2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/69340In this paper we deal with linear systems of P^3 through fat points. We consider the behavior of these systems under a cubo-cubic Cremona transformation that allows us to produce a class of special systems which we conjecture to be the only ones.16 Pages, LaTeXAlgebraic Geometry14C20text