What is the expression spoken for a NAND gate?

The expression for a NAND gate is accurately described as "X AND Y quantity NOT." This means that the output of a NAND gate is the negation of the AND operation applied to its inputs, X and Y. In Boolean algebra, the AND operation results in true only when both inputs are true. However, a NAND gate inverts this condition: its output is false only when both inputs are true, and it produces true for all other combinations of inputs.

To clarify, when both X and Y are true (1), the output of the NAND gate is false (0), which is the opposite of what an AND gate would produce. For all other input combinations—where at least one of the inputs is false (0)—the NAND gate outputs true (1). Thus, the correct expression captures the fundamental behavior of the NAND gate accurately, making it essential in digital logic design as a universal gate for constructing other logic functions.