A Tukey decomposition of κλ and the tree
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Masayuki Karato
📂
Article
📅
2005
🏛
John Wiley and Sons
🌐
English
⚖ 147 KB
Generalizing a result of Todorčević, we prove the existence of directed sets D, E such that D ≥ Pκλ and E ≥ Pκλ but D × E ≥ Pκλ in the Tukey ordering. As an application, we show that the tree property for directed sets introduced by Hinnion is not preserved under products.