title: Sum function work with recursion and multiple arguments
body: <p>Is there a away to create a sum function that works with both recursive call (e.g (1)(2)(3)(4)), and multiple arguments (e.g (1, 2, 3, 4))?</p>
  
  <p>Like this:</p>
  
  <pre><code>sum(5, 5) // 10
  sum(5)(5) // 10
  </code></pre>
  
  <p>Thank you.</p>