title: Racket - Applying a Boolean to a list of lists
body: <p>I have a function that utilizes a Boolean to replace the first number in a list with 1, regardless of its value:</p>
  
  <p>f({(0, 1, 0), (0, 0, 1), (1, 0, 0), ...}) = {(1, 1, 0), (1, 0, 1), (1, 0, 0), ...}</p>
  
  <p>So far I have</p>
  
  <pre><code>(define (procB set)
    (map (λ (lst1) ((number? (first lst1)) (cons 1 (rest lst1)))) set))
  </code></pre>
  
  <p>The trouble is when the function is applied to the remaining parts of the set.  I get the standard error</p>
  
  <pre><code>application: not a procedure;
  expected a procedure that can be applied to arguments
   given: #t
  </code></pre>
  
  <p>I get that it isn't working because there is a Boolean (given: #t), but I am not quite sure how to fix it.</p>