2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/190311We discuss a number of lattice fermion actions solving the Ginsparg-Wilson relation. We also consider short ranged approximate solutions. In particular, we are interested in reducing the lattice artifacts, while avoiding (or suppressing) additive mass renormalization. In this context, we also arrive at a formulation of improved domain wall fermions.20 pages LaTex, 3 double figures, 4 tables, final version to appear in Eur. Phys. J. CHigh Energy Physics - Latticetext