Box and Nabla Products that are D-Spaces

Hector A. Barriga-Acosta, Paul M. Gartside

A space $X$ is $D$ if for every assignment, $U$, of an open neighborhood to each point $x$ in $X$ there is a closed discrete $D$ such that $\bigcup \{U(x):x\in D\}=X$. The box p…