operational semantics for callbyneed reduction in terms of Milner's ßcalculus. The functional programming interest lies in the use of ßcalculus as an abstract yet realistic target language. The practical value of the encoding is demonstrated with an outline for a parallel code generator. From a theoretical perspective, the ßcalculus representation of computational strategies with shared reductions is novel and solves a problem posed by Milner [13]. The compactness of the process calculus presentation makes it interesting as an alternative definition of callbyneed. Correctness of the encoding is proved with respect to the callbyneed calculus of Ariola et al. [3]. 1 Introduction Graph reduction of extended calculi has become a mature field of applied research. The efficiency of the implementations is due in great measure to a technique known as `sharing', whereby argument values are computed (at most) once and then memoized for future reference. Both...
Implicit Polymorphic Type System for the Blue Calculus
, 1997
"... The Blue Calculus is a direct extension of both the lambda and the pi calculi. In a preliminary work from Gérard Boudol, a simple type system was given that incorporates Curry's type inference for the lambdacalculus. In the present paper we study an implicit polymorphic type system, adapted from th ..."
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Cited by 4 (2 self)
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The Blue Calculus is a direct extension of both the lambda and the pi calculi. In a preliminary work from Gérard Boudol, a simple type system was given that incorporates Curry's type inference for the lambdacalculus. In the present paper we study an implicit polymorphic type system, adapted from the ML typing discipline. Our typing system enjoys subject reduction and principal type properties and we give results on the complexity for the type inference problem. These are interesting results for the blue calculus as a programming notation for higherorder concurrency.