科研之友
微信
新浪微博
Facebook
分享链接
摘要
A'(kappa) asserts the existence of pairwise almost compatible finite-to-one functions A -> omega for each countable subset A of kappa. The existence of winning 2-Markov strategies in several infinite-length games, including the Menger game on the one-point Lindelofication kappa(dagger) of kappa, are guaranteed by A'(kappa). A'(kappa) is implied by the existence of cofinal Kurepa families of size kappa, and thus, holds for all cardinals less than N-omega. It is consistent that A'(N-omega) fails; however, there must always be a winning 2-Markov strategy for the second player in the Menger game on omega(dagger)(omega).
- 出版日期2018
