On 11/14/2011 05:57 AM, Marc Heiler wrote: > require "prime" > > > ^^^ Is this specific to Ruby 1.9.x ? There's a Prime class that's available if you require 'mathn' -- Darryl L. Pierce <mcpierce / gmail.com> http://mcpierce.multiply.com/ "What do you care what people think, Mr. Feynman?"