Displaying 21 – 40 of 186

Showing per page

An automata-theoretic approach to the study of the intersection of two submonoids of a free monoid

Laura Giambruno, Antonio Restivo (2008)

RAIRO - Theoretical Informatics and Applications

We investigate the intersection of two finitely generated submonoids of the free monoid on a finite alphabet. To this purpose, we consider automata that recognize such submonoids and we study the product automata recognizing their intersection. By using automata methods we obtain a new proof of a result of Karhumäki on the characterization of the intersection of two submonoids of rank two, in the case of prefix (or suffix) generators. In a more general setting, for an arbitrary number of generators,...

Automates et algébricités

Jean-Paul Allouche (2005)

Journal de Théorie des Nombres de Bordeaux

Dans quelle mesure la régularité des chiffres d’un nombre réel dans une base entière, celle des quotients partiels du développement en fraction continuée d’un nombre réel, ou celle des coefficients d’une série formelle sont-elles liées à l’algébricité ou à la transcendance de ce réel ou de cette série formelle  ? Nous proposons un survol de résultats récents dans le cas où la régularité évoquée ci-dessus est celle de suites automatiques, substitutives, ou sturmiennes.

Axiomatizing omega and omega-op powers of words

Stephen L. Bloom, Zoltán Ésik (2004)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

In 1978, Courcelle asked for a complete set of axioms and rules for the equational theory of (discrete regular) words equipped with the operations of product, omega power and omega-op power. In this paper we find a simple set of equations and prove they are complete. Moreover, we show that the equational theory is decidable in polynomial time.

Axiomatizing omega and omega-op powers of words

Stephen L. Bloom, Zoltán Ésik (2010)

RAIRO - Theoretical Informatics and Applications

In 1978, Courcelle asked for a complete set of axioms and rules for the equational theory of (discrete regular) words equipped with the operations of product, omega power and omega-op power. In this paper we find a simple set of equations and prove they are complete. Moreover, we show that the equational theory is decidable in polynomial time.

Binary patterns in binary cube-free words: Avoidability and growth

Robert Mercaş, Pascal Ochem, Alexey V. Samsonov, Arseny M. Shur (2014)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

The avoidability of binary patterns by binary cube-free words is investigated and the exact bound between unavoidable and avoidable patterns is found. All avoidable patterns are shown to be D0L-avoidable. For avoidable patterns, the growth rates of the avoiding languages are studied. All such languages, except for the overlap-free language, are proved to have exponential growth. The exact growth rates of languages avoiding minimal avoidable patterns are approximated through computer-assisted upper...

Circular splicing and regularity

Paola Bonizzoni, Clelia De Felice, Giancarlo Mauri, Rosalba Zizza (2004)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Circular splicing has been very recently introduced to model a specific recombinant behaviour of circular DNA, continuing the investigation initiated with linear splicing. In this paper we restrict our study to the relationship between regular circular languages and languages generated by finite circular splicing systems and provide some results towards a characterization of the intersection between these two classes. We consider the class of languages X * , called here star languages, which are closed...

Circular splicing and regularity

Paola Bonizzoni, Clelia De Felice, Giancarlo Mauri, Rosalba Zizza (2010)

RAIRO - Theoretical Informatics and Applications

Circular splicing has been very recently introduced to model a specific recombinant behaviour of circular DNA, continuing the investigation initiated with linear splicing. In this paper we restrict our study to the relationship between regular circular languages and languages generated by finite circular splicing systems and provide some results towards a characterization of the intersection between these two classes. We consider the class of languages X*, called here star languages, which are closed...

Classes of two-dimensional languages and recognizability conditions

Marcella Anselmo, Maria Madonia (2010)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

The paper deals with some classes of two-dimensional recognizable languages of “high complexity”, in a sense specified in the paper and motivated by some necessary conditions holding for recognizable and unambiguous languages. For such classes we can solve some open questions related to unambiguity, finite ambiguity and complementation. Then we reformulate a necessary condition for recognizability stated by Matz, introducing a new complexity function. We solve an open question proposed by Matz,...

Classes of two-dimensional languages and recognizability conditions

Marcella Anselmo, Maria Madonia (2011)

RAIRO - Theoretical Informatics and Applications

The paper deals with some classes of two-dimensional recognizable languages of “high complexity”, in a sense specified in the paper and motivated by some necessary conditions holding for recognizable and unambiguous languages. For such classes we can solve some open questions related to unambiguity, finite ambiguity and complementation. Then we reformulate a necessary condition for recognizability stated by Matz, introducing a new complexity function. We solve an open question proposed by Matz,...

Currently displaying 21 – 40 of 186