论文标题
算是完美的微薄套装
Countably perfectly meager sets
论文作者
论文摘要
我们研究了一个完美的微薄集合的概念的加强。 我们说，如果每一个完美的子集$ \ \ {p_n：n \ in {\ mathbb n} $ x $的$ x $ $ x $ $ x $，一个$ a $ a $ a $ a $在$ x $中都非常微薄，如果$ x $ $ \ {p_n：n \ in { $ p_n $每$ n $。 我们给出了各种特征和示例，这些示例非常微薄。我们证明，并非每个普遍的微薄套件都可以完全微不足道，从而纠正了Bartoszyński的早期结果。
We study a strengthening of the notion of a perfectly meager set. We say that that a subset $A$ of a perfect Polish space $X$ is countably perfectly meager in $X$, if for every sequence of perfect subsets $\{P_n: n \in {\mathbb N}\}$ of $X$, there exists an $F_σ$-set $F$ in $X$ such that $A \subseteq F$ and $F\cap P_n$ is meager in $P_n$ for each $n$. We give various characterizations and examples of countably perfectly meager sets. We prove that not every universally meager set is countably perfectly meager correcting an earlier result of Bartoszyński.
