title: Fibonacci sequence in SML
body: <pre><code>  1 fun fib 0 = 0                                                                   
    2     | fib 1 = 1                                                                 
    3     | fib n = (fib n-1) + (fib n-2)                                             
    4                                                                                 
    5 val x = fib 8 
  </code></pre>
  
  <p>What's incorrect about this implementation of the nth number in the fibonacci sequence? When I run the program it just hangs...</p>