From his paradise that Cantor with us unfolded,we hold our breath in awe;knowing,we shall not be expelled. David Hilbert 没有人能把我们从Cantor创造的乐园中驱逐出去” 4口·￥①，43，t夏，里Q0 Hengeng Wei thkweionjn.edu.cn 1-11 Set Theory (IV):Infinity 2019 1217 4/49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . From his paradise that Cantor with us unfolded, we hold our breath in awe; knowing, we shall not be expelled. — David Hilbert “没有人能把我们从 Cantor 创造的乐园中驱逐出去” Hengfeng Wei (hfwei@nju.edu.cn) 1-11 Set Theory (IV): Infinity 2019 年 12 月 17 日 4 / 49