anchor.diff:    (let ((v (make-prbs n init)))
       (labels ((rec (&optional (c 1))
                     (when (> c 0)
  -                    (let ((b (dcar v)))
  -                      (when b
  -                        (setq v (dcdr v))
  -                        (cons (bv->num b) (rec (1- c))))))))
  +                    (cons (bv->num (funcall v)) (rec (1- c))))))
         #'rec)))
   
   (defun byte-gen (n &optional (init #*10))
  
positive.code:                  (bitbv (newbit bv)))))
    
  (defun make-prbs (n &optional (iv #*10))
    "=>  lazy list of repeating `N`-bit bitvectors
  
  `IV` can be provided as an initial bit-vector."
    (let ((taps (taps n)))
      (labels ((rec (v)
                 (dcons v
                        (let ((next (prbs-n v taps)))
                          (rec next)))))
        (rec (num->bv (bv->num iv) n)))))
  
  (defun bvlist-gen (n &optional (init #*10))
    "=> lambda (x)
  
negative.code: `IV` can be provided as an initial bit-vector."
    (let ((v (make-prbs n init)))
      (lambda (&optional (c 1))
        (loop repeat c collecting (funcall v)))))
  
  (defun bit-gen (n &optional (init #*10) (skip 0))
    "return a function representing prbs-N. The returned function takes a single argument which is the number of the next bits to generate from the sequence (default 1 bit)."
    (let ((gen (bvlist-gen n init))
  