2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78922A necessary and sufficient condition for an oriented pretzel surface to be quasipositive yields an estimate for the slice genus of the boundary of an arbitrary oriented pretzel surface.6 pages, 8 figures; revised Feb. 22, 2000; to appear in Topology and its ApplicationsGeometric Topology57M25text