(let ((g (* 2 (or (gethash word good) 0)))       
      (b (or (gethash word bad) 0)))    
   (unless (< (+ g b) 5)      
     (max .01           
          (min .99 (float (/ (min 1 (/ b nbad))                                    
                             (+ (min 1 (/ g ngood))                                   
                             (min 1 (/ b nbad)))))))))

##</code><code>##

(let ((prod (apply #'* probs)))   
  (/ prod (+ prod (apply #'* (mapcar #'(lambda (x) (- 1 x))                                      
                                     probs)))))