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284
The synchronous dataflow programming language LUSTRE
- Proceedings of the IEEE
, 1991
"... This paper describes the language Lustre, which is a dataflow synchronous language, designed for programming reactive systems --- such as automatic control and monitoring systems --- as well as for describing hardware. The dataflow aspect of Lustre makes it very close to usual description tools in t ..."
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Cited by 646 (50 self)
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This paper describes the language Lustre, which is a dataflow synchronous language, designed for programming reactive systems --- such as automatic control and monitoring systems --- as well as for describing hardware. The dataflow aspect of Lustre makes it very close to usual description tools in these domains (block-diagrams, networks of operators, dynamical samples-systems, etc: : : ), and its synchronous interpretation makes it well suited for handling time in programs. Moreover, this synchronous interpretation allows it to be compiled into an efficient sequential program. Finally, the Lustre formalism is very similar to temporal logics. This allows the language to be used for both writing programs and expressing program properties, which results in an original program verification methodology. 1 Introduction Reactive systems Reactive systems have been defined as computing systems which continuously interact with a given physical environment, when this environment is unable to sy...
Functional Reactive Animation
, 1997
"... Fran (Functional Reactive Animation) is a collection of data types and functions for composing richly interactive, multimedia animations. The key ideas in Fran are its notions of behaviors and events. Behaviors are time-varying, reactive values, while events are sets of arbitrarily complex condition ..."
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Cited by 284 (30 self)
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Fran (Functional Reactive Animation) is a collection of data types and functions for composing richly interactive, multimedia animations. The key ideas in Fran are its notions of behaviors and events. Behaviors are time-varying, reactive values, while events are sets of arbitrarily complex conditions, carrying possibly rich information. Most traditional values can be treated as behaviors, and when images are thus treated, they become animations. Although these notions are captured as data types rather than a programming language, we provide them with a denotational semantics, including a proper treatment of real time, to guide reasoning and implementation. A method to e#ectively and efficiently perform event detection using interval analysis is also described, which relies on the partial information structure on the domain of event times. Fran has been implemented in Hugs, yielding surprisingly good performance for an interpreter-based system. Several examples are given, including the ability to describe physical phenomena involving gravity, springs, velocity, acceleration, etc. using ordinary di#erential equations.
Translation Validation
, 1998
"... We present the notion of translation validation as a new approach to the verification of translators (compilers, code generators). Rather than proving in advance that the compiler always produces a target code which correctly implements the source code (compiler verification), each individual transl ..."
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Cited by 184 (10 self)
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We present the notion of translation validation as a new approach to the verification of translators (compilers, code generators). Rather than proving in advance that the compiler always produces a target code which correctly implements the source code (compiler verification), each individual translation (i.e. a run of the compiler) is followed by a validation phase which verifies that the target code produced on this run correctly implements the submitted source program. Several ingredients are necessary to set up the -- fully automatic -- translation validation process, among which are: 1. A common semantic framework for the representation of the source code and the generated target code. 2. A formalization of the notion of "correct implementation" as a refinement relation. 3. A syntactic simulation-based proof method which allows to automatically verify that one model of the semantic framework, representing the produced target code, correctly implements another model which repres...
An overview and synthesis on timed process algebras
, 1991
"... We present anoverview and synthesis of existing results about process algebras for the speci cation and analysis of timed systems. The motivation is double: present anoverview of some relevant and representative approaches and suggest a unifying framework for them. time, we propose a general model f ..."
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Cited by 169 (4 self)
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We present anoverview and synthesis of existing results about process algebras for the speci cation and analysis of timed systems. The motivation is double: present anoverview of some relevant and representative approaches and suggest a unifying framework for them. time, we propose a general model for them: transition systems whose labels are either elements ofavocabulary of actions or elements of a time domain. Many properties of this model are studied concerning their impact on description capabilities and on realisability issues. An overview of the language features of the process algebras considered is presented, by focusing on constructs used to express time constraints. The presentation is organised as an exercise of building a timed process algebra from a standard process algebra for untimed systems. The overview is completed by a discussion about description capabilities according to semantic and pragmatic criteria. 1
The synchronous languages twelve years later
- PROCEEDINGS OF THE IEEE
, 2003
"... Twelve years ago, Proceedings of the IEEE devoted a special section to the synchronous languages. This article discusses the improvements, difficulties, and successes that have occured with the synchronous languages since then. Today, synchronous languages have been established as a technology of c ..."
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Cited by 155 (11 self)
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Twelve years ago, Proceedings of the IEEE devoted a special section to the synchronous languages. This article discusses the improvements, difficulties, and successes that have occured with the synchronous languages since then. Today, synchronous languages have been established as a technology of choice for modeling, specifying, validating, and implementing real-time embedded applications. The paradigm of synchrony has emerged as an engineer-friendly design method based on mathematically-sound tools.
What Good Are Digital Clocks?
