anchor.diff:      (when (plusp end-start)
         (error 'invalid-end-index
   	     :end end
  -	     :sequence-length (+ start (- end end-start))))
  +	     :sequence-length (+ start (- end end-start))
  +	     :in-sequence list))
       ;; The variable current now points to a tail
       ;; delimited by end, so we don't touch it.
       ;; Loop through the elements of reversed middle
  
positive.code: 	  finally (when (plusp end-start)
  		    (error 'invalid-end-index
  			   :datum end
  			   :expected-type `(integer 0 ,(- end end-start)))))))
  
  (defun |count seq-type=list from-end=nil end=other key=identity test-not=other|
      (item list start end test-not)
  
negative.code: 	  finally (when (plusp end-start)
  		    (error 'invalid-end-index
  			   :datum end
  			   :expected-type `(integer 0 ,(- end end-start))
  			   :in-sequence list)))))
  
  (defun |count seq-type=list from-end=t end=other key=identity test=other|
      (item list start end test)
  