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100
The Esterel Synchronous Programming Language: Design, Semantics, Implementation
, 1992
"... this paper, we shall mostly be concerned by reactive kernels that constitute the central and most difficult part of reactive systems. In fact, ESTEREL is not a fullfledged programming language, but rather a program generator used to program reactive kernels in the same way as YACC [32] is used to p ..."
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Cited by 680 (10 self)
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this paper, we shall mostly be concerned by reactive kernels that constitute the central and most difficult part of reactive systems. In fact, ESTEREL is not a fullfledged programming language, but rather a program generator used to program reactive kernels in the same way as YACC [32] is used to program parsers from grammars. The interface and data handling must be specified in some host language. 1.2. Deterministic reactive programs Determinism is an important characteristic of reactive programs. A deterministic reactive program produces identical output sequences when fed with identical input sequences. All examples above are deterministic if physical time is considered as an input among others. The importance of determinism cannot be overestimated: deterministic systems are one order of magnitude simpler to specify, debug, and analyze than nondeterministic ones
LUSTRE: A declarative language for programming synchronous systems
 In 14th Symposium on Principles of Programming Languages (POPL’87). ACM
, 1987
"... LUSTRE is a synchronous dataflow language for programming syetema which interact. with their environments in realtime. After an informal presentation of the language, we describe its semantics by means of structural inference rules. Moreover, we ehow how to use this semantics in order to generate ..."
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Cited by 253 (18 self)
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LUSTRE is a synchronous dataflow language for programming syetema which interact. with their environments in realtime. After an informal presentation of the language, we describe its semantics by means of structural inference rules. Moreover, we ehow how to use this semantics in order to generate efficient, sequential code, namely, a finite state automaton which represents the control of the program. Formal rules for program transformation are also presented.
OneUnambiguous Regular Languages
 Information and computation
, 1997
"... The ISO standard for the Standard Generalized Markup Language (SGML) provides a syntactic metalanguage for the definition of textual markup systems. In the standard, the righthand sides of productions are based on regular expressions, although only regular expressions that denote words unambigu ..."
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Cited by 103 (9 self)
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The ISO standard for the Standard Generalized Markup Language (SGML) provides a syntactic metalanguage for the definition of textual markup systems. In the standard, the righthand sides of productions are based on regular expressions, although only regular expressions that denote words unambiguously, in the sense of the ISO standard, are allowed. In general, a word that is denoted by a regular expression is witnessed by a sequence of occurrences of symbols in the regular expression that match the word. In an unambiguous regular expression as defined by Book, Even, Greibach, and Ott, each word has at most one witness. But the SGML standard also requires that a witness be computed incrementally from the word with a onesymbol lookahead; we call such regular expressions 1unambiguous. A regular language is a 1unambiguous language if it is denoted by some 1unambiguous regular expression. We give a Kleene theorem for 1unambiguous languages and characterize 1unambiguous regu...
Regular Expressions into Finite Automata
 Theoretical Computer Science
, 1996
"... It is a wellestablished fact that each regular expression can be transformed into a nondeterministic finite automaton (NFA) with or without ffltransitions, and all authors seem to provide their own variant of the construction. Of these, Berry and Sethi [BS86] have shown that the construction of ..."
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Cited by 66 (5 self)
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It is a wellestablished fact that each regular expression can be transformed into a nondeterministic finite automaton (NFA) with or without ffltransitions, and all authors seem to provide their own variant of the construction. Of these, Berry and Sethi [BS86] have shown that the construction of an fflfree NFA due to to Glushkov [Glu61] is a natural representation of the regular expression, because it can be described in terms of the Brzozowski derivatives [Brz64] of the expression. Moreover, the Glushkov construction also plays a significant role in the document processing area: The SGML standard [ISO86], now widely adopted by publishing houses and government agencies for the syntactic specification of textual markup systems, uses deterministic regular expressions, i.e. expressions whose Glushkov automaton is deterministic, as a description language for document types. In this paper, we first show that the Glushkov automaton can be constructed in time quadratic in the size of the...
Automata and coinduction (an exercise in coalgebra
 LNCS
, 1998
"... The classical theory of deterministic automata is presented in terms of the notions of homomorphism and bisimulation, which are the cornerstones of the theory of (universal) coalgebra. This leads to a transparent and uniform presentation of automata theory and yields some new insights, amongst which ..."