, 1992
"... . Real-time systems operate in "real," continuous time and state changes may occur at any real-numbered time point. Yet many verification methods are based on the assumption that states are observed at integer time points only. What can we conclude if a real-time system has been shown ..."
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Cited by 141 (14 self)
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. Real-time systems operate in "real," continuous time and state changes may occur at any real-numbered time point. Yet many verification methods are based on the assumption that states are observed at integer time points only. What can we conclude if a real-time system has been shown "correct" for integral observations? Integer time verification techniques suffice if the problem of whether all real-numbered behaviors of a system satisfy a property can be reduced to the question of whether the integral observations satisfy a (possibly modified) property. We show that this reduction is possible for a large and important class of systems and properties: the class of systems includes all systems that can be modeled as timed transition systems; the class of properties includes time-bounded invariance and time-bounded response. 1 Introduction Over the past few years, we have seen a proliferation of formal methodologies for software and hardware design that emphasize the treatm...
Distributed control applications within sensor networks
- IEEE PROCEEDINGS SPECIAL ISSUE ON DISTRIBUTED SENSOR NETWORKS
, 2003
"... Sensor networks are gaining a central role in the research community. This paper addresses some of the issues arising from the use of sensor networks in control applications. Classical control theory proves to be insufficient in modeling distributed control problems where issues of communication del ..."
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Cited by 102 (27 self)
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Sensor networks are gaining a central role in the research community. This paper addresses some of the issues arising from the use of sensor networks in control applications. Classical control theory proves to be insufficient in modeling distributed control problems where issues of communication delay, jitter, and time synchronization between components are not negligible. After discussing our hardware and software platform and our target application, we review useful models of computation and then suggest a mixed model for design, analysis, and synthesis of control algorithms within sensor networks. We present a hierarchical model composed of continuous time-trigger components at the low level and discrete event-triggered components at the high level.
Programming and verifying real-time systems by means of the synchronous data-flow language LUSTRE
, 1994
"... We investigate the benefits of using a synchronous data-flow language for programming critical real-time systems. These benefits concern ergonomy --- since the dataflow approach meets traditional description tools used in this domain ---, and ability to support formal design and verification methods ..."
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Cited by 102 (11 self)
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We investigate the benefits of using a synchronous data-flow language for programming critical real-time systems. These benefits concern ergonomy --- since the dataflow approach meets traditional description tools used in this domain ---, and ability to support formal design and verification methods. We show, on a simple example, how the language Lustre and its associated verification tool Lesar, can be used to design a program, to specify its critical properties, and to verify these properties. As the language Lustre and its use have been already published in several papers (e.g., [11, 18]), we put particular emphasis on program verification. A preliminary version of this paper has been published in [28]. 1 Introduction It is useless to repeat why real-time programs are among those in which errors can have the most dramatic consequences. Thus, these programs constitute a domain where there is a special need of rigorous design methods. We advocate a "language approach" to this problem...
Testing can be formal, too
, 1995
"... Abstract. The paper presents a theory of program testing based on formal specifications. The formal semantics of the specifications is the basis for a notion of an exhaustive test set. Under some minimal hypotheses on the program under test, the success of this test set is equivalent to the satisfac ..."
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Cited by 98 (2 self)
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Abstract. The paper presents a theory of program testing based on formal specifications. The formal semantics of the specifications is the basis for a notion of an exhaustive test set. Under some minimal hypotheses on the program under test, the success of this test set is equivalent to the satisfaction of the specification. The selection of a finite subset of the exhaustive test set can be seen as the introduction of more hypotheses on the program, called selection hypotheses. Several examples of commonly used selection hypotheses are presented. Another problem is the observability of the results of a program with respect to its specification: contrary to some common belief, the use of a formal specification is not always sufficient to decide whether a test execution is a success. As soon as the specification deals with more abstract entities than the program, program results may appear in a form which is not obviously equivalent to the specificied results. A solution to this problem is proposed in the case of algebraic specifications. 1
Operational and Compositional Semantics of Synchronous Automaton Compositions
, 1992
"... : The state/transition paradigm has been used extensively for the description of event-driven, parallel systems. However, the lack for hierarchic structure in such descriptions usually prevents us from using this paradigm in a real programming language. We propose the Argos language for reactive ..."
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Cited by 95 (15 self)
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: The state/transition paradigm has been used extensively for the description of event-driven, parallel systems. However, the lack for hierarchic structure in such descriptions usually prevents us from using this paradigm in a real programming language. We propose the Argos language for reactive systems. The basic components of a program are input/output-labeled transition systems verifying reactivity (a property similar to input-enabling in IOautomata) . The composition operations (parallel composition and refinement, providing hierarchy) are based upon the synchronous broadcast mechanism of Esterel. We define the language formally in an algebraic framework, and give an operational semantics. The main result is the compositionality of the semantics; we prove that the bisimulation of models induces an equivalence which is a congruence for the operators we propose. An interesting point is the way we introduce hierarchy in a compositional way. 1 1 Introduction The problem ...
