anchor.diff:                  (rec (rope-list-cat rope)))
                  (array
                   (rec (rope-array-cat rope)))
  -               (t (rec (object-rope rope))))))
  +               (t (rec (object-rope-check rope))))))
       (rec rope)))
   
   (declaim (ftype (function (t t) rope) %rope))
  +
   (defun %rope (first second)
     "Construct a rope from FIRST and SECOND.
   FIRST: an object of rope or sequence type
  
positive.code:             (rope-array-cat tmp))))))
  
  (defun rope-parenthesize (a)
    (rope "(" a ")"))
  
negative.code:                          '|)|))))
         rope))
  
  
  (defmethod object-rope ((object string))
    object)
  