goal-test.lsp

(defun goal-test (s)
  (cond
    ((null s) t) ; an empty map doesn't have boxes on non-goal squares
    ((has box (first s)) nil)
    (t (goal-test (rest s)))
  )
);end defun

(defun has (item items)
  (cond
    ((null items) nil)
    ((equal item (first items)) t)
    (t (has item (rest items)))
  )
)