anchor.diff:                             (lambda (chunk)
                                (incf index) 
                                (setf header-level
  -                                   (header-p chunk :depth depth)))))))
  +                                   (header-p chunk :depth depth :start start)))))))
       (iterate-elements 
        header-indexes
        (lambda (datum)
  
positive.code: (defun set-property (phase args result)
    ;; {set-property name value}
    (declare (ignore result))
    (assert (eq phase :parse))
    (if (length-at-least-p args 2)
      (bind (((name &rest value) args))
        (setf value (format nil "~{~a~^ ~}" value))
        (setf (document-property name) value))
      (warn "Not enough arguments to set-property (need at least 2)"))
    nil)
  
  
  
negative.code: 
  ;;; ---------------------------------------------------------------------------
  
  (defun add-anchors (document &key depth start)
    (let* ((index -1)
           (header-level nil)
           (header-indexes (nreverse
  