Truth value

In logic and mathematics, a logical value, also called a truth value, is a value indicating the extent to which a proposition is true.In classical logic, the only possible truth values are true and false.However, other values are possible in other logics:
fuzzy logic and other forms of multi-valued logic use more truth values than simply true and false.

Algebraically, the set {true, false} forms a two-element Boolean algebra. Other kinds of algebras may be used as sets of truth values in non-classical logics: for instance, intuitionistic logic uses Heyting algebras.

In topos theory, the subobject classifier of a topos takes the place of the set of truth values.

* The truth value of a proposition is shown using 0s and 1s.:True = 1:False = 0

ee also

* Boolean domain
* Degrees of truth
* False dilemma
* Fuzzy logic
* Logical connective
* Multivalued logic
* Relativism
* Slingshot argument
* Negation

External links

* [http://plato.stanford.edu/entries/logical-constants/ Article on logical constants] at the Stanford Encyclopedia of Philosophy

* [http://math.andrej.com/2005/05/16/how-many-is-two/ Weblog entry "How many is two?"] by Andrej Bauer discussing the relationship between truth values in intuitionistic logic and topos theory on the one hand and classical logic on the other.