The SN74LS30 contains a single 8-input NAND gate. The output is LOW only when all eight inputs (A through H) are HIGH. If one or more inputs are LOW, the output is HIGH. This device performs the Boolean function Y = A·B·C·D·E·F·G·H̅ in positive logic, or equivalently Y = Ā + B̄ + C̄ + D̄ + Ē + F̄ + Ḡ + H̄ using De Morgan's theorem.