Displaying 301 – 320 of 948

Showing per page

Fixpoints, games and the difference hierarchy

Julian C. Bradfield (2003)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Drawing on an analogy with temporal fixpoint logic, we relate the arithmetic fixpoint definable sets to the winning positions of certain games, namely games whose winning conditions lie in the difference hierarchy over Σ 2 0 . This both provides a simple characterization of the fixpoint hierarchy, and refines existing results on the power of the game quantifier in descriptive set theory. We raise the problem of transfinite fixpoint hierarchies.

Fixpoints, games and the difference hierarchy

Julian C. Bradfield (2010)

RAIRO - Theoretical Informatics and Applications

Drawing on an analogy with temporal fixpoint logic, we relate the arithmetic fixpoint definable sets to the winning positions of certain games, namely games whose winning conditions lie in the difference hierarchy over Σ 2 0 . This both provides a simple characterization of the fixpoint hierarchy, and refines existing results on the power of the game quantifier in descriptive set theory. We raise the problem of transfinite fixpoint hierarchies.

Fonction ζ de Carlitz et automates

Valérie Berthé (1993)

Journal de théorie des nombres de Bordeaux

Carlitz a défini sur 𝔽 q une fonction ζ et une série formelle I I , analogues respectivement à la fonction ζ de Riemann et au réel π . Yu a montré, en utilisant les modules de Drinfeld, que ζ ( s ) / I I 3 est transcendant pour tout s non divisible par q - 1 . Nous donnons ici une preuve «automatique» de la transcendance de ζ ( s ) / I I 3 pour 1 s q - 2 , en utilisant le théorème de Christol, Kamae, Mendès France et Rauzy.

Forbidden factors and fragment assembly

F. Mignosi, A. Restivo, M. Sciortino (2001)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

In this paper methods and results related to the notion of minimal forbidden words are applied to the fragment assembly problem. The fragment assembly problem can be formulated, in its simplest form, as follows: reconstruct a word w from a given set I of substrings (fragments) of a word w . We introduce an hypothesis involving the set of fragments I and the maximal length m ( w ) of the minimal forbidden factors of w . Such hypothesis allows us to reconstruct uniquely the word w from the set I in linear...

Forbidden Factors and Fragment Assembly

F. Mignosi, A. Restivo, M. Sciortino (2010)

RAIRO - Theoretical Informatics and Applications

In this paper methods and results related to the notion of minimal forbidden words are applied to the fragment assembly problem. The fragment assembly problem can be formulated, in its simplest form, as follows: reconstruct a word w from a given set I of substrings (fragments) of a word w. We introduce an hypothesis involving the set of fragments I and the maximal length m(w) of the minimal forbidden factors of w. Such hypothesis allows us to reconstruct uniquely the word w from the set I in linear...

Foreword

V. Bruyère, M. Rigo (2010)

RAIRO - Theoretical Informatics and Applications

Formal language properties of hybrid systems with strong resets

Thomas Brihaye, Véronique Bruyère, Elaine Render (2010)

RAIRO - Theoretical Informatics and Applications

We study hybrid systems with strong resets from the perspective of formal language theory. We define a notion of hybrid regular expression and prove a Kleene-like theorem for hybrid systems. We also prove the closure of these systems under determinisation and complementation. Finally, we prove that the reachability problem is undecidable for synchronized products of hybrid systems.

Currently displaying 301 – 320 of 948