title: Error of calling function in Scheme
body: <p>my code shows this error - <code>function call: expected a function after the open parenthesis, but received (void)</code></p>
  
  <p>I dont know why. its on the 3rd line</p>
  
  <pre><code>(define countdown
    (lambda (n)
      (cond ((zero? n) (( display "Time") (newline)))
         (else
          ((display n) (newline) (countdown ( - n 1)))))))
  </code></pre>