I have been giving a problem were I have to design 1-bit subtractor, which performs single bit binary subtraction. It has three inputs: the digits ai, bi (bi is subtracted from ai) and the borrow from the previous 1-bit subtractor Bi-1. The outputs are Di (the difference) and the borrow Bi from the next 1-bit subtractor. Present all four stages (truth tables of the both functions, sum of products, minimization and logical circuits). During minimization follow the same approach that we used in class for 1-bit adder design.
I have search around, but I still cannot figure out how to approach this problem. If anyone could shed some light it would be greatly appreciated.