# Kleene's Three-Valued Logic

Requires a Wolfram Notebook System

Interact on desktop, mobile and cloud with the free Wolfram CDF Player or other Wolfram Language products.

Requires a Wolfram Notebook System

Edit on desktop, mobile and cloud with any Wolfram Language product.

This Demonstration presents a simple test for Kleene's three-valued logic. The values are: True, False, and Undefined (or Unknown or Undecided), with associated numerical values 1, 0, 1/2, respectively. The value of compound propositions is evaluated according to Kleene's truth tables.

[more]
Contributed by: Izidor Hafner (March 2011)

Based on work by: Jon Barwise and John Etchemendy

Open content licensed under CC BY-NC-SA

## Snapshots

## Details

J. Barwise and J. Etchemendy, *Tarski's World*, Stanford, CA: CSLI Publications, 1993.

J. Barwise and J. Etchemendy, *Hyperproof*, Stanford, CA: CSLI Publications, 1994, pp. 11–13.

S. C. Kleene, *Introduction to Matamathematics*, New York: Elsevier, 1952, pp. 332–335.

## Permanent Citation

"Kleene's Three-Valued Logic"

http://demonstrations.wolfram.com/KleenesThreeValuedLogic/

Wolfram Demonstrations Project

Published: March 7 2011