title: OCaml -- how to check if two lists match
body: <p>Say I have two lists: </p>
  
  <pre><code>let l1 = [1;2;3];;
  let l2 = [1;2;3];;
  </code></pre>
  
  <p>I am trying to check if they have the same values and order, but if I do</p>
  
  <pre><code>l1 == l2;;
  </code></pre>
  
  <p>I get false. How do I check if they have the same values in the same order?</p>