diff --git a/scsh/xanadu/b-tree.scm b/scsh/xanadu/b-tree.scm
index 05c5fd2..8a01954 100644
--- a/scsh/xanadu/b-tree.scm
+++ b/scsh/xanadu/b-tree.scm
@@ -93,14 +93,14 @@
         ))))
 
     (define (search-rec str tree side-string) ;; root param in b-treenode
-      (let* ((side-tree ((tree side-string)))
+      (let* ((side-tree (tree side-string))
              (len (vector-length side-tree)))
         (do ((i 0 (+ i 1)))
-            ((let* ((side-tree-el-first ((vector-ref side-tree i))))
-               (cond ((>= i len 1);;last node
+            ((let* ((side-tree-el-first (vector-ref side-tree i)))
+               (cond ((>= i len);;last node
                       (do ((j 0 (+ j 1)))
                           ((= j len) 0)
-                        (search-rec str (vector-ref j side-tree))))
+                        (search-rec str (vector-ref side-tree j))))
                      ((let ((side-tree-el-second ((vector-ref side-tree (+ i 1)))))
                         (and (string<? str
                                        ((side-tree-el-first 'get-data)))