For m < n, any real analytic
m-submanifold of complex n-space with a nondegenerate CR singularity is shown to
be locally equivalent, under a holomorphic coordinate change, to a fixed real
algebraic variety defined by linear and quadratic polynomials. The situation is
analogous to Whitney’s stability theorem for cross-cap singularities of smooth maps.
The complex analyticity of the normalizing transformation is proved using a rapid
convergence argument.