  For a Fedosov manifold (symplectic manifold equipped with a symplectic
torsion-free affine connection $\nabla$) admitting a metaplectic structure, we
shall investigate two sequences of first order differential operators acting on
sections of certain bundles over this manifold. The operators are symplectic
analogues of the twistor operators known from Riemannian spin geometry.
Therefore we call the mentioned sequences symplectic twistor sequences. These
sequences are complexes if the connection $\nabla$ is of Ricci type. We shall
prove that the so called truncated parts of these complexes are elliptic. This
establishes a background for a future analytic study.
