--- esw.py-	2016-09-29 00:00:00.000000000 +0900
+++ esw.py	2016-09-30 00:00:00.000000000 +0900
@@ -140,17 +140,21 @@ def ops_idx(ops, term, op):
 		err_not_found("term={} op='{}' in ops".format(term, op))
 	return i
 
+def op1(ops, k, v, r0):
+	(k2, v2) = r0[:2]
+	if k2 == 'op':
+		i1 = ops_idx(ops, 1, v)
+		i2 = ops_idx( ops, len( r0[2:] ), v2 )
+		if i1 < i2 or (i1 == i2 and ops[i1][1] == '>'):
+			r02 = op1( ops, k, v, r0[2] )
+			return [ k2, v2, r02 ] + r0[3:]
+	return [ k, v, r0 ]
+
 def tree_op1(lst, ops, k, v):
 	r = tree_op( lst[1:], ops )
 	if len(r) == 0:
 		err_not_found("rignt term op='{}'".format(v))
-	(k2, v2) = r[0][:2]
-	if k2 == 'op':
-		i1 = ops_idx(ops, 1, v)
-		i2 = ops_idx( ops, len( r[0][2:] ), v2 )
-		if i1 < i2 or (i1 == i2 and ops[i1][1] == '>'):
-			return [ [ k2, v2, [ k, v, r[0][2] ] ] + r[0][3:] ] + r[1:]
-	return [ [ k, v, r[0] ] ] + r[1:]
+	return [ op1( ops, k, v, r[0] ) ] + r[1:]
 
 def op2(ops, e, k1, v1, r0):
 	(k2, v2) = r0[:2]