title: figuring out an error
body: <p>I asked a few days ago how I would develop a function <code>one</code> which would consume a list of symbols and return the same list but with every instance of <code>cat</code> doubled. </p>
  
  <p>so for example</p>
  
  <pre><code> (one (cons 'animal(cons 'table (cons 'cat (cons 'bread
          empty)))))
  </code></pre>
  
  <p>I would get </p>
  
  <pre><code>(cons 'animal (cons 'table (cons 'cat (cons 'cat (cons 'bread 
      empty)))))
  </code></pre>
  
  <p>heres my part</p>
  
  <pre><code>(define (one alos)
    (cond [(empty? alos)empty]
          [(symbol=? 'cat (first alos)) (cons (first alos) (cons (first alos) (one rest alos)))]
           [else (cons (first alos) (one rest alos))]))
  </code></pre>
  
  <p>I am wondering why I keep getting 'one: expects only 1 argument, but found 2' ? </p>