2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/118162We give the first example of a quartically hyponormal unilateral weighted shift which is not 3-hyponormal.Functional AnalysisOperator Algebras47B20; 47B37; 47A13Quartically hyponormal weighted shifts need not be 3-hyponormaltext