TheD-Property of Finite Unions oft-Metrizable Spaces and Certain Function Spaces

摘要

The additivity ofD-property is studied ont-metrizable spaces andcertain function spaces. It is shown that a space of countable tightness is aD-spaceprovided that it is the union of finitely manyt-metrizable subspaces, or function spacesCp(Xi)where eachXiis LindelöfΣ.