 Axiom of determinacy

The axiom of determinacy states that every game $G(A)$ with $A\subseteq {\omega }^{\omega }$ is determined. Its version for a move set $M$ is denoted ${\mathsf{AD}}_M$.

The Axiom of Determinacy (AD) is a principle in set theory that relates to the behavior of certain games and the existence of winning strategies in those games. More specifically, the Axiom of Determinacy posits that for certain kinds of infinite games involving two players, one player can always have a winning strategy.