R1 = 1
R2 = 2
R3 = 3
R4 = 4
R5 = 5
R6 = 6
R7 = 7

E1 = 10
E2 = 20
E3 = 30
E4 = 40

I1 = 1

A = [(R1+R2+R7) -R2 -R1;
	 -R2 (R2+R3+R4) -R3;
     -R1 -R5 (R1+R6+R5+R3)]
     
B = [(-E2*R7) (-E1*R1);
	 I1;
     (-E3*R5) (-E1*R6) E1*R1]