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107
Proving the correctness of reactive systems using sized types
, 1996
"... { rjmh, pareto, sabry We have designed and implemented a typebased analysis for proving some baaic properties of reactive systems. The analysis manipulates rich type expressions that contain information about the sizes of recursively defined data structures. Sized types are useful for detecting d ..."
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Cited by 122 (2 self)
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{ rjmh, pareto, sabry We have designed and implemented a typebased analysis for proving some baaic properties of reactive systems. The analysis manipulates rich type expressions that contain information about the sizes of recursively defined data structures. Sized types are useful for detecting deadlocks, nontermination, and other errors in embedded programs. To establish the soundness of the analysis we have developed an appropriate semantic model of sized types. 1 Embedded Functional Programs In a reactive system, the control software must continuously react to inputs from the environment. We distinguish a class of systems where the embedded programs can be naturally expressed as functional programs manipulating streams. This class of programs appears to be large enough for many purposes [2] and is the core of more expressive formalisms that accommodate asynchronous events, nondeterminism, etc. The fundamental criterion for the correctness of programs embedded in reactive systems is Jwene.ss. Indeed, before considering the properties of the output, we must ensure that there is some output in the first place: the program must continuous] y react to the input streams by producing elements on the output streams. This latter property may fail in various ways: e the computation of a stream element may depend on itself creating a “black hole, ” or e the computation of one of the output streams may demand elements from some input stream at different rates, which requires unbounded buffering, or o the computation of a stream element may exhaust the physical resources of the machine or even diverge.
Modeling Languages: Syntax, Semantics and All That Stuff Part I: The Basic Stuff
, 2000
"... The motivation for this paper, the first in a planned series of three parts, is the multitude of concepts surrounding the proper definition of complex modeling languages for systems and software, and the confusion that this often causes. ..."
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Cited by 60 (1 self)
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The motivation for this paper, the first in a planned series of three parts, is the multitude of concepts surrounding the proper definition of complex modeling languages for systems and software, and the confusion that this often causes.
Towards a Formalization of the Unified Modeling Language
 IN PROCEEDINGS OF ECOOP'97
, 1997
"... The Unified Modeling Language UML is a language for specifying, visualizing and documenting objectoriented systems. UML combines the concepts of OOA/OOD, OMT and OOSE and is intended as a standard in the domain of objectoriented analysis and design. Due to the missing formal, mathematical found ..."
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Cited by 48 (3 self)
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The Unified Modeling Language UML is a language for specifying, visualizing and documenting objectoriented systems. UML combines the concepts of OOA/OOD, OMT and OOSE and is intended as a standard in the domain of objectoriented analysis and design. Due to the missing formal, mathematical foundation of UML the syntax and the semantics of a number of UML constructs are not precisely defined.
Consistent Graphical Specification of Distributed Systems
 INDUSTRIAL APPLICATIONS AND STRENGTHENED FOUNDATIONS OF FORMAL METHODS (FME’97), LNCS 1313
, 1997
"... The widely accepted possible benefits of formal methods on the one hand and their minor use compared to informal or graphical description techniques on the other hand have repeatedly lead to the claim that formal methods should be put to a more indirect or transparent use. We show how such an ind ..."
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Cited by 38 (12 self)
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The widely accepted possible benefits of formal methods on the one hand and their minor use compared to informal or graphical description techniques on the other hand have repeatedly lead to the claim that formal methods should be put to a more indirect or transparent use. We show how such an indirect approach can be incorporated in a CASE tool prototype by basing it upon formally defined hierarchical description techniques. We demonstrate the immediate benefits by introducing consistency notions gained from the formalization. Additionally,
AutoFocus  A Tool for Distributed Systems Specification
 PROCEEDINGS FTRTFT’96  FORMAL TECHNIQUES IN REALTIME AND FAULTTOLERANT SYSTEMS
, 1996
"... We describe the concept of AutoFocus a tool for the specification of distributed systems. AutoFocus is based ..."
