lispdoc - results for set-difference

(set-difference list1 list2 &key key (test #'eql testp) (test-not nil notp))
Function: Return the elements of LIST1 which are not in LIST2.
Example:
(defun undebug (&rest ids)
  "Stop dbg on the ids.  With no ids, stop dbg altogether."
  (setf *dbg-ids*
          (if (null ids)
              nil
              (set-difference *dbg-ids* ids))))
Mentioned in:
CLtL2 - 15.5. Using Lists as Sets
HyperSpec - Function SET-DIFFERENCE, NSET-DIFFERENCE
PCL - sets
(nset-difference list1 list2 &key key (test #'eql testp) (test-not nil notp))
Function: Destructively return the elements of LIST1 which are not in LIST2.
 Mentioned in:
CLtL2 - 15.5. Using Lists as Sets
HyperSpec - Function SET-DIFFERENCE, NSET-DIFFERENCE