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15
Proving Properties of Dynamic Process Networks
, 1998
"... We present the first compositional proof system for checking processes against formulas in the modal ¯calculus which is capable of handling dynamic process networks. The proof system is obtained in a systematic way from the operational semantics of the underlying process algebra. A nontrivial proo ..."
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Cited by 16 (8 self)
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We present the first compositional proof system for checking processes against formulas in the modal ¯calculus which is capable of handling dynamic process networks. The proof system is obtained in a systematic way from the operational semantics of the underlying process algebra. A nontrivial proof example is given, and the proof system is shown to be sound in general, and complete for finitestate processes. 1 Introduction In this paper we address the problem of verifying modal ¯calculus properties of general infinitestate processes, and we present what we believe to be the first genuinely compositional solution to this problem. The value of compositionality in program logics is well established. Compositionality allows better structuring and decomposition of the verification task, it allows reuse of proofs, and it allows reasoning about partially instantiated programs, thus supporting program synthesis. Even more fundamentally it allows, at least in principle, verification exe...
Proving Trust in Systems of SecondOrder Processes: Preliminary results
 In Proceedings of the 31th Hawaii International Conference on System Sciences, volume VII
, 1997
"... We consider the problem of proving correctness properties for concurrent systems with features such as higherorder communication and dynamic resource generation. As examples we consider operational models of security and authentication protocols based on the higherorder calculus. In the setting ..."
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Cited by 13 (1 self)
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We consider the problem of proving correctness properties for concurrent systems with features such as higherorder communication and dynamic resource generation. As examples we consider operational models of security and authentication protocols based on the higherorder calculus. In the setting we propose key features such as nonces/time stamps, encryption /decryption, and key generation can be modelled in a simple and abstract fashion using channel name generation and secondorder process communication. A temporal logic is proposed as an appropriate logic to express crucial correctness properties such as secrecy and authenticity. The logic is based on the modal calculus with only greatest fixed points and universal nextstate quantification, extended with firstorder features to deal with names, and secondorder features including function space constructions to deal with process input and output. A difficulty is that formulas need recursion in both covariant and contravariant po...
Compositional Verification of CCS Processes
, 1999
"... . We present a proof system for verifying CCS processes in the modal ¯calculus. Its novelty lies in the generality of the proof judgements allowing parametric and compositional reasoning in this complex setting. This is achieved, in part, by the use of explicit fixed point ordinal approximations, a ..."
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Cited by 8 (4 self)
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. We present a proof system for verifying CCS processes in the modal ¯calculus. Its novelty lies in the generality of the proof judgements allowing parametric and compositional reasoning in this complex setting. This is achieved, in part, by the use of explicit fixed point ordinal approximations, and in part by a complete separation, following an approach by Simpson, of rules concerning the logic from the rules encoding the operational semantics of the process language. 1 Introduction In a number of recent papers [14, 9] prooftheoretical frameworks for compositional verification have been put forward based on Gentzenstyle sequents of the shape \Gamma ` \Delta, where the components of \Gamma and \Delta are correctness assertions P : OE. Several programming or modelling languages have been considered, including CCS [3], the ßcalculus [2], CHOCS [1], general GSOSdefinable languages [9], and even a significant core fragment of a real programming language, Erlang [4]. An important ...
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.
μCalculus with Explicit Points and Approximations
 Journal of Logic and Computation
, 1999
"... . We present a Gentzenstyle sequent calculus for program verification which accomodates both model checkinglike verification based on global state space exploration, and compositional reasoning. To handle the complexities arrising from the presence of fixedpoint formulas, programs with dynamicall ..."
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Cited by 3 (0 self)
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. We present a Gentzenstyle sequent calculus for program verification which accomodates both model checkinglike verification based on global state space exploration, and compositional reasoning. To handle the complexities arrising from the presence of fixedpoint formulas, programs with dynamically evolving architecture, and cut rules we use transition assertions, and introduce fixedpoint approximants explicitly into the assertion language. We address, in a gamebased manner, the semantical basis of this approach, as it applies to the entailment subproblem. Soundness and completeness results are obtained, and examples are shown illustrating some of the concepts. Keywords: mucalculus, sequent calculus, program verification, compositionality. 1 Introduction In this paper we study program verification in terms of provability of general sequents of the shape \Gamma ` \Delta; (1) where the components of \Gamma and \Delta can be temporal correctness assertions P : OE. Since program ...
