Codes and infinite words
Codes can be characterized by their way of acting on infinite words. Three kinds of characterizations are obtained. The first characterization is related to the uniqueness of the factorization of particular periodic words. The second characterization concerns the rational form of the factorizations...
Saved in:
Main Authors: | |
---|---|
Format: | Article |
Published: |
1994
|
Series: | Acta cybernetica
11 No. 4 |
Kulcsszavak: | Számítástechnika, Kibernetika |
Subjects: | |
Online Access: | http://acta.bibl.u-szeged.hu/12532 |
Summary: | Codes can be characterized by their way of acting on infinite words. Three kinds of characterizations are obtained. The first characterization is related to the uniqueness of the factorization of particular periodic words. The second characterization concerns the rational form of the factorizations of rational words. The third characteristic fact is the finiteness of the number of factorizations of the rational infinite words. A classification of codes based on the number of factorizations for different kinds of infinite words is set up. The obtained classes are compared with thé class of u-codes, the class of weakly prefix codes and the class of codes with finite deciphering delay. Complementary results are obtained in the rational case, for example a necessary and sufficient condition for a rational w-code to have a bounded deciphering delay is given. Risumé: La factorisation des mots infinis permet de caractériser les codes parmi les langages de mots finis. Les critères obtenus sont de trois types. Le premier critère est relatif à l'unicité de la factorisation de certains mots périodiques. Le second concerne la forme des factorisations des mots rationnels. Finalement, seuls les codes-nous assurent de la finitude du nombre de factorisations des mots rationnels. Les codes sont classifiés selon le nombre de factorisations de certains types de mots infinis. Les classes obtenues sont étudiées et comparées avec les classes déjà définies de v-codes, de codes faiblement préfixes et de codes à délai borné. Des résultats complémentaires sont obtenus dans le cas rationnel, en particulier il est donné une condition nécessaire et suffisante pour qu'un tu-code rationnel soit à délai borné. |
---|---|
Physical Description: | 241-256 |
ISSN: | 0324-721X |