From: "obstinate.jack@..." <obstinate.jack@...>
Date: 2007-03-04T15:55:04+09:00
Subject: Re: Programming Ruby book p.50 (Fibonacci yield example)

I happen to have this book as well. There's actually a comment
immediate to the right of the line i1, i2 = 1, 1 and says # parallel
assignment (i1 = 1 and i2 =1)

i1, i2 = i2, i1+i2
is another way of writing
temp = i1
i1 = i2
i2 = temp+i2