论文标题
高$f_σ$高的分析理想
Tall $F_σ$ subideals of tall analytic ideals
论文作者
论文摘要
回答一个hrušák的问题,我们表明$ω$上的每个分析高理想都包含$f_σ$高的理想。我们还举例说明没有Borel选择器的$F_σ$高理想。
Answering a question of Hrušák, we show that every analytic tall ideal on $ω$ contains an $F_σ$ tall ideal. We also give an example of an $F_σ$ tall ideal without a Borel selector.