On the solution of a problem of Okuyama
\textit{A. Okuyama} [Pac. J. Math. 42, 485-495 (1972; Zbl 0219.54018)] asked whether every perfect \(\Sigma^{\#}\)-space is a \(\Sigma\)-space. The author shows that every perfect strong \(\Sigma^{\#}\)-space is a strong \(\Sigma\)-space, which gives under MA\(+\neg CH\) a positive answer to the above question.
closed \(\sigma \)-conservative cover \(T_ 0\)-separating the points
scientific article; zbMATH DE number 3990343