  Let \Sigma be a minimal submanifold of \R^{n+m} that can be represented as
the graph of a smooth map f:\R^n-->\R^m. We apply a formula we derived in the
study of mean curvature flow to obtain conditions under which \Sigma must be an
affine subspace. Our result covers all known ones in the general case. The
conditions are stated in terms of the singular values of $df$.
