anchor.diff:                          0)))) )
   
   (defun build-search-node ()
  -  (cons (cons 1 1) 0))
  +  (cons 0 (cons (cons 1 1) 0)))
   
   (defun build-demo-world ()
     (cons (build-map)
  
positive.code: (defun ids-path-to-pill (x y map-tree width treedepth)
      (ids 1             ;; could also start with bigger search for speed
                         ;; (at the expense of accuracy, of course)
           (cons (cons (cons x y) 0) 0) ;; search node in list
           0
           map-tree width treedepth))
  
  
negative.code: 
  (defun search-node-is-dot (searchnode map-tree width treedepth)
    (member
      (map-tree-lookup (car (car (cdr searchnode)))
                       (cdr (car (cdr searchnode)))
                       map-tree
                       width
                       treedepth)
  