README.md

See https://www.youtube.com/watch?v=4_RJu_TrqO0&feature=youtu.be&t=8h6m40s

$ ruby dilute.rb fib.rb
def fi  n
  if n < 3
    1
  else
    fib(n-1  +  ib(n
  end
end

p  ib 34)
$ ruby dilute.rb fib.rb | ruby
5702887

$ D=80C ruby dilute.rb fib.rb
 e    b n



     ib(

 n

   i  3
$ D=80C ruby dilute.rb fib.rb | ruby
5702887

dilute.rb

#!/usr/bin/env ruby

probability = ENV.fetch("D", 10).to_i
ARGF.readlines.each do |line|
  original = line.chomp
  original =~ /([^\r]*)$/
  original = $1
  cr = "#\r"
  diluted = original.chars.map { |c| rand(100) <= probability ? " " : c }.join
  puts original + cr + diluted + " "
end 

fib.rb

def fib n
  if n < 3
    1
  else
    fib(n-1) + fib(n-2)
  end
end

p fib(34)