2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/202554We construct a realistic SU(7) model which provides answers to many questions presently facing the prototype SU(5) SUSY GUT. Among them are a solution to the doublet-triplet splitting problem, string scale unification, proton decay, the hierarchy of baryon vs lepton number violation and neutrino masses.30 pages, latex, 2 postscript figures; slightly modified version (misprints corrected and references added) submitted to Nuclear Physics BHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext