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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,
Operational Theories of Improvement in Functional Languages (Extended Abstract)
 In Proceedings of the Fourth Glasgow Workshop on Functional Programming
, 1991
"... ) David Sands y Department of Computing, Imperial College 180 Queens Gate, London SW7 2BZ email: ds@uk.ac.ic.doc Abstract In this paper we address the technical foundations essential to the aim of providing a semantic basis for the formal treatment of relative efficiency in functional langu ..."
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Cited by 21 (9 self)
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) David Sands y Department of Computing, Imperial College 180 Queens Gate, London SW7 2BZ email: ds@uk.ac.ic.doc Abstract In this paper we address the technical foundations essential to the aim of providing a semantic basis for the formal treatment of relative efficiency in functional languages. For a general class of "functional" computation systems, we define a family of improvement preorderings which express, in a variety of ways, when one expression is more efficient than another. The main results of this paper build on Howe's study of equality in lazy computation systems, and are concerned with the question of when a given improvement relation is subject to the usual forms of (in)equational reasoning (so that, for example, we can improve an expression by improving any subexpression). For a general class of computation systems we establish conditions on the operators of the language which guarantee that an improvement relation is a precongruence. In addition, for...
Labelled Transition Logic: An Outline
, 1996
"... In the last ten years we have developed and experimented in a series of projects, including industry test cases, a method for the specification of reactive/concurrent/parallel/distributed systems both at the requirement and at the design level. We present here in outline its main technical features, ..."
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Cited by 12 (10 self)
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In the last ten years we have developed and experimented in a series of projects, including industry test cases, a method for the specification of reactive/concurrent/parallel/distributed systems both at the requirement and at the design level. We present here in outline its main technical features, providing pointers to appropriate references for more detailed presentations of single aspects, applications and documentation.
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
Modal Characterization of Weak Bisimulation for Higherorder Processes
 IN TAPSOFT97, VOLUME 1214 OF LNCS
, 1996
"... Context bisimulation [13, 1] has become an important notion of behavioral equivalence for higherorder processes. Weak forms of context bisimulation are particularly interesting, because of their high level of abstraction. We present a modal logic for this setting and provide a characterization of a ..."
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Cited by 6 (0 self)
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Context bisimulation [13, 1] has become an important notion of behavioral equivalence for higherorder processes. Weak forms of context bisimulation are particularly interesting, because of their high level of abstraction. We present a modal logic for this setting and provide a characterization of a variant of weak context bisimulation on secondorder processes. We show how the logic permits compositional reasoning. In comparison to previous work by Amadio and Dam [2] on the strong case, our modal logic supports derived operators through a complete duality and thus constitutes an appealing extension of HennessyMilner logic.
From πcalculus to HigherOrder πcalculus  and back
"... We compare the firstorder and the higherorder paradigms for the representation of mobility in process algebras. The prototypical calculus in the firstorder paradigm is the πcalculus. By generalising its sort mechanism we derive an !order extension, called HigherOrder πcalculus (HOπ). We gi ..."
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Cited by 6 (0 self)
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We compare the firstorder and the higherorder paradigms for the representation of mobility in process algebras. The prototypical calculus in the firstorder paradigm is the πcalculus. By generalising its sort mechanism we derive an !order extension, called HigherOrder πcalculus (HOπ). We give examples of its use, including the encoding of calculus. Surprisingly, we show that such an extension does not add expressiveness: Higherorder processes can be faithfully represented at first order. We conclude that the firstorder paradigm, which enjoys a simpler and more intuitive theory, should be taken as basic. Nevertheless, the study of the calculus encodings shows that a higherorder calculus can be very useful for reasoning at a more abstract level.
A Hierarchy of SOS Rule Formats
, 2005
"... 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 [62]. Subsequently, the format of SOS rules became the object of study. Using socalled Transition System Specifications (TS ..."
