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Petrify: a tool for manipulating concurrent specifications and . . .
"... Petrify is a tool for (1) manipulating concurrent specifications and (2) synthesis and optimization of asynchronous control circuits. Given a Petri Net (PN), a Signal Transition Graph (STG), or a Transition System (TS) 1 it (1) generates another PN or STG which is simpler than the original descripti ..."
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Cited by 219 (34 self)
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Petrify is a tool for (1) manipulating concurrent specifications and (2) synthesis and optimization of asynchronous control circuits. Given a Petri Net (PN), a Signal Transition Graph (STG), or a Transition System (TS) 1 it (1) generates another PN or STG which is simpler than the original description and (2) produces an optimized netlist of an asynchronous controller in the target gate library while preserving the specified inputoutput behavior. Given a specification petrify provides a designer with a netlist of an asynchronous circuit and a PNlike description of the circuit behavior in terms of events and ordering relations between events. The latter ability of backannotating to the specification level helps the designer to control the design process. For transforming a specification petrify performs a token flow analysis of the initial PN and produces a transition system (TS). In the initial TS, all transitions with the same label are considered as one event. The TS is then transformed and transitions relabeled to fulfill the conditions required to obtain a safe irredundant PN. For synthesis of an asynchronous implementation petrify performs state assignment by solving the Complete State Coding problem. State assignment is coupled with logic minimization and speedindependent technology mapping to a target library. The final netlist is guaranteed to be speedindependent, i.e., hazardfree under any distribution of gate delays and multiple input changes satisfying the initial specification. The tool has been used for synthesis of PNs and PNs composition [10], synthesis [7, 9, 8] and resynthesis [29] of asynchronous controllers and can be also applied in areas related with the analysis of concurrent programs. This paper provides an overview of petrify and the theory behind its main functions.
A Calculus of Mobile Processes, Part I
 I AND II. INFORMATION AND COMPUTATION
, 1989
"... We present the ßcalculus, a calculus of communicating systems in which one can naturally express processes which have changing structure. Not only may the component agents of a system be arbitrarily linked, but a communication between neighbours may carry information which changes that linkage. The ..."
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Cited by 219 (4 self)
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We present the ßcalculus, a calculus of communicating systems in which one can naturally express processes which have changing structure. Not only may the component agents of a system be arbitrarily linked, but a communication between neighbours may carry information which changes that linkage. The calculus is an extension of the process algebra CCS, following work by Engberg and Nielsen who added mobility to CCS while preserving its algebraic properties. The ßcalculus gains simplicity by removing all distinction between variables and constants; communication links are identified by names, and computation is represented purely as the communication of names across links. After an illustrated description of how the ßcalculus generalises conventional process algebras in treating mobility, several examples exploiting mobility are given in some detail. The important examples are the encoding into the ß calculus of higherorder functions (the calculus and combinatory algebra), the tr...
Computing Simulations on Finite and Infinite Graphs
, 1996
"... . We present algorithms for computing similarity relations of labeled graphs. Similarity relations have applications for the refinement and verification of reactive systems. For finite graphs, we present an O(mn) algorithm for computing the similarity relation of a graph with n vertices and m edges ..."
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Cited by 195 (7 self)
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. We present algorithms for computing similarity relations of labeled graphs. Similarity relations have applications for the refinement and verification of reactive systems. For finite graphs, we present an O(mn) algorithm for computing the similarity relation of a graph with n vertices and m edges (assuming m n). For effectively presented infinite graphs, we present a symbolic similaritychecking procedure that terminates if a finite similarity relation exists. We show that 2D rectangular automata, which model discrete reactive systems with continuous environments, define effectively presented infinite graphs with finite similarity relations. It follows that the refinement problem and the 8CTL modelchecking problem are decidable for 2D rectangular automata. 1 Introduction A labeled graph G = (V; E;A; hh\Deltaii) consist of a (possibly infinite) set V of vertices, a set E ` V 2 of edges, a set A of labels, and a function hh\Deltaii : V ! A that maps each vertex v to a label hh...
Reactive, Generative and Stratified Models of Probabilistic Processes
 Information and Computation
, 1990
"... ion Let E; E 0 be PCCS expressions. The intermodel abstraction rule IMARGR is defined by E ff[p] \Gamma\Gamma! i E 0 =) E ff[p= G (E;fffg)] ae \Gamma\Gamma\Gamma\Gamma\Gamma\Gamma! i E 0 This rule uses the generative normalization function to convert generative probabilities to reactive ..."
