4-bit large/small comparator

4-bit large/small comparator using relays. (Calculator Components) Left bulb = Outputs the sign of A+B (0=+/1=-) Center bulb = Outputs 1 when A>B Right bulb = Outputs 1 when B>A A± (0=+/1=-) A0 A1 A2 A2 B± (0=+/1=-) B0 B1 B2 B3