anchor.diff:    (with-rule-components ((doc-string lhs rhs) body)
       (format t "LHS: ~S~%" lhs)
       (format t "RHS: ~S~%" rhs)
  -    (break)
       (add-new-rule 
        (inference-engine)
        (make-rule name (inference-engine) lhs rhs
  
positive.code: ;;; modify) is performed elsewhere as these constructs undergo additional
  ;;; transformations.
  ;;;
  ;;; $Id: parser.lisp,v 1.29 2002/09/26 15:44:58 youngde Exp $
  
  (in-package "LISA")
  
  
negative.code: (defmacro make-equality-predicate (var atom)
    `(function
      (lambda ()
        (equal (symbol-value ,var) ,atom))))
  
  (defun make-generic-predicate (forms)
    (eval `(function (lambda () (progn ,@forms)))))
  
  (defun find-or-set-slot-binding (var slot-name location)
    (multiple-value-bind (binding existsp)
  