If X and Y are the inputs, the given circuit works as _______.

Step-by-step solution

The circuit consists of four NAND gates. The first two NAND gates have their inputs tied together, acting as NOT gates. Their outputs are X and Y . These outputs are fed into the third NAND gate. The output of this gate is: y' = X Y Using De Morgan's theorem: y' = X + Y = X + Y This output is fed into the fourth NAND gate, which also has its inputs tied together, acting as a NOT gate. The final output is: Output = X + Y This represents the Boolean expression for a NOR gate. Answer: NOR gate