function y = f(x)
    y = [x(1)^2 - x(2); 
        -x(1)   + x(2)^2];
endfunction
//
function y = d1f(x)
    y = [2*x(1),  -1; 
           -1  , 2*x(2)];
endfunction
//
//x0 = [0.1; 0.2];
x0 = [0.8; 0.7];
E = 1d-5;
kmax = 20;
//
[z,v,info,StimaErr,succ] = newtonNd(f,x0,d1f,E,kmax);z
//
clf();
plot(succ(1,:),succ(2,:));
xgrid();
