Logical Methods in Computer Science (Apr 2009)

The Church Problem for Countable Ordinals

  • Alexander Rabinovich

DOI
https://doi.org/10.2168/lmcs-5(2:5)2009
Journal volume & issue
Vol. Volume 5, Issue 2

Abstract

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A fundamental theorem of Buchi and Landweber shows that the Church synthesis problem is computable. Buchi and Landweber reduced the Church Problem to problems about ω-games and used the determinacy of such games as one of the main tools to show its computability. We consider a natural generalization of the Church problem to countable ordinals and investigate games of arbitrary countable length. We prove that determinacy and decidability parts of the Bu}chi and Landweber theorem hold for all countable ordinals and that its full extension holds for all ordinals < \omega\^\omega.

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