  We show that the possible ensembles produced when a separable operation acts
on a single pure bipartite entangled state are completely characterized by a
majorization condition, a collection of inequalities for Schmidt coefficients,
which is identical to that already known for the particular case of local
operations and classical communication (LOCC). As a consequence, various known
results for LOCC, including some involving monotonicity of entanglement, can be
extended to the class of all separable operations.
