title: Undefined function in DrScheme?
body: <p>Hey i'm just trying to write some code in DrScheme:
  ((function (x) (* x x)) 2)</p>
  
  <p>but i got a message saying:
  reference to undefined identifier: function</p>
  
  <p>I'm using language "Essentials of Programming languages (3rd ed.)" and the version of DrScheme is 4.2.1</p>
  
  <p>Thanks!</p>