Filters








591,323 Hits in 4.6 sec

On the periodicity of regular languages

Kai Hwang
1979 Information and Control  
Canonical forms of the regular expressions representing such periodic languages are presented.  ...  We demonstrate a periodic formation of the grammatical production rules for periodic languages. The reducibility of periodic automata and languages is also studied.  ...  of F of all regular languages.  ... 
doi:10.1016/s0019-9958(79)90394-2 fatcat:bwafmd5vybhghm73zaoiktdfwu

Page 1063 of Mathematical Reviews Vol. , Issue 88b [page]

1988 Mathematical Reviews  
erty of the regular languages over a one-letter alphabet, and directly establish the ultimate periodicity of abelian regular languages over an arbitrary alphabet; furthermore, we discuss the relation  ...  We establish an inductive definition for abelian regular languages over an arbitrary alphabet based on ultimately periodic languages over a one-letter alphabet, generalize the ultimately periodic prop-  ... 

How to Prove that a Language Is Regular or Star-Free? [chapter]

Jean-Éric Pin
2020 Lecture Notes in Computer Science  
Most books of automata theory [9, 23, 29, 45, 49] offer exercises on regular languages, including some difficult ones.  ...  Another good source of tough questions is the recent book 200 Problems in Formal Languages and Automata Theory [36] . Surprisingly, there are very few exercises related to starfree languages.  ...  MSO[S] captures the class of regular languages. The second one relates first order logic and star-free languages. Theorem 19 (McNaughton [35]). FO[<] captures the class of star-free languages.  ... 
doi:10.1007/978-3-030-40608-0_5 fatcat:mzoyw7mckzgxnhyggsxiq4bhoa

Page 766 of Mathematical Reviews Vol. , Issue 80B [page]

1980 Mathematical Reviews  
s0b:08 oss Computer science (including automata) 166 Hwang, Kai 80b:68088 <jF} is defined to be the family of EOL forms generated by F, On the periodicity of regular languages.  ...  A systematic procedure to determine the periodicity of any given regular expression is devised through a differential approach. Closure properties of periodic languages are found.  ... 

On regularity of context-free languages

A. Ehrenfeucht, D. Haussler, G. Rozenberg
1983 Theoretical Computer Science  
In obtaining tlw latter results. we introduce the class of periodic languages. and demonstrate how they can bc uwd tr\ characterize the commutittl\e rt'gu_lar language>.  ...  the generated language is regular.  ...  Acknowledgment The authors are indebted to H.C.M. Kleijn and R. Verraedt for comments concerning the first draft of this paper. References  ... 
doi:10.1016/0304-3975(82)90124-4 fatcat:edt6tu22onat3j5nrlr77le67u

On subwords of infinite words

Lucian Ilie
1995 Discrete Applied Mathematics  
Some problems are left open there, one of them ' Research supported by Project I 128 I of the Academy of Finland.  ...  Several properties of infinite words are investigated in [3], especially for almost periodic ones, concerning subwords, prefixes, connections with languages in Chomsky hierarchy or Lindenmayer systems.  ...  As the language in the right-hand member of this equality is not regular and the family of regular languages is closed under intersection it follows that Sub, (WI) is not regular and the proof is completed  ... 
doi:10.1016/0166-218x(95)00063-1 fatcat:hco6dkmfzracxdg32f2jrfp7i4

REGULARIZATION IN THE CRYSTALLIZATION OF MODERN HEBREW: THE CASE OF COUNTERFACTUAL CONDITIONALS

Bar-Ziv Levy Miri
2021 Zenodo  
Regularization is a process of linguistic reduction through the elimination of variants. Regularization processes occur naturally during language acquisition and learning.  ...  A regularization process, which occurred mainly in the Mandate period, eliminated some variants, such as the positive meaning of ʾilmale and the qatal (regular past-tense) form in the main clause (the  ...  Regularization processes happen in all languages and periods, but there are situations where regularization brings about linguistic changes.  ... 
doi:10.5281/zenodo.5709214 fatcat:mps2u7wv7vbl3llmh3t4fu6dj4

A new characterization of the regular languages [chapter]

Christophe Reutenauer
1981 Lecture Notes in Computer Science  
Summar Z We define weakly commutative languages and periodic languages.We show that a language is regular if and only if it is simultaneously weakly commutative and periodic.  ...  R6sumg On d4fini% les notions de langage faiblement commutatif et de langage p6riodique.On montre qu'un langage est rationnel sl et seulement s'il est pgriodique et faiblement commutatif.  ...  ;the problem of finding conditions in which a periodic language is regular could be called the Burnside problem for languages.  ... 
doi:10.1007/3-540-10843-2_14 fatcat:c4wz53j4avge3opmtoy2ysji2y

