  We introduce and completely describe the analogues of the Riemann curvature
tensor for the curved supergrassmannian of the passing through the origin
(0|2)-dimensional subsupermanifolds in the (0|4)-dimensional supermanifold with
the preserved volume form. The underlying manifold of this supergrassmannian is
the conventional Penrose's complexified and compactified version of the
Minkowski space, i.e., the Grassmannian of 2-dimensional subspaces in the
4-dimensional space. The result provides with yet another counterexample to
Coleman-Mandula's theorem.
