function S=test(x)
% problema dos extratores em série
% x0 = [0.019 0.018]
% xo = [0.0135 0.0092]
% S(xo) = -19.4588

a=129.98;
b=4000;
c=0.5;
d=25;

L=a-b*x(2)-c./x(1)-d*x(1)./x(2);
S=-L;

% [xo,So,nS] = complex('test21',[0.019, 0.018],1,[1e-3 1e-3],[0.02 0.02],[],[],[],0.001)
