anchor.diff:  	(if test
   	    (cond ((or (eq test #'eq) (eq test 'eq))
   		   (if use-hash
  -		       (set-difference-key-eq-hash list1 list2 key)
  -		       (set-difference-key-eq list1 list2 key)))
  +		       (set-difference-key-eq-hash 'nset-difference list1 list2 key)
  +		       (set-difference-key-eq 'nset-difference list1 list2 key)))
   		  ((or (eq test #'eql) (eq test 'eql))
   		   (if use-hash
  -		       (set-difference-key-eql-hash list1 list2 key)
  -		       (set-difference-key-eql list1 list2 key)))
  +		       (set-difference-key-eql-hash 'nset-difference list1 list2 key)
  +		       (set-difference-key-eql 'nset-difference list1 list2 key)))
   		  ((or (eq test #'equal) (eq test 'equal))
   		   (if use-hash
  -		       (set-difference-key-equal-hash list1 list2 key)
  -		       (set-difference-key-test list1 list2 key #'equal)))
  +		       (set-difference-key-equal-hash 'nset-difference list1 list2 key)
  +		       (set-difference-key-test 'nset-difference list1 list2 key #'equal)))
   		  ((or (eq test #'equalp) (eq test 'equalp))
   		   (if use-hash
  -		       (set-difference-key-equalp-hash list1 list2 key)
  -		       (set-difference-key-test list1 list2 key #'equalp)))
  +		       (set-difference-key-equalp-hash 'nset-difference list1 list2 key)
  +		       (set-difference-key-test 'nset-difference list1 list2 key #'equalp)))
   		  (t
  -		   (set-difference-key-test list1 list2 key test)))
  +		   (set-difference-key-test 'nset-difference list1 list2 key test)))
   	    (if test-not
  -		(set-difference-key-test-not list1 list2 key test-not)
  +		(set-difference-key-test-not 'nset-difference list1 list2 key test-not)
   		(if use-hash
  -		    (set-difference-key-eql-hash list1 list2 key)
  -		    (set-difference-key-eql list1 list2 key))))
  +		    (set-difference-key-eql-hash 'nset-difference list1 list2 key)
  +		    (set-difference-key-eql 'nset-difference list1 list2 key))))
   	(if test
   	    (cond ((or (eq test #'eq) (eq test 'eq))
   		   (if use-hash
  -		       (set-difference-identity-eq-hash list1 list2)
  -		       (set-difference-identity-eq list1 list2)))
  +		       (set-difference-identity-eq-hash 'nset-difference list1 list2)
  +		       (set-difference-identity-eq 'nset-difference list1 list2)))
   		  ((or (eq test #'eql) (eq test 'eql))
   		   (if use-hash
  -		       (set-difference-identity-eql-hash list1 list2)
  -		       (set-difference-identity-eql list1 list2)))
  +		       (set-difference-identity-eql-hash 'nset-difference list1 list2)
  +		       (set-difference-identity-eql 'nset-difference list1 list2)))
   		  ((or (eq test #'equal) (eq test 'equal))
   		   (if use-hash
  -		       (set-difference-identity-equal-hash list1 list2)
  -		       (set-difference-identity-test list1 list2 #'equal)))
  +		       (set-difference-identity-equal-hash 'nset-difference list1 list2)
  +		       (set-difference-identity-test 'nset-difference list1 list2 #'equal)))
   		  ((or (eq test #'equalp) (eq test 'equalp))
   		   (if use-hash
  -		       (set-difference-identity-equalp-hash list1 list2)
  -		       (set-difference-identity-test list1 list2 #'equalp)))
  +		       (set-difference-identity-equalp-hash 'nset-difference list1 list2)
  +		       (set-difference-identity-test 'nset-difference list1 list2 #'equalp)))
   		  (t
  -		   (set-difference-identity-test list1 list2 test)))
  +		   (set-difference-identity-test 'nset-difference list1 list2 test)))
   	    (if test-not
  -		(set-difference-identity-test-not list1 list2 test-not)
  +		(set-difference-identity-test-not 'nset-difference list1 list2 test-not)
   		(if use-hash
  -		    (set-difference-identity-eql-hash list1 list2)
  -		    (set-difference-identity-eql list1 list2)))))))
  +		    (set-difference-identity-eql-hash 'nset-difference list1 list2)
  +		    (set-difference-identity-eql 'nset-difference list1 list2)))))))
   
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
   ;;;
  
positive.code: ;;;
  ;;; Function set-difference
  
  (defun set-difference-identity-eql (list1 list2)
    (loop for element in list1
  	unless (member element list2)
  	  collect element))
  
  (defun set-difference-identity-eq (list1 list2)
    (loop for element in list1
  	unless (member element list2 :test #'eq)
  	  collect element))
  
  (defun set-difference-key-eql (list1 list2 key)
    (loop for element in list1
  	unless (member (funcall key element) list2 :key key)
  	  collect element))
  
  (defun set-difference-key-eq (list1 list2 key)
    (loop for element in list1
  	unless (member (funcall key element) list2 :test #'eq :key key)
  	  collect element))
  
  (defun set-difference-identity-test (list1 list2 test)
    (loop for element in list1
  	unless (member element list2 :test test)
  	  collect element))
  
  (defun set-difference-key-test (list1 list2 key test)
    (loop for element in list1
  	unless (member (funcall key element) list2 :test test :key key)
  	  collect element))
  
