For this question, please refer to Chapter 33 page 638, Set Theory Millennium Edition, by Thomas Jech.
The proof of analytic games GA is converted into an open game Gast on some suitable space. In the game Gast, Player I plays a0, then Player II plays a pair (b0,h0), then I plays a1, followed by II playing (b1,h1), and so on. Each hi is an order preserving function from Ki into kappa (refer to the text for the definition of Ki). If Player II is able to construct the h's such that hi+1 extends hi for each iinomega, then Player II wins. This game Gast, as mentioned, is an open game.
I would like to know specifically what the payoff set is and what the space is (including the topology).
I came up with the following:
The space is kappaK, where K=bigcupssubseteqxKs, x=langlea0,b0,ldotsrangle formed at the end of the run, and the topology is just like that of the Baire space. The payoff set in Gast is Aast=finkappaK:f;textisnotorderpreserving. This set is closed by showing that the complement is open (easy). Hence, the game Gast is an open/closed game.
The above seem plausible, but the issue I have with the set I came up with is
it doesn't look like a set that include a "pair" as in (b0,h0), for instance, does not appear anywhere, and
the set K is particular to the x=langlea0,b0,ldotsrangle produced.
I would appreciate if you could let me know if the above is right and provide me a hint as to how to relate to the related notion of a homogeneous tree thereafter. If the above doesn't makes sense, please let me know where it went wrong and a hint as to how to get the right open set in what topological space would be nice.
Thanks!
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