theorem Th75:
  1-Veblen(a) is epsilon
  proof set U = Tarski-Class(a\/omega);
    0-Veblen(1-Veblen a) = (succ 0)-Veblen a by Th69;
    hence exp(omega,1-Veblen a) = 1-Veblen a by Th68;
  end;