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Cited by 6 (1 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 [62]. Subsequently, the format of SOS rules became the object of study. Using socalled Transition System Specifications (TSS’s) several authors syntactically restricted the format of rules and showed several useful properties about the semantics induced by any TSS adhering to the format. This has resulted in a line of research proposing several syntactical rule formats and associated metatheorems. Properties that are guaranteed by such rule formats range from welldefinedness of the operational semantics and compositionality of behavioral equivalences to security and probabilityrelated issues. In this paper, we provide an initial hierarchy of SOS rules formats and metatheorems formulated around them.
Congruence Proofs For Weak Bisimulation on Higherorder Processes: Results for Typed omegaorder Calculi
, 1996
"... Congruence proofs for bisimulation on higherorder process calculi tend to be significantly more complex than their counterparts in firstorder process algebra frameworks. Moreover, a standard technique that allows us to cover strong forms of bisimulation on higherorder calculi seems to fail for th ..."
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Cited by 4 (1 self)
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Congruence proofs for bisimulation on higherorder process calculi tend to be significantly more complex than their counterparts in firstorder process algebra frameworks. Moreover, a standard technique that allows us to cover strong forms of bisimulation on higherorder calculi seems to fail for the corresponding weak forms. Similar problems are posed by applicative simulation on calculi and our starting point is a general and elegant technique for solving them that has been invented by Howe. We adapt and extend this technique to prove two new congruence results for !order process calculi. In the first case, where we use a static scoping discipline for action names, we treat a delay variant of late weak context bisimulation; in the second case, where we use a dynamic scoping discipline, we treat an early weak higherorder bisimulation. The present paper supersedes parts of our technical report [BF95], where we have considered secondorder processes.
On the Bisimulation Theory and Axiomatization of Higherorder Process Calculi
"... Higherorder process calculi, for its abstraction capability and theoretical significance, have constantly been receiving much attention in the field of process calculi, and stand as a mathematical tool for describing and analyzing mobile systems with dynamically changing interconnection structures ..."
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Cited by 3 (0 self)
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Higherorder process calculi, for its abstraction capability and theoretical significance, have constantly been receiving much attention in the field of process calculi, and stand as a mathematical tool for describing and analyzing mobile systems with dynamically changing interconnection structures. In this thesis we contribute to the higherorder paradigm in several aspects. • Higherorder πcalculus with mismatch: the bisimulation theory. Linear fragment of higherorder πcalculus with mismatch: the axiomatization. The problem of the axiomatization of higherorder process calculi, such as higherorder πcalculus, is always a nontrivial one. However, it is important, both in theory and practice, to be able to decide whether two higherorder processes are equivalent with respect to some bisimulation, which needs an algorithm that can effectively analyze and give an answer efficiently. We further the available work by considering the higherorder πcalculus with mismatch, which is a useful operator in bisimulation theory and especially the axiomatization, from algorithmic point of view. We first formulate the bisimulation theory, where the bisimulation we define is called open weak higherorder bisimulation, which is a nondelayed
A Theory of Core Fudgets
 Proc. ICFP'98, ACM
, 1998
"... The Fudgets system is a toolkit for developing graphical applications in the lazy functional programming language Haskell. In this paper we develop an operational semantics for a subset of this system, inspired by ideas from concurrency theory. A semantic theory based on bisimulation is defined and ..."
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Cited by 1 (0 self)
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The Fudgets system is a toolkit for developing graphical applications in the lazy functional programming language Haskell. In this paper we develop an operational semantics for a subset of this system, inspired by ideas from concurrency theory. A semantic theory based on bisimulation is defined and shown to be a congruence. We consider two applications of this theory: firstly, some equational rules useful for reasoning about Fudget programs are verified; secondly, we show how the operational semantics can be used to check the correctness of implementations of the Fudgets system. 1 Introduction The Fudgets system [11] is one of a number of systems for building graphical applications in lazy functional programming languages such as Haskell [24]. A program in the Fudgets system is composed of a collection of fudgets, which correspond closely to concurrent processes in a process network. Fudgets can communicate with one another and also with the window system, and correspond to graphical...