title: Curried anonymous function in SML
body: <p>I have the function below and it works:</p>
  
  <pre><code>(fn x =&gt; x * 2) 2; 
  </code></pre>
  
  <p>but this one doesn't work:</p>
  
  <pre><code>(fn x y =&gt; x + y ) 2 3;
  </code></pre>
  
  <p>Can anyone tell me why? Or give me some hint to get it to work?</p>