Lightface analytic game

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In descriptive set theory, a lightface analytic game is a game whose payoff set A is a \Sigma^1_1 subset of Baire space; that is, there is a tree T on \omega\times\omega which is a computable subset of (\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#.