title: (Scheme) Find if a item is a member of a leaf in a tree?
body: <p>I'm making a function that checks to see if a item is a member of a leaf in a tree. </p>
  
  <p>This is what I have so far. It's not working right though. Some of the inputs that should be true are returning false. Help please?</p>
  
  <pre><code>(define (leaf-member? item tr)
   (cond
    [(empty-tree? tr) #f]
    [(leaf? tr)
        (if (equal? item tr) #t
            #f)]
    [else (leaf-member? item (cdr tr))]))
  </code></pre>
  
  <p>This is what it should return:</p>
  
  <pre><code>~(leaf-member? 'a (leaf 'a))
  #t
  </code></pre>