A Full-Substractor Is a Combinational Circuit That Performs a Substraction between two bits, taking into account that a 1 may have been borrowed by a lower significant stage.

The Circuit Has 3 inputs and two outputs. The three inputs, X,Y,and Z, denote the minuend, substrahend, and previous borrow, respectively.

The two outputs, D and B, represent the difference and output borrow, respesctively.