2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/143990We show that every closed L_infty,loc - form on R^n is exact. Differential is understood in the sense of currents. The proof does not use any explicit geometric constructions. De Rham theorem follows.6 pagesDifferential GeometryFunctional Analysis58A12, 53C65 (Primary); 46E35, 55N99 (Secondary)text