Journal ArticleDOI
Flow languages equal recursively enumerable languages
Toshiro Araki,Nobuki Tokura +1 more
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It is shown that all recursively enumerable languages may be denoted by flow expressions, which contradicts A.C. Shaw's conjecture that the formal descriptive power of flow expressions lies somewhat below context-sensitive grammers.Abstract:
Recently, A.C. Shaw introduced a new class of expressions called flow expressions, and conjectured that the formal descriptive power of flow expressions lies somewhat below context-sensitive grammers. In this paper, we give a negative answer for his conjecture, that is, we show that all recursively enumerable languages may be denoted by flow expressions.read more
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Journal ArticleDOI
Algèbre de processus et synchronisation
Didier Austry,Gérard Boudol +1 more
TL;DR: Nous introduisons ici un calcul de processus fonde sur une composition parallele asynchrone, et quelques primitives de synchronisation, en particulier il s'avre equivalent au calcul synchrone de Milner (1980, 1983).
Journal ArticleDOI
Cecil: a sequencing constraint language for automatic static analysis generation
K.M. Olender,Leon J. Osterweil +1 more
TL;DR: A flexible and general mechanism for specifying problems relating to the sequencing of events and mechanically translating them into dataflow analysis algorithms capable of solving those problems is presented.
Journal ArticleDOI
Extending regular expressions with iterated shuffle
TL;DR: It is shown that every finite expression which uses the operations union, product, Kleene star, and iterated shuffle in any order defines a language which can be recognized non-deterministically by some multicounter machine in quasirealtime.
Journal ArticleDOI
Shuffle and scattered deletion closure of languages
TL;DR: The paper considers an operation dual to shue, namely scattered deletion: the scattered deletion of a word w from u consists of the words obtained by sparsely deleting from u the letters of w, in the order in which they appear in w.
Posted Content
Characterization and Complexity Results on Jumping Finite Automata
TL;DR: In this article, the authors characterize the corresponding class of languages in terms of special shuffle expressions and survey other equivalent notions from the existing literature, and present several results concerning computational hardness and algorithms for parsing and other basic tasks concerning jumping finite automata.
References
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Book
Computation: Finite and Infinite Machines
TL;DR: In this article, the authors present an abstract theory that categorically and systematically describes what all these machines can do and what they cannot do, giving sound theoretical or practical grounds for each judgment, and the abstract theory tells us in no uncertain terms that the machines' potential range is enormous and that its theoretical limitations are of the subtlest and most elusive sort.
Book ChapterDOI
The specification of process synchronization by path expressions
TL;DR: In this paper, a new method of expressing synchronization is presented and the motivations and considerations which led to this method are explained, and a means of automatically translating path expressions to existing primitive synchronization operations is given.
Journal ArticleDOI
Software Descriptions with Flow Expressions
TL;DR: Applications of flow expressions are exhibited in the modeling of concurrent programs, the description of operating system architectures, the specification and solution of synchronization problems, the flow and description of command languages, and in systems analysis and verification.
Proceedings ArticleDOI
Complexity of expressions allowing concurrency
TL;DR: The formal language shuffle operation is used to give an "algebraic" definition of semantics for a simple (structured) concurrent programming language and it is proved that the use of this operation is necessary.