anchor.diff:      (set-property startnode prop-name 0)
       (let ( (cur-nodes (list startnode))
             cur-node distance suc-nodes suc-dist )
  -      (while cur-nodes
  +      (loop :while cur-nodes :do
           (setf cur-node (car cur-nodes)
                 cur-nodes (cdr cur-nodes)
                 distance (1+ (get-property cur-node prop-name))
  
positive.code:       (set-property startnode stamp t)
        (let ((cur-nodes (list startnode))
              cur-node)
          (while cur-nodes
            (setq cur-node  (car cur-nodes)
                  cur-nodes (cdr cur-nodes))
            (dolist (edge (directed-edges-from-node self cur-node))
  
negative.code:         "COM.INFORMATIMAGO.COMMON-LISP.CESARUM.SET")
    (:shadowing-import-from "COMMON-LISP"
                            "UNION" "INTERSECTION" "MERGE")
    (:export "EDGE-CLASS" "EDGES" "NODES" "TO" "FROM" "WEIGHT" "INDEX"
             "ELEMENTS" "PROPERTIES" "IDENT" "SHOW-GRAPH" "FIND-NODES-WITH-PROPERTY"
             "COPY" "WALK-EDGES-FROM-NODE" "WALK-FROM-NODE" "FLOW-DISTANCE-FROM-NODE"
  