Which of the following is a functionally complete set of gates?

(i) NAND (ii) NOT

The Correct Answer is I but not II.

• NAND gate is a functionally complete set of gates.
• In the logic gate, a functionally complete collection of logical connectives or Boolean operators is one which can be used to express all possible truth tables by combining members of the set into a Boolean expression.
• A well-known complete set of connectors is {AND, NOT} and each of the singleton sets {NAND} is functionally complete, consisting of binary conjunction and negation.
• A NAND gate is a logic gate that generates a false output only if all its inputs are valid, so its output is complementary to that of an AND gate.
• A low output only results if all the inputs to the gate are high; a high output results if any input is low.

Key Points