function S=test(x)
% Edgar & Himmelblau, 1988
% x0 = [1, 0]'
% xo = [0.5, -1]'
% S(xo) = 0 (local minimum)

S= exp(x(1)) * (4*x(1)^2  + 2*x(2)^2  + 4*x(1)*x(2) + 2*x(2) + 1);
