2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/59214Let H be a complex infinite dimensional Hilbert space. We describe the form of all *-semigroup endomorphisms $ϕ$ of B(H) which are uniformly continuous on every commutative C*-subalgebra. In particular, we obtain that if $ϕ$ satisfies $ϕ(0)=0$, then $ϕ$ is additive.7 pages. To appear in the Proceedings of the Memorial Conference for Bela Szokefalvi-Nagy, 1999, Szeged, HungaryOperator Algebrastext