title: Stack overflow when defining Haskell Fibonacci
body: <p>Just trying to do Exercise 3.7 (p. 31) of Hal Daumé III's YAHT manual, I tried to define the Fibonacci function:</p>
  
  <pre><code>fibo 1 = 1
  fibo 2 = 1
  fibo n = fibo(n-1) + fibo(n-2)
  </code></pre>
  
  <p>I then requested </p>
  
  <pre><code>fibo(3)
  </code></pre>
  
  <p>and got:</p>
  
  <pre><code>*** Exception: stack overflow
  </code></pre>
  
  <p>When I looked into the solution of the exercise I found exactly the same code (with the difference that the function is called fib instead of fibo). What am I doing wrong?</p>
  
  <p>(The manual is from 2006, maybe the language has changed inbetween?)
  (It is ironic that I ask stackoverflow for a problem of stack overflow…)</p>