Time Granularities and Ultimately Periodic Automata [chapter]

Davide Bresolin, Angelo Montanari, Gabriele Puppis
2004 Lecture Notes in Computer Science  
The relevance of the problem of managing periodic phenomena is widely recognized in the area of knowledge representation and reasoning.  ...  One of the most effective attempts at dealing with this problem has been the addition of a notion of time granularity to knowledge representation systems.  ...  From the closure properties of ω-regular languages, it follows that any ω-regular language L is uniquely identified by the set UP(L) of its ultimately periodic words, that is, for every pair of ω-regular  ... 
doi:10.1007/978-3-540-30227-8_43 fatcat:wtphljtfyreina5aqzdfniugd4

Automata, Boolean Matrices, and Ultimate Periodicity

Guo-Qiang Zhang
1999 Information and Computation  
A new characterization of such functions is derived in terms of the property of ultimate periodicity with respect to powers of Boolean matrices.  ...  This characterization reveals the intrinsic algebraic nature of regularity-preserving functions.  ...  Finally, thanks go to John Kececioglu for keeping the CATS seminar going; various versions of the paper were presented at the seminar.  ... 
doi:10.1006/inco.1998.2787 fatcat:7yrummiyivanhj6taiqaztpcxq

Primitive words and roots of words [article]

Gerhard Lischke
2011 arXiv   pre-print
Every nonempty word is a power of an uniquely determined primitive word which is called the root of the former one.  ...  We examine the powers of languages for different sets of exponents, and especially their regularity and context-freeness, in Section 5, and the decidability of appropriate questions in Section 6.  ...  to the anonymous referee for some hints.  ... 
arXiv:1104.4427v1 fatcat:5h6435drijg7vdy2bzw36leiqu

Learning Regular Omega Languages [chapter]

Dana Angluin, Dana Fisman
2014 Lecture Notes in Computer Science  
Three variations of the algorithm learn three different canonical representations of omega regular languages, using the notion of families of dfas.  ...  One is of size similar to L $ , a dfa representation recently learned using L * [7]. The second is based on the syntactic forc, introduced in [14]. The third is introduced herein.  ...  It follows from McNaughton's theorem [15] that two ω-regular languages are equivalent if they agree on the set of ultimately periodic words, justifying their use for representing examples.  ... 
doi:10.1007/978-3-319-11662-4_10 fatcat:bs5bugjxfrcobmua46l4ektxya

Learning regular omega languages

Dana Angluin, Dana Fisman
2016 Theoretical Computer Science  
Three variations of the algorithm learn three different canonical representations of omega regular languages, using the notion of families of dfas.  ...  One is of size similar to L $ , a dfa representation recently learned using L * [7]. The second is based on the syntactic forc, introduced in [14]. The third is introduced herein.  ...  It follows from McNaughton's theorem [15] that two ω-regular languages are equivalent if they agree on the set of ultimately periodic words, justifying their use for representing examples.  ... 
doi:10.1016/j.tcs.2016.07.031 fatcat:pqhjgq3cvnf7toewzmodnecnia

Libor Polák (1950–2020)

Jiří Kad'ourek, Ondřej Klíma
2021 Semigroup Forum  
The contribution from that period consists mainly in the introduction of some perspective concepts in the theory of regular languages.  ...  On algebraic theory of regular languages The first concept which Libor Polák invented in the theory of formal languages was the so-called syntactic semiring of a language.  ... 
doi:10.1007/s00233-021-10177-y fatcat:yqcyupmnmrcmrkl2q7npbptlmm

On the Complexity of Infinite Advice Strings

Gaëtan Douéneau-Tabot, Michael Wagner
2018 International Colloquium on Automata, Languages and Programming  
In our case, the model M is finite automata and the objects C are either recognized languages or presentable structures, known respectively as advice regular languages and advice automatic structures.  ...  Turing machines) and C a class of objects (e.g. languages), the complexity of an infinite word α can be measured with respect to the amount of objects from C that are presentable with machines from M using  ...  Basically, the ω-regularity feature is only used on suffixes of the advice. On the other hand, a automaton for Reg[α] is blind to the ω-future.  ... 
doi:10.4230/lipics.icalp.2018.122 dblp:conf/icalp/Doueneau-Tabot18 fatcat:73yhszegivf5njr53nv3d54jga
« Previous Showing results 1 — 15 out of 591,323 results