2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/131021We compute formal invariants associated with the cohomology sheaves of the direct image of holonomic D-modules of exponential type. We also prove that every formal C[[t]]<\partial_t>-modules is isomorphic, after a ramification, to a germ of formalized direct image of analytic D-module of exponential type.19 pages, 5 figures, supported by a fellowship of the Deutsche Forschungsgemeinschaft. Revised versionAlgebraic GeometryComplex Variables32S40; 32C38; 34M35text