  Under the hypotheses of smoothness of the interactions in the coupling
constant, locality, Poincare invariance, Lorentz covariance, and the
preservation of the number of derivatives on each field in the Lagrangian of
the interacting theory (the same number of derivatives like in the free
Lagrangian), we prove that the only consistent interactions in D=11 among
massless gravitini, a graviton, and a 3-form are described by N=1, D=11 SUGRA.
