| Identifiant de l'article : |
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ensl-00216624, version 1 |
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| Identifiant arXiv : |
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arXiv:0801.3912 |
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| Domaine : |
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| Titre : |
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On the Continuity Set of an omega Rational Function |
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| Auteur(s) : |
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Olivier Carton1, Olivier Finkel2, Pierre Simonnet3 |
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| Laboratoire : |
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| 1 : |
LIAFA - Laboratoire d'informatique Algorithmique : Fondements et Applications |
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LIP - Laboratoire de l'Informatique du Parallélisme |
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SPE - Sciences pour l'environnement |
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| Équipe de recherche : |
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[MC2 - Modèles de calcul et complexité] |
| Résumé : |
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In this paper, we study the continuity of rational functions realized by Büchi finite state transducers. It has been shown by Prieur that it can be decided whether such a function is continuous. We prove here that surprisingly, it cannot be decided whether such a function F has at least one point of continuity and that its continuity set C(F) cannot be computed. In the case of a synchronous rational function, we show that its continuity set is rational and that it can be computed. Furthermore we prove that any rational Pi^0_2-subset of X^omega for some alphabet X is the continuity set C(F) of an omega-rational synchronous function F defined on X^omega. |
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Langue du texte intégral : |
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Anglais |
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| Mots-clés : |
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Infinitary rational relations – Omega rational functions – Topology – Points of continuity – Decision problems – Omega rational languages – Omega context-free languages |
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| Commentaire : |
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Dedicated to Serge Grigorieff on the occasion of his 60th Birthday |
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