net2 example

R = [1 3 6 2];
I = [10 0];
G = [ sum(1./R(1:3)) -sum(1./R(2:3)); -sum(1./R(2:3)) sum(1./R(2:4))]
B = I';
V = G\B
G =

    1.5000   -0.5000
   -0.5000    1.0000


V =

    8.0000
    4.0000