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Cited by 63 (16 self)
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The classical theory of deterministic automata is presented in terms of the notions of homomorphism and bisimulation, which are the cornerstones of the theory of (universal) coalgebra. This leads to a transparent and uniform presentation of automata theory and yields some new insights, amongst which coinduction proof methods for language equality and language inclusion. At the same time, the present treatment of automata theory may serve as an introduction to coalgebra.
Partial Derivatives of Regular Expressions and Finite Automata Constructions
 Theoretical Computer Science
, 1995
"... . We introduce a notion of a partial derivative of a regular expression. It is a generalization to the nondeterministic case of the known notion of a derivative invented by Brzozowski. We give a constructive definition of partial derivatives, study their properties, and employ them to develop a new ..."
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Cited by 60 (0 self)
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. We introduce a notion of a partial derivative of a regular expression. It is a generalization to the nondeterministic case of the known notion of a derivative invented by Brzozowski. We give a constructive definition of partial derivatives, study their properties, and employ them to develop a new algorithm for turning regular expressions into relatively small NFA and to provide certain improvements to Brzozowski's algorithm constructing DFA. We report on a prototype implementation of our algorithm constructing NFA and present some examples. Introduction In 1964 Janusz Brzozowski introduced word derivatives of regular expressions and suggested an elegant algorithm turning a regular expression r into a deterministic finite automata (DFA); the main point of the algorithm is that the word derivatives of r serve as states of the resulting DFA [5]. In the following years derivatives were recognized as a quite useful and productive tool. Conway [8] uses derivatives to present various comp...
Motif Statistics
, 1999
"... We present a complete analysis of the statistics of number of occurrences of a regular expression pattern in a random text. This covers "motifs" widely used in computational biology. Our approach is based on: (i) a constructive approach to classical results in theoretical computer science ..."
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Cited by 46 (3 self)
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We present a complete analysis of the statistics of number of occurrences of a regular expression pattern in a random text. This covers "motifs" widely used in computational biology. Our approach is based on: (i) a constructive approach to classical results in theoretical computer science (automata and formal language theory), in particular, the rationality of generating functions of regular languages; (ii) analytic combinatorics that is used for deriving asymptotic properties from generating functions; (iii) computer algebra for determining generating functions explicitly, analysing generating functions and extracting coefficients efficiently. We provide constructions for overlapping or nonoverlapping matches of a regular expression. A companion implementation produces multivariate generating functions for the statistics under study. A fast computation of Taylor coefficients of the generating functions then yields exact values of the moments with typical application to random t...
NRgrep: A Fast and Flexible Pattern Matching Tool
 Software Practice and Experience (SPE
, 2000
"... We present nrgrep ("nondeterministic reverse grep"), a new pattern matching tool designed for efficient search of complex patterns. Unlike previous tools of the grep family, such as agrep and Gnu grep, nrgrep is based on a single and uniform concept: the bitparallel simulation of a non ..."
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Cited by 35 (7 self)
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We present nrgrep ("nondeterministic reverse grep"), a new pattern matching tool designed for efficient search of complex patterns. Unlike previous tools of the grep family, such as agrep and Gnu grep, nrgrep is based on a single and uniform concept: the bitparallel simulation of a nondeterministic suffix automaton. As a result, nrgrep can find from simple patterns to regular expressions, exactly or allowing errors in the matches, with an efficiency that degrades smoothly as the complexity of the searched pattern increases. Another concept fully integrated into nrgrep and that contributes to this smoothness is the selection of adequate subpatterns for fast scanning, which is also absent in many current tools. We show that the efficiency of nrgrep is similar to that of the fastest existing string matching tools for the simplest patterns, and by far unpaired for more complex patterns.
On Preventing Intrusions by Process Behavior Monitoring
 In Proceedings of the Workshop on Intrusion Detection and Network Monitoring. The USENIX Association
, 1999
"... Society's increasing reliance on networked information systems to support critical infrastructures has prompted interest in making the information systems survivable, so that they continue to perform critical functions even in the presence of vulnerabilities susceptible to malicious attacks. To ..."
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Cited by 32 (0 self)
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Society's increasing reliance on networked information systems to support critical infrastructures has prompted interest in making the information systems survivable, so that they continue to perform critical functions even in the presence of vulnerabilities susceptible to malicious attacks. To enable vulnerable systems to survive attacks, it is necessary to detect attacks and isolate failures resulting from attacks before they damage the system by impacting functionality, performance or security. The key research problems in this context include: . detecting inprogress attacks before they cause damage, as opposed to detecting attacks after they have succeeded, . localizing and/or minimizing damage by isolating attacked components in realtime, and . tracing the origin of attacks.