Categorically closed unipotent semigroups

Taras Banakh, Myroslava Vovk

Let $\mathcal{C}$ be a class of $T_1$ topological semigroups, containing all Hausdorff zero-dimensional topological semigroups. A semigroup $X$ is $\mathcal{C}$-$closed$ if $X$ is cl…