µCalculus with Explicit Points and Approximations
, 2000
"... We present a Gentzenstyle sequent calculus for program verification which accomodates both model checkinglike verification based on global state space exploration, and compositional reasoning. To handle the complexities arrising from the presence of fixedpoint formulas, programs with dynamically ..."
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Cited by 3 (1 self)
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We present a Gentzenstyle sequent calculus for program verification which accomodates both model checkinglike verification based on global state space exploration, and compositional reasoning. To handle the complexities arrising from the presence of fixedpoint formulas, programs with dynamically evolving architecture, and cut rules we use transition assertions, and introduce fixedpoint approximants explicitly into the assertion language. We address, in a gamebased manner, the semantical basis of this approach, as it applies to the entailment subproblem. Soundness and completeness results are obtained, and examples are shown illustrating some of the concepts.
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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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 synergy between modelchecking and type inference for the verification of valuepassing higherorder processes
 In Proceedings of AMAST’98
, 1999
"... Abstract. In this paper, we present a formal verification framework for higherorder valuepassing process algebra. This framework stems from an established synergy between type inference and modelchecking. The language considered here is based on a sugared version of an implicitly typed λcalculus ..."
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Abstract. In this paper, we present a formal verification framework for higherorder valuepassing process algebra. This framework stems from an established synergy between type inference and modelchecking. The language considered here is based on a sugared version of an implicitly typed λcalculus extended with higherorder synchronous concurrency primitives. First, we endow such a syntax with a semantic theory made of a static semantics together with a dynamic semantics. The static semantics consists of an annotated type system. The dynamic semantics is operational and comes as a twolayered labeled transition system. The dynamic semantics is abstracted into a transitional semantics so as to make finite some infinitestate processes. We describe the syntax and the semantics of a verification logic that allows one to specify properties. The logic is an extension of the modal µcalculus for handling higherorder processes, valuepassing and return of results. 1
Toward a Bisimulation Theory for Linear HigherOrder πCalculus
, 2007
"... Abstract. Higherorder process calculi have been receiving much attention in recent years for its significance in both theorey and practice. Work on bisimulations has never ceased evolving, typically represented by Thomsen and Sangiorgi for their work on bisimulation theory and encoding to and from ..."
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Cited by 1 (1 self)
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Abstract. Higherorder process calculi have been receiving much attention in recent years for its significance in both theorey and practice. Work on bisimulations has never ceased evolving, typically represented by Thomsen and Sangiorgi for their work on bisimulation theory and encoding to and from firstorder process calculi. Fu puts forth linear higherorder πcalculus, and makes improvement to previous work on bisimulation and builds a sound and complete equation system by exploitng linearity of processes, which takes resource sensitiveness into account. In this paper, we establish some recent result on bisimulation theory in linear higherorder πcalculus. By exploiting the properties of linear highorder processes, we work out two simpler variants than local bisimulation, which is an intuitive observational equivalence, and they both coincide with local bisimilarity. The first variant, called local linear bisimulation, simplifies the matching of higherorder input and higherorder output based on the feature of checking equivalence with some special processes (in input or output) instead of general ones. The second variant, called local linear variant bisimulation, rewrites the firstorder bound output clause in local bisimulation in some more suitable form for some application on it, by harnessing the congruence properties. We also mention some future work in the conclusion. Key words: Bisimulation, Linear, Higherorder, πCalculus, Process calculi 1
Logical and Operational Methods in the Analysis of Programs and Systems
"... Interpretation [25], Modalities in Analysis and Verification [30], and Enhanced Operational Semantics [35]. Each section below begins with a presentation of our view of the stateoftheart within the area, and ends with a brief explanation of how the papers in these proceedings enhance our knowledg ..."
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Interpretation [25], Modalities in Analysis and Verification [30], and Enhanced Operational Semantics [35]. Each section below begins with a presentation of our view of the stateoftheart within the area, and ends with a brief explanation of how the papers in these proceedings enhance our knowledge of the area. Integration of Programming Paradigms Programming notions can be expressed in many di erent paradigms  imperative, objectoriented, concurrent, functional, logicprogramming, constraint, etc. It is widely agreed that each programming paradigm has its own merits and is particularly appropriate for expressing certain classes of computation, thus the choice of paradigm can greatly affect the ease of programming. Traditionally, when constructing large scale systems, in particular distributed systems, it is often necessary to use multiple programming styles with disparate programming models, and very often it is necessary to resolve conflicts by low level methods reverting to the lowest...