2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/62205It is proved that there is no structure of left (right) cancelative semigroup on $[L]$-dimensional universal space for the class of separable compact spaces of extensional dimension $\le [L]$. Besides, we note that the homeomorphism group of $[L]$-dimensional space whose nonempty open sets are universal for the class of separable compact spaces of extensional dimension $\le [L]$ is totally disconnected.General Topology54H15Topological semigroups and universal spaces related to extension dimensiontext