Cofinal类型如下

The Journal of Symbolic Logic Pub Date : 2023-07-24 DOI:10.1017/jsl.2023.32

ROY SHALEV

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引用次数: 1

摘要

证明了对于每一个正整数n，基数$\leq \aleph _n$的非tukey等价有向集的个数至少为$c_{n+2}$，即$(n+2)$ -加泰罗尼亚数。此外，基数$\leq \aleph _n$的有向集的$\mathcal D_{\aleph _n}$类包含Dyck $(n+2)$ -paths的偏置集的同构副本。此外，我们给出了副本中两个连续元素之间是否包含另一个有向集的完整描述。

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