加载中…
On page 43 in \cite{Po83} Sorin Popa asked whether the following property holds: \emph{If is a free ultrafilter on and $\mathcal R_1\subseteq \mathcal R_1\mathcal R’\cap \mathcal R^\omega\subseteq \mathcal R^\omega_1\mathcal R_1=\mathcal R$?} In this short note we provide an affirmative answer to this question.

生成讲解博客的中文版本

生成AI智能校验的中文版本