2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/76412This is primarily an exposition, combining work of several authors (Curtis, Hsiang, Freedman, Stong, Matveyev, and Bizaca), of the proof that a smooth 5-dimensional h-cobordism between simply connected 4-manifolds is a product off of a contractible piece which itself is diffeomorphic to the 5-ball.11 pagesGeometric Topologytext