In
logic, a
three-valued logic (also
trinary logic,
trivalent,
ternary, or
trilean, sometimes abbreviated
3VL) is any of several
many-valued logic systems in which there are three
truth values indicating
true,
false and some indeterminate third value. This is contrasted with the more commonly known
bivalent logics (such as classical sentential or
Boolean logic) which provide only for
true and
false. Conceptual form and basic ideas were initially created by
Jan Lukasiewicz and
C. I. Lewis. These were then re-formulated by
Grigore Moisil in an axiomatic algebraic form, and also extended to
n-valued logics in 1945.