Computer Science
Logical operators are implemented as logic gates in digital circuits. Practically all digital circuits (the major exception is DRAM) are built up from NAND, NOR, NOT, and transmission gates. NAND and NOR gates with 3 or more inputs rather than the usual 2 inputs are fairly common, although they are logically equivalent to a cascade of 2-input gates. All other operators are implemented by breaking them down into a logically equivalent combination of 2 or more of the above logic gates.
The "logical equivalence" of "NAND alone", "NOR alone", and "NOT and AND" is similar to Turing equivalence.
That fact that all truth functions can be expressed with NOR alone is demonstrated by the Apollo guidance computer.
Read more about this topic: Truth Function
Famous quotes containing the words computer and/or science:
“Family life is not a computer program that runs on its own; it needs continual input from everyone.”
—Neil Kurshan (20th century)
“Art is the beautiful way of doing things. Science is the effective way of doing things. Business is the economic way of doing things.”
—Elbert Hubbard (1856–1915)