2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/78193Using techniques developed in the revision theory of truth, I build a model for the set theory NF (New Foundations) developed by Quine in ZF, therefore proving its consistency relative to ZF. The model is essentially a term model; the sets of NF are interpreted as equivalence classes of closed stratified terms of a language that is a slight modification of that of NF.The article has been withdrawn since a possible error was pointed out in the proof of the first crucial theoremLogic03E35 (Primary) 03C62,04E70 (Secondary)text