Rebol [ Title: "Calculate Pi" Date: 20-Jul-2003 File: %oneliner-pi.r Purpose: {Approximate PI with John Wallis formula. Precision limited to 15 digits due to REBOL. Just press ESC when fed up ;-) Formula from http:// www.chez.com/algor/math/pi.htm} One-liner-length: 83 Version: 1.0.0 Author: "Jean-Nicolas Merville" Library: [ level: 'beginner platform: none type: [How-to FAQ one-liner] domain: [math] tested-under: none support: none license: none see-also: none ] ] rebol[] s: 1 i: 0 forever [i: i + 2 s: s * (i / (i - 1) * i / (i + 1)) print 2 * S]