title: Polymorphic recursion - syntax and uses?
body: <p>I've spent significant time looking over learnyouahaskell and I haven't found a good explanation of polymorphic recursion!</p>
  
  <p>I understand basic recursive structures:</p>
  
  <pre><code>myFunction :: [Int] -&gt; [Int]
  myFunction [] = []
  myFunction (x : xs) = (\x -&gt; x + 1) x : myFunction xs
  </code></pre>
  
  <p>What would polymorphic recursion look like? And what are its benefits/uses?</p>