2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/219841The norm closure of the algebra generated by the set $\{n\mapsto λ^{n^k}:$ $λ\in{\mathbb {T}}$ and $k\in{\mathbb{N}}\}$ of functions on $({\mathbb {Z}}, +)$ was studied in \cite{S} (and was named as the Weyl algebra). In this paper, by a fruitful result of Namioka, this algebra is generalized for a general semitopological semigroup and, among other things, it is shown that the elements of the involved algebra are distal. In particular, we examine this algebra for $({\mathbb {Z}}, +)$ and (more generally) for the discrete (additive) group of any countable ring. Finally, our results are treated for a bicyclic semigroup.To appear in Methods Funct. Anal. TopologyFunctional Analysis54H20; 54C35; 43A60text