--- esX.py-	2016-09-11 00:00:00.000000000 +0900
+++ esX.py	2016-09-11 01:00:00.000000000 +0900
@@ -114,15 +114,30 @@ def name_bra(lst):
 			return [ f( *lst[:pn] ) ] + name_bra(lst[pn:])
 	return [ lst[0] ] + name_bra(lst[1:])
 
+tstk = []
+
+def dup_lst(v):
+	return [ dup_lst(e) if type(e) == list else e for e in v ]if type(v) == list else v
+
+def tstk_push(v):
+	global tstk
+	tstk.append( dup_lst(v) )
+
+def tstk_pop_ret(v):
+	tstk.pop()
+	return v
+
 def ops_idx(ops, term, op):
 	i = next( ( i for (i, (term_, bind, lst)) in enumerate(ops) if term_ == term and op in lst ), None )
 	if i is None:
+		print yaml.dump(tstk)
 		err_exit("not found term={} op='{}' in ops".format(term, op))
 	return i
 
 def tree_op1(lst, ops, k, v):
 	r = tree_op( lst[1:], ops )
 	if len(r) == 0:
+		print yaml.dump(tstk)
 		err_exit("not found rignt term op='{}'".format(v))
 	(k2, v2) = r[0][:2]
 	if k2 == 'op':
@@ -145,12 +160,14 @@ def op2(ops, e, k1, v1, r0):
 def tree_op2(lst, ops, e, k1, v1):
 	r = tree_op( lst[2:], ops )
 	if len(r) == 0:
+		print yaml.dump(tstk)
 		err_exit("not found right term op='{}'".format(v1))
 	return [ op2( ops, e, k1, v1, r[0] ) ] + r[1:]
 
 def tree_op(lst, ops):
+	tstk_push( [ 'op', lst ] )
 	if len(lst) == 0:
-		return lst
+		return tstk_pop_ret(lst)
 	e = lst[0]
 	(k, v) = e[:2]
 
@@ -162,17 +179,18 @@ def tree_op(lst, ops):
 		e = [ k, v, e[2], e[3], tree_op( [ e[4] ], ops )[0] ]
 
 	if k == 'op':
-		return tree_op1(lst, ops, k, v)
+		return tstk_pop_ret( tree_op1(lst, ops, k, v) )
 
 	if k in [ 'num', 'name', 'arr', 'fcall', 'br_s', 'str' ] and len( lst[1:] ) > 0:
 		e1 = lst[1]
 		(k1, v1) = e1[:2]
 		if k1 == 'op':
 			if v1 in [ '++', '--' ]:  # !!!
-				return [ [ k1, (v1, 'back'), e ] ] + tree_op( lst[2:], ops )
-			return tree_op2(lst, ops, e, k1, v1)
+				ret = [ [ k1, (v1, 'back'), e ] ] + tree_op( lst[2:], ops )
+				return tstk_pop_ret(ret)
+			return tstk_pop_ret( tree_op2(lst, ops, e, k1, v1) )
 
-	return [ e ] + tree_op( lst[1:], ops )
+	return tstk_pop_ret( [ e ] + tree_op( lst[1:], ops ) )
 
 def tree_kwd(lst, kdic):
 	if len(lst) == 0: