论文标题
$π$ - 空格及其开放图像
$π$-spaces and their open images
论文作者
论文摘要
我们研究可以通过连续的准打开的两次试验映射到Baire空间（即可数离散空间的可数功率）上的空间。我们从Souslin方案中给出了此类空间的表征，并将这些空间称为$π$ - 空格。我们表明，每个具有lusin $π$ bas的空间都是$π$ - 空间，并且每个第二个可计可数的$π$ -space都有lusin $π$ - 基本。本文的主要结果是$π$空间的连续开放图像的表征。
We study spaces that can be mapped onto the Baire space (i.e. the countable power of the countable discrete space) by a continuous quasi-open bijection. We give a characterization of such spaces in terms of Souslin schemes and call these spaces $π$-spaces. We show that every space that has a Lusin $π$-base is a $π$-space and that every second-countable $π$-space has a Lusin $π$-base. The main result of this paper is a characterization of continuous open images of $π$-space.
