Lightface analytic game

Game whose payoff set A is a subset of Baire space

In descriptive set theory, a lightface analytic game is a game whose payoff set A is a Σ 1 1 {\displaystyle \Sigma _{1}^{1}} subset of Baire space; that is, there is a tree T on ω × ω {\displaystyle \omega \times \omega } which is a computable subset of ( ω × ω ) < ω {\displaystyle (\omega \times \omega )^{<\omega }} , such that A is the projection of the set of all branches of T.

The determinacy of all lightface analytic games is equivalent to the existence of 0#.


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