No joke! See this thread: https://news.ycombinator.com/item?id=11561336 https://news.ycombinator.com/item?id=11561336 for some real-life implementations of thi

No joke! See this thread: https://news.ycombinator.com/item?id=11561336 https://news.ycombinator.com/item?id=11561336 for some real-life implementations of this technique. Since the Fibonacci numbers are integers, at the end of your computation you'll get a number like "a + 0 sqrt(5)". Then you can just take the "a" part.