Natural operators lifting vector fields to bundles of Weil contact elements
Let be a Weil algebra. The bijection between all natural operators lifting vector fields from -manifolds to the bundle functor of Weil contact elements and the subalgebra of fixed elements of the Weil algebra is determined and the bijection between all natural affinors on and is deduced. Furthermore, the rigidity of the functor is proved. Requisite results about the structure of are obtained by a purely algebraic approach, namely the existence of nontrivial is discussed.