In circuit terms, such a logic is a series connection of an OR gate with a NOT gate. In NOR logic, output "A" is "1" only if both inputs represent "0" at the same time. The output is "0" if at least one input is "1". The value table of the NOR gate corresponds to the inverted value table of the OR gate. Circuit families for NOR gates are the 7402 in TTL logic and 4001 in CMOS.