anchor.diff:    (nlet recur ((node (get-node dawg 0)))
       (if (stream:eos? in)
           (terminal? node)
  -      (when (check-encoded-children in node)
  -        (let* ((arc (stream:read in))
  +      (when (check-encoded-children in node dawg)
  +        (let* ((arc (arc (stream:read in) dawg))
                  (next (get-node dawg (+ (base node) arc))))
             (when (= (chck next) arc)
               (recur next)))))))
  
positive.code:       (unless (or (eq byte-order :native)
                    (eq byte-order +NATIVE_ORDER+))
          (let ((byte-size (ecase element-type
                             (uint4 4)
                             (uint8 8))))
            (dotimes (i size)
  
negative.code: ;;; declamation
  (declaim (inline check-encoded-children get-node 
                   base chck terminal? sibling-total inc-id 
                   get-id-impl member?-impl)
           (ftype (function #.*args-type* boolean) member?)
           (ftype (function #.*args-type* (or null positive-fixnum)) get-id))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;; auxiliary function(1)
  (defun read-count (filepath byte-order)
    (with-open-file (in filepath :element-type 'uint4)
      (if (or (eq byte-order :native)
              (eq byte-order +NATIVE_ORDER+))
          (read-byte in)
        (byte-reverse (read-byte in) 4))))
  
  (defun read-array (index-path &key size element-type offset byte-order)
    (declare ((member uint1 uint4 uint8) element-type))
    (with-open-file (in index-path :element-type element-type)
      (file-position in offset)
      (let ((ary (make-array size :element-type element-type)))
  