anchor.diff:  
   ;;;; Brett Commandeur
   ;;;; 1255891
  -;;;; CMPUT 325 Wi17 - NON-PROCEDURAL PROG LANGUAGES Combined LAB LEC Wi17
  +;;;; CMPUt 325 Wi17 - NON-PROCEDURAL PROG LANGUAGES Combined LAB LEC Wi17
   
   #|--- TODO: Remove this comment
   
  -Acceptable built-in functions: 
  +Acceptable built-in functions:
   
   (atom x)
   (null x)
  
positive.code: - (cadr ...)
  (cdr x)
  - (cdaar ...)
  (cons x y) 
  (if x y z)
  (cond ... ) 
  (let ((x y) (u v)) z)
  (let* ((x y) (u v)) z)
  (defun ...)
  
negative.code: (list x1 x2 ...)
  (print ...)
  (sort L fun) % this is useful for the last problem
  (copy-list L) % useful in conjunction with sort
  - http://clhs.lisp.se/Body/f_cp_lis.htm#copy-list
  - (sort (copy-list L) sort-predicate)
  
  