anchor.diff:           (production-file (make-pathname :name exercise
                                            :type "lisp"
                                            :defaults exercise-directory)))
  -    (write-production-code production-file test-data)))
  +    (write-production-code production-file test-data)
  +    (format *standard-output* "Wrote ~A~&" production-file)))
   
   (defun make-example-code (test-data)
     (let* ((exercise (exercise-name test-data))
  
positive.code:          (example-file (make-pathname :name "example"
                                           :type "lisp"
                                           :defaults exercise-directory)))
      (write-production-code example-file test-data)))
  
  (defun generate (exercise)
    (let ((test-data (read-exercise-data (canonical-data-pathname exercise))))
  
negative.code:                             :if-exists :supersede)
        (write-prologue stream test-data)
        (write-tests stream test-data)
        (write-epilogue stream test-data))
      (format *standard-output* "Wrote ~A~&" test-file)))
  
  (defun write-production-code (file test-data)
    (with-open-file (stream file
  