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Generalised Coinduction
, 2001
"... We introduce the lambdacoiteration schema for a distributive law lambda of a functor T over a functor F. Under certain conditions it can be shown to uniquely characterise functions into the carrier of a final Fcoalgebra, generalising the basic coiteration schema as given by finality. The duals of ..."
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Cited by 28 (3 self)
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We introduce the lambdacoiteration schema for a distributive law lambda of a functor T over a functor F. Under certain conditions it can be shown to uniquely characterise functions into the carrier of a final Fcoalgebra, generalising the basic coiteration schema as given by finality. The duals of primitive recursion and courseofvalue iteration, which are known extensions of coiteration, arise as instances of our framework. One can furthermore obtain schemata justifying recursive specifications that involve operators such as addition of power series, regular operators on languages, or parallel and sequential composition of processes. Next...
A congruence rule format for namepassing process calculi from mathematical structural operational semantics
 In Proc. LICS’06
, 2006
"... We introduce a GSOSlike rule format for namepassing process calculi. Specifications in this format correspond to theories in nominal logic. The intended models of such specifications arise by initiality from a general categorical model theory. For operational semantics given in this rule format, a ..."
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Cited by 26 (5 self)
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We introduce a GSOSlike rule format for namepassing process calculi. Specifications in this format correspond to theories in nominal logic. The intended models of such specifications arise by initiality from a general categorical model theory. For operational semantics given in this rule format, a natural behavioural equivalence — a form of open bisimilarity — is a congruence.
A menagerie of nonfinitely based process semantics over BPA*—from ready simulation to completed traces
 Mathematical Structures in Computer Science
, 1998
"... Fokkink and Zantema ((1994) Computer Journal 37:259–267) have shown that bisimulation equivalence has a finite equational axiomatization over the language of Basic Process Algebra with the binary Kleene star operation (BPA ∗). In the light of this positive result on the mathematical tractability of ..."
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Cited by 23 (18 self)
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Fokkink and Zantema ((1994) Computer Journal 37:259–267) have shown that bisimulation equivalence has a finite equational axiomatization over the language of Basic Process Algebra with the binary Kleene star operation (BPA ∗). In the light of this positive result on the mathematical tractability of bisimulation equivalence over BPA ∗ , a natural question to ask is whether any other (pre)congruence relation in van Glabbeek’s linear time/branching time spectrum is finitely (in)equationally axiomatizable over it. In this paper, we prove that, unlike bisimulation equivalence, none of the preorders and equivalences in van Glabbeek’s linear time/branching time spectrum, whose discriminating power lies in between that of ready simulation and that of completed traces, has a finite equational axiomatization. This we achieve by exhibiting a family of (in)equivalences that holds in ready simulation semantics, the finest semantics that we consider, whose instances cannot all be proven by means of any finite set of (in)equations
Trace Semantics for Coalgebras
, 2003
"... Traditionally, traces are the sequences of labels associated with paths in transition systems X # P(A X). ..."
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Cited by 23 (7 self)
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Traditionally, traces are the sequences of labels associated with paths in transition systems X # P(A X).
A FrontEnd Generator for Verification Tools
, 1995
"... This paper describes the Process Algebra Compiler (PAC), a frontend generator for processalgebrabased verification tools. Given descriptions of a process algebra's concrete and abstract syntax and semantics as structural operational rules, the PAC produces syntactic routines and functions fo ..."
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Cited by 22 (5 self)
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This paper describes the Process Algebra Compiler (PAC), a frontend generator for processalgebrabased verification tools. Given descriptions of a process algebra's concrete and abstract syntax and semantics as structural operational rules, the PAC produces syntactic routines and functions for computing the semantics of programs in the algebra. Using this tool greatly simplies the task of adapting verification tools to the analysis of systems described in different languages; it may therefore be used to achieve sourcelevel compatibility between different verication tools. Although the initial verication tools targeted by the PAC are MAUTO and the Concurrency Workbench, the structure of the PAC caters for the support of other tools as well.
Bisimilarity of Open Terms
, 2000
"... Traditionally, in process calculi, relations over open terms, i.e., terms with free process variables, are defined as extensions of closedterm relations: two open terms are related if and only if all their closed instantiations are related. Working in the context of bisimulation, in this paper we s ..."
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Traditionally, in process calculi, relations over open terms, i.e., terms with free process variables, are defined as extensions of closedterm relations: two open terms are related if and only if all their closed instantiations are related. Working in the context of bisimulation, in this paper we study a different approach; we define semantic models for open terms, socalled conditional transition systems, and define bisimulation directly on those models. It turns out that this can be done in at least two different ways, one giving rise to De Simone's formal hypothesis bisimilarity and the other to a variation which we call hypothesispreserving bisimilarity (denoted t fh and t hp, respectively). For open terms, we have (strict) inclusions t fh /t hp / t ci (the latter denoting the standard ``closed instance' ' extension); for closed terms, the three coincide. Each of these relations is a congruence in the usual sense. We also give an alternative characterisation of t hp in terms of nonconditional transitions, as substitutionclosed bisimilarity (denoted t sb). Finally, we study the issue of recursion congruence: we prove that each of the above relations is a congruence with respect to the recursion operator; however, for t ci this result holds under more restrictive conditions than for tfh and thp.]