“…9) where xl, xi, x: is the ith training example, dt is the corresponding desired output, for i = 1, 2, 3, 4, 5 and w,,, w,,, w,,, w,, are the connected weight values between the input cells and the output cells. Since, if the rank r of the coefficient matrix X is equal to the rank r' of augmented matrix [XI Y], there exists a solution (Hoffman and Kunze 1971, Albert 1972, Lorentz 1976, Sprecher 1965, Werbis 1974, i.e. there is a solution for the connected weight matrix W. We know that expression (3), consisting of five linear equations in four unknown variables, may not be solved.…”