Top-designs in the category of Fort spaces

Abstract

In infinite topological Fort space $X$, for nonempty subsets $C,D$ of $X$ in the following text we answer to this question "Is there any $\lambda$ and Top--design $C-(X,D,\lambda)$ of type $i$?" for $i=1,2,3,4$. We prove there exist $\lambda$ and $C-(X,D,\lambda)$, Top--design of type 2 (resp. type 4) if and only if $C$ can be embedded into $D$.