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Cited by 33 (4 self)
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We describe the concept of AutoFocus a tool for the specification of distributed systems. AutoFocus is based
A streambased mathematical model for distributed information processing systems  SysLab system model
, 1996
"... ..."
HOLCF: Higher Order Logic of Computable Functions
 In Theorem Proving in Higher Order Logics, volume 971 of LNCS
, 1995
"... . This paper presents a survey of HOLCF, a higher order logic of computable functions. The logic HOLCF is based on HOLC, a variant of the well known higher order logic HOL, which offers the additional concept of type classes. HOLCF extends HOLC with concepts of domain theory such as complete pa ..."
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Cited by 24 (0 self)
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. This paper presents a survey of HOLCF, a higher order logic of computable functions. The logic HOLCF is based on HOLC, a variant of the well known higher order logic HOL, which offers the additional concept of type classes. HOLCF extends HOLC with concepts of domain theory such as complete partial orders, continuous functions and a fixed point operator. With the help of type classes the extension can be formulated in a way such that the logic LCF constitutes a proper sublanguage of HOLCF. Therefore techniques from higher order logic and LCF can be combined in a fruitful manner avoiding drawbacks of both logics. The development of HOLCF was entirely conducted within the Isabelle system. 1 Introduction This paper presents a survey of HOLCF, a higher order logic of computable functions. The logic HOLCF is based on HOLC, a variant of the well known higher order logic HOL [GM93], which offers the additional concept of type classes. HOLCF extends HOLC with concepts of domain t...
State Transition Diagrams
, 1996
"... In this paper, we present a general concept of state transition diagrams wellsuited for various modeling purposes. Our notation is tailored for the description of asynchronous timeindependent agents. We start by proposing a graphical and textual syntax, and define an abstract syntax for both no ..."
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Cited by 23 (9 self)
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In this paper, we present a general concept of state transition diagrams wellsuited for various modeling purposes. Our notation is tailored for the description of asynchronous timeindependent agents. We start by proposing a graphical and textual syntax, and define an abstract syntax for both notations. The semantics of state transition diagrams defined by translating the abstract syntax into timed port automata and to timed input/output relations on streams. To make the graphical notation practical, we partition the (possibly infinite) state space of the state transition diagrams with state predicates and define transitions with pre and postconditions.
Enhancing the SYSLAB System Model with State
, 1996
"... In this report, the SysLab system model is complemented in different ways: Statebox models are provided through timed port automata, for which an operational and a corresponding denotational semantics are given. Composition is defined for components modeled in the statebox view as well as for co ..."
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Cited by 22 (12 self)
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In this report, the SysLab system model is complemented in different ways: Statebox models are provided through timed port automata, for which an operational and a corresponding denotational semantics are given. Composition is defined for components modeled in the statebox view as well as for components modeled in the black ox view. This composition is welldefined for networks of infinitely many components. To show the applicability of the model, several examples are given.
A Denotational Model for Mobile PointtoPoint Dataflow Networks with Channel Sharing
, 1997
"... We present a fully abstract, denotational model for mobile, timed, nondeterministic dataflow networks whose components communicate in a pointtopoint fashion. In this model components and networks of components are represented by sets of stream processing functions. Each stream processing function ..."
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Cited by 22 (8 self)
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We present a fully abstract, denotational model for mobile, timed, nondeterministic dataflow networks whose components communicate in a pointtopoint fashion. In this model components and networks of components are represented by sets of stream processing functions. Each stream processing function is required to be strongly pulsedriven and privacy preserving. A function is strongly pulsedriven if it is contractive with respect to the metric on streams. This property guarantees the existence of unique fixpoints. The privacy preservation property can be thought of as an invariant specific to mobile pointtopoint systems. Firstly, it guarantees that a function never accesses, depends on or forwards a port whose name it does not already know. Secondly, it guarantees that at the same point in time no port is known to more than two components, namely the sender and the receiver. Our model allows the description of a wide variety of networks  in particular, the description of unbounded nondeterministic networks. We demonstrate some features of our model by specifying a communication central.