anchor.diff:  (defgeneric rete-remove (instans subj pred obj graph)
     (:method ((this instans) subj pred obj graph)
       (if (member :rete-remove (rule-instance-queue-report-p (instans-rule-instance-queue this)))
  -	(format (instans-default-output this) "~%Rete remove from ~A ~A ~A ~A~%"
  +	(format (instans-default-output this) "~&Rete remove from ~A ~A ~A ~A~%~%"
   		 (if graph (sparql-value-to-string graph :instans this) "DEFAULT")
   		 (sparql-value-to-string subj :instans this)
   		 (sparql-value-to-string pred :instans this)
  
positive.code:      (rule-instance-queue-construct-count queue)
       (rule-instance-queue-modify-count queue)))
  
  (defun report-rule-op (op node token &key (variables :project) (stream (instans-default-output (node-instans node))))
    (unless (typep node 'query-node)
      (when (eq variables :project)
        (setf variables :visible)))
    (let* ((instans (node-instans node))
  	 (displayed-bindings (loop for var in (funcall (case variables
  							 (:all #'node-all-vars-out)
  							 (:visible #'node-visible-vars-out)
  							 (:project #'solution-modifiers-project-vars ))
  						       node)
  				   unless (null var)
  				   collect (list (uniquely-named-object-name (reverse-resolve-binding instans var))
  						 (sparql-value-to-string (token-value node token var) :instans instans)))))
      (format stream "~%~A rule ~A in ~A (queue length ~D)~%~{~{       ~A = ~A~}~^~%~}~%"
  	    op (if (rule-node-rule-name node) (format nil "~A (node ~A)" (rule-node-rule-name node) node) node)
  	    (instans-name (node-instans node)) (length (rule-instance-queue-head (instans-rule-instance-queue instans))) displayed-bindings)))
   
  (defgeneric execute-rule-node (node token)
    (:method ((this select-node) token)
  
negative.code:   (null (rule-instance-queue-head queue)))
  
  (defun rule-instance-queue-add (queue node token)
    (let* ((rule-instance (make-instance 'rule-instance :node node :token token))
  	 (new-cell (list rule-instance)))
      (cond ((null (rule-instance-queue-head queue))
  	   (setf (rule-instance-queue-head queue) new-cell)
  	   (setf (rule-instance-queue-tail queue) new-cell))
  