2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61685We prove a Nash-Moser type inverse function theorem in Frechet spaces for functions with approximate inverses, allowing for a loss of derivatives proportional to $n$ in the way of Lojasiewicz and Zehnder.11 pagesFunctional AnalysisDynamical Systems58C15text