  (defun set-difference-identity-test-not (list1 list2 test-not)
    (loop for element in list1
  	unless (member element list2 :test-not test-not)
  	  collect element))
  
  (defun set-difference-key-test-not (list1 list2 key test-not)
    (loop for element in list1
  	unless (member (funcall key element) list2 :test-not test-not :key key)
  	  collect element))
  
  (defun set-difference-identity-eq-hash (list1 list2)
    (let ((table (make-hash-table :test #'eq)))
      (loop for element in list2
  	  do (setf (gethash element table) t))
      (loop for element in list1
  	  unless (gethash element table)
  	    collect element)))
  
  (defun set-difference-identity-eql-hash (list1 list2)
    (let ((table (make-hash-table :test #'eql)))
      (loop for element in list2
  	  do (setf (gethash element table) t))
      (loop for element in list1
  	  unless (gethash element table)
  	    collect element)))
  
  (defun set-difference-identity-equal-hash (list1 list2)
    (let ((table (make-hash-table :test #'equal)))
      (loop for element in list2
  	  do (setf (gethash element table) t))
      (loop for element in list1
  	  unless (gethash element table)
  	    collect element)))
  
  (defun set-difference-identity-equalp-hash (list1 list2)
    (let ((table (make-hash-table :test #'equalp)))
      (loop for element in list2
  	  do (setf (gethash element table) t))
      (loop for element in list1
  	  unless (gethash element table)
  	    collect element)))
  
  (defun set-difference-key-eq-hash (list1 list2 key)
    (let ((table (make-hash-table :test #'eq)))
      (loop for element in list2
  	  do (setf (gethash (funcall key element) table) t))
      (loop for element in list1
  	  unless (gethash (funcall key element) table)
  	    collect element)))
  
  (defun set-difference-key-eql-hash (list1 list2 key)
    (let ((table (make-hash-table :test #'eql)))
      (loop for element in list2
  	  do (setf (gethash (funcall key element) table) t))
      (loop for element in list1
  	  unless (gethash (funcall key element) table)
  	    collect element)))
  
  (defun set-difference-key-equal-hash (list1 list2 key)
    (let ((table (make-hash-table :test #'equal)))
      (loop for element in list2
  	  do (setf (gethash (funcall key element) table) t))
      (loop for element in list1
  	  unless (gethash (funcall key element) table)
  	    collect element)))
  
  (defun set-difference-key-equalp-hash (list1 list2 key)
    (let ((table (make-hash-table :test #'equalp)))
      (loop for element in list2
  	  do (setf (gethash (funcall key element) table) t))
      (loop for element in list1
  	  unless (gethash (funcall key element) table)
  	    collect element)))
  
  (defun set-difference (list1 list2 &key key test test-not)
    (when (and (not (null test)) (not (null test-not)))
  
negative.code: 	(if test
  	    (cond ((or (eq test #'eq) (eq test 'eq))
  		   (if use-hash
  		       (set-difference-key-eq-hash 'set-difference list1 list2 key)
  		       (set-difference-key-eq 'set-difference list1 list2 key)))
  		  ((or (eq test #'eql) (eq test 'eql))
  		   (if use-hash
  		       (set-difference-key-eql-hash 'set-difference list1 list2 key)
  		       (set-difference-key-eql 'set-difference list1 list2 key)))
  		  ((or (eq test #'equal) (eq test 'equal))
  		   (if use-hash
  		       (set-difference-key-equal-hash 'set-difference list1 list2 key)
  		       (set-difference-key-test 'set-difference list1 list2 key #'equal)))
  		  ((or (eq test #'equalp) (eq test 'equalp))
  		   (if use-hash
  		       (set-difference-key-equalp-hash 'set-difference list1 list2 key)
  		       (set-difference-key-test 'set-difference list1 list2 key #'equalp)))
  		  (t
  		   (set-difference-key-test 'set-difference list1 list2 key test)))
  	    (if test-not
  		(set-difference-key-test-not 'set-difference list1 list2 key test-not)
  		(if use-hash
  		    (set-difference-key-eql-hash 'set-difference list1 list2 key)
  		    (set-difference-key-eql 'set-difference list1 list2 key))))
  	(if test
  	    (cond ((or (eq test #'eq) (eq test 'eq))
  		   (if use-hash
  		       (set-difference-identity-eq-hash 'set-difference list1 list2)
  		       (set-difference-identity-eq 'set-difference list1 list2)))
  		  ((or (eq test #'eql) (eq test 'eql))
  		   (if use-hash
  		       (set-difference-identity-eql-hash 'set-difference list1 list2)
  		       (set-difference-identity-eql 'set-difference list1 list2)))
  		  ((or (eq test #'equal) (eq test 'equal))
  		   (if use-hash
  		       (set-difference-identity-equal-hash 'set-difference list1 list2)
  		       (set-difference-identity-test 'set-difference list1 list2 #'equal)))
  		  ((or (eq test #'equalp) (eq test 'equalp))
  		   (if use-hash
  		       (set-difference-identity-equalp-hash 'set-difference list1 list2)
  		       (set-difference-identity-test 'set-difference list1 list2 #'equalp)))
  		  (t
  		   (set-difference-identity-test 'set-difference list1 list2 test)))
  	    (if test-not
  		(set-difference-identity-test-not 'set-difference list1 list2 test-not)
  		(if use-hash
  		    (set-difference-identity-eql-hash 'set-difference list1 list2)
  		    (set-difference-identity-eql 'set-difference list1 list2)))))))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  