title: How can I declare an empty tuple?
body: <p>I can declare empty list as <code>[]</code>, but, how can I declare empty tuple?</p>
  
  <p>I have tried:</p>
  
  <pre><code>for ( , ) 
  ghci&gt;(1,0 ) : [(,)] 
  </code></pre>
  
  <p>but it gives me an error!</p>