anchor.diff:      `(defquery (gensym)
          ,@body
          =>
  +       (format t "Firing query~%")
          (push (list ,@(mapcar #'make-query-binding varlist)) *query-result*))))
  
positive.code: 
  (defun define-and-run-query (name body)
    (let ((*query-result* '())
          (query-engine (make-rete)))
      (setf (get-facts query-engine) (get-facts (current-engine)))
      (add-rule query-engine (define-rule name body))
      (run-engine query-engine)
      (values *query-result*)))
  
  (defmacro defquery (name &body body)
    (let ((rule-name (gensym)))
  
negative.code: ;;; Description: Macros and functions implementing LISA's early attempt at a
  ;;; query language.
  
  ;;; $Id: retrieve.lisp,v 1.5 2002/01/10 16:36:59 youngde Exp $
  
  (in-package "LISA")
  
  