On rectangular covers of
On spaces with point-countable -systems
This paper deals with the behavior of -spaces, countably bi-quasi--spaces and singly bi-quasi--spaces with point-countable -systems. For example, we show that every -space with a point-countable -system is locally compact paracompact, and every separable singly bi-quasi--space with a point-countable -system has a countable -system. Also, we consider equivalent relations among spaces entried in Table 1 in Michael’s paper [15] when the spaces have point-countable -systems.
On subsets of Alexandroff duplicates
We characterize the subsets of the Alexandroff duplicate which have a G-diagonal and the subsets which are M-spaces in the sense of Morita.
On the metrizability of -spaces and its relationship to the normal Moore space conjecture
On Σ-products of Σ-spaces