Английская Википедия:AD+
Материал из Онлайн справочника
In set theory, AD+ is an extension, proposed by W. Hugh Woodin, to the axiom of determinacy. The axiom, which is to be understood in the context of ZF plus DC<math>\mathbb{R}</math> (the axiom of dependent choice for real numbers), states two things:
- Every set of reals is ∞-Borel.
- For any ordinal λ less than Θ, any subset A of ωω, and any continuous function π:λω→ωω, the preimage π−1[A] is determined. (Here λω is to be given the product topology, starting with the discrete topology on λ.)
The second clause by itself is referred to as ordinal determinacy.
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