2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/121809The calculus of variations for lagrangians which are not functions on the tangent bundle, but sections certain affine bundles is developed. We follow a general approach to variational principles which admits boundary terms of variations.9 pages, XV International Workshop on Geometry and Physics, Tenerife 2006Mathematical PhysicsDifferential Geometry70G45, 70H03, 70H05text