First countable and almost discretely Lindelöf $T_3$ spaces have cardinality at most continuum

István Juhász, Lajos Soukup, Zoltán Szentmiklóssy

A topological space $X$ is called almost discretely Lindelöf if every discrete set $D\subset X$ is included in a Lindelöf subspace of $X$. We say that the space $X$ is {\em $\mu$-se…