# Many-valued Logic | | **Many-valued Logic** is a propositional calculus in which there are more than two truth values. Traditionally, in Aristotle's logical calculus, there were only two possible values for any proposition. Classical two-valued logic may be extended to n-valued logic for n greater than 2. Those most popular in the literature are three-valued, four-valued, nine-valued, the finite-valued with more than three values, and the infinite-valued (infinitely-many-valued), such as fuzzy logic and probability logic. | |-|-| | | wikipedia:: [Many-valued logic](https://en.wikipedia.org/wiki/Many-valued_logic) |