Uniqueness of the Seiberg-Witten Effective Lagrangian
  The low energy effective Lagrangian for $N\es 2$ supersymmetric Yang-Mills theory, proposed by Seiberg and Witten is shown to be the unique solution, assuming only that supersymmetry is unbroken and that the number of strong-coupling singularities is finite. Duality is then a consequence rather than an input. 
R. Flume, M. Magro, L.O'Raifeartaigh, I. Sachs, O. Schnetz