Solving Infinite Games in the Baire Space

arXiv (Cornell University)

Abstract

Infinite games (in the form of Gale-Stewart games) are studied where a play is a sequence of natural numbers chosen by two players in alternation, the winning condition being a subset of the Baire space $ω^ω$. We consider such games defined by a natural kind of parity automata over the alphabet $\mathbb{N}$, called $\mathbb{N}$-MSO-automata, where transitions are specified by monadic second-order formulas over the successor structure of the natural numbers. We show that the classical Büchi-Landweber Theorem (for finite-state games in the Cantor space $2^ω$) holds again for the present games: A game defined by a deterministic parity $\mathbb{N}$-MSO-automaton is determined, the winner can be computed, and an $\mathbb{N}$-MSO-transducer realizing a winning strategy for the winner can be constructed.

Authors 2

1. Benedikt Brütsch
2. Wolfgang Thomas Aachen Chair of Computer Science 7 (Logic and Theory of Discrete Systems) Chair of Computer Science

   RWTH Aachen University

   Affiliation as printed

   Chair of Computer Science 7 , RWTH Aachen University , Germany

   Chair of Computer Science RWTH Aachen University , Germany