On the Alster, Menger and D-type covering properties

Osipov A., ÖZÇAĞ S.

QUAESTIONES MATHEMATICAE, 2019 (SCI-Expanded) identifier identifier


In this paper we give new characterizations for almost Menger and weakly Menger spaces by neighborhood assignments and define a natural weakening of almost D-spaces and weakly D-spaces. We discuss the relationships among the properties "D-type", "Menger", "Alster", and the weak versions of these properties in Lindelof spaces.