title: Value or constructor is not defined
body: <p>I'm learning f# and I've got a pretty trivial problem that doesn't seem to make sense. I'm working on Project Euler problem 2 and I've got this:</p>
  
  <pre><code>let fib (x : BigInteger) (y : BigInteger) (max : BigInteger) = 
      let added = x + y
      if added &gt; max then y
      else fib y (x + y) max
  </code></pre>
  
  <p>I've got the error at the recursive fib call:</p>
  
  <blockquote>
    <p>Value or constructor 'fib' is not defined</p>
  </blockquote>
  
  <p>And I'm not sure why. Any help?</p>