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Cited by 195 (8 self)
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ion Let E; E 0 be PCCS expressions. The intermodel abstraction rule IMARGR is defined by E ff[p] \Gamma\Gamma! i E 0 =) E ff[p= G (E;fffg)] ae \Gamma\Gamma\Gamma\Gamma\Gamma\Gamma! i E 0 This rule uses the generative normalization function to convert generative probabilities to reactive ones, thereby abstracting away from the relative probabilities between different actions. We can now define 'GR ('G (P )) as the reactive transition system that can be inferred from P 's generative transition system via IMARGR . By the same procedure as described at the end of Section 3.1, 'GR can be extended to a mapping 'GR : j GG ! j GR . Write P GR ¸ Q if P; Q 2 Pr are reactive bisimulation equivalent with respect to the transitions derivable from G+IMARGR , i.e. the theory obtained by adding IMARGR to the rules of Figure 7. The equivalence GR ¸ is defined just like R ¸ but using the cPDF ¯GR instead of ¯R . ¯GR is defined by ¯GR (P; ff; S) = X i2I R (=I G ) fj p i j G+ I...
Bisimulation for Labelled Markov Processes
 INFORMATION AND COMPUTATION
, 1997
"... In this paper we introduce a new class of labelled transition systems  Labelled Markov Processes  and define bisimulation for them. Labelled Markov processes are ..."
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In this paper we introduce a new class of labelled transition systems  Labelled Markov Processes  and define bisimulation for them. Labelled Markov processes are
Analysis of Inheritance Anomaly in ObjectOriented Concurrent Programming Languages
, 1993
"... It has been pointed out that inheritance and synchronization constraints in concurrent object systems often conflict with each other, resulting in inheritance anomaly where redefinitions of inherited methods are necessary in order to maintain the integrity of concurrent objects. The anomaly is seri ..."
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Cited by 180 (2 self)
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It has been pointed out that inheritance and synchronization constraints in concurrent object systems often conflict with each other, resulting in inheritance anomaly where redefinitions of inherited methods are necessary in order to maintain the integrity of concurrent objects. The anomaly is serious, as it could nullify the benefits of inheritance altogether. Several proposals have been made for resolving the anomaly; however, we argue that those proposals suffer from the incompleteness which allows room for counterexamples. We give an overview and the analysis of inheritance anomaly, and review several proposals for minimizing the unwanted effect of this phenomenon. In particular, we propose (partial) solutions using (1) computational reflection, and (2) transactions in OOCP languages. 1 Introduction Inheritance is the prime language feature in sequential OO (ObjectOriented) languages, and is especially important for code reuse. Another important feature is concurrency; although...
Data flow analysis for verifying properties of concurrent programs
 In Proceedings of the Second ACM SIGSOFT Symposium on Foundations of Software Engineering
, 1994
"... Classification D.2.4 Software/Program Verification, D.1.3 Concurrent Programming This paper describes FLAVERS, a finitestate verification approach that analyzes whether concurrent systems satisfy userdefined, behavioral properties. FLAVERS automatically creates a compact, eventbased model of the ..."
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Cited by 176 (61 self)
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Classification D.2.4 Software/Program Verification, D.1.3 Concurrent Programming This paper describes FLAVERS, a finitestate verification approach that analyzes whether concurrent systems satisfy userdefined, behavioral properties. FLAVERS automatically creates a compact, eventbased model of the system that supports efficient dataflow analysis. FLAVERS achieves this efficiency at the cost of precision. Analysts, however, can improve the precision of analysis results by selectively and judiciously incorporating additional semantic information into an analysis. We report on an empirical study of the performance of the FLAVERS/Ada toolset applied to a collection of multitasking Ada systems. This study indicates that sufficient precision for proving system properties can usually be
The PEPA Workbench: A Tool to Support a Process Algebrabased Approach to Performance Modelling
 In Proceedings of the Seventh International Conference on Modelling Techniques and Tools for Computer Performance Evaluation, number 794 in Lecture Notes in Computer Science
, 1994
"... . In this paper we present a new technique for performance modelling and a tool supporting this approach. Performance Evaluation Process Algebra (PEPA) [1] is an algebraic language which can beused to build models of computer systems which capture information about the performance of the system. The ..."
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Cited by 174 (62 self)
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. In this paper we present a new technique for performance modelling and a tool supporting this approach. Performance Evaluation Process Algebra (PEPA) [1] is an algebraic language which can beused to build models of computer systems which capture information about the performance of the system. The PEPA language serves two purposes as a formal description language for computer system models. The performancerelated information in the model may be used to predict the performance of the system whereas the behavioural information in the model may be exploited when reasoning about the functional behaviour of the system (e.g. when finding deadlocks or when exhibiting equivalences between subcomponents). In this paper we concentrate on the performance aspects of the language. A method of reasoningaboutPEPA modelsproceedsby considering the derivation graph obtained from the model using the underlying operational semantics of the PEPA language. The derivation graph is systematically reduced ...