The family of Łukasiewicz logics originated with the three-valued propositional logic introduced by Jan Łukasiewicz (1920). Its intermediate truth value
represented modal possibility. More
generally, for an integer
, the
-valued system has truth-value set
. Its negation
and implication operations are
|
(1)
| |||
|
(2)
|
A formula is a tautology when it has value 1 under every assignment of values in to its variables.
The infinite-valued Łukasiewicz logic uses the full interval with the same operations. The case
agrees with classical propositional calculus.