function dS=gtest14(x)
% Edgar & Himmelblau, 1988
% x0 = [-1, -2]'
% sem restricao:
% xo = [2, 1]'
% S(xo) = 0
% com restricao:
% xo = [0.8229, 0.9114]'
% S(xo) = 1.3935

dS = [(2*x(1)-4)  (2*x(2)-2)];
