diff --git a/lslopt/lslfoldconst.py b/lslopt/lslfoldconst.py
index e003d15..2695abf 100644
--- a/lslopt/lslfoldconst.py
+++ b/lslopt/lslfoldconst.py
@@ -25,6 +25,32 @@ import math
 from lslparse import warning
 from lslfuncopt import OptimizeFunc, OptimizeArgs, FuncOptSetup
 
+
+# Debug
+import sys
+def print_node(node, indent):
+    nt = node['nt']
+    write = sys.stdout.write
+    spaces = ' ' * (indent*4+2)
+    write('%s{ nt:%s\n' % (' '*(indent*4), nt))
+    if 't' in node:
+        write('%s,t:%s\n' % (spaces, node['t']))
+    if 'name' in node:
+        write('%s,name:%s\n' % (spaces, node['name']))
+    if 'value' in node:
+        write('%s,value:%s\n' % (spaces, repr(node['value'])))
+
+    for prop in node:
+        if prop not in ('ch', 'nt', 't', 'name', 'value','X','SEF'):
+            write('%s,%s:%s\n' % (spaces, prop, repr(node[prop])))
+    if 'ch' in node:
+        write(spaces + ',ch:[\n')
+        for subnode in node['ch']:
+            print_node(subnode, indent+1)
+        write(spaces + ']\n')
+    write(' '*(indent*4) + '}\n\n')
+
+
 class foldconst(object):
 
     def isLocalVar(self, node):