Three-input universal logic gate

Logic gates are used to build computer chips. Reversible logic gates are of interest because they could in principle generate useful results for less heat generated (Landauer 1961). The nand gate is universal among irreversible logic gates, in the sense that it is possible to simulate any irreversible logic gate with a network of these gates. The Fredkin and Toffoli gates were the first gates to be proved universal among reversible logic gates. Read more