2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/64142We introduce the notion of the Fourier and Fouier-Stieltjes algebra of a topological *-semigroup and show that these are commutative Banach algebras. For a class of foundation semigroups, we show that these are preduals of von Neumann algebras.19 pages, no figuresOperator Algebrastext