diff --git a/formal.py b/formal.py
index 861a8bb..a9f34f0 100644
--- a/formal.py
+++ b/formal.py
@@ -35,7 +35,7 @@ class FormalExp(object):
         :returns: a_n
 
         """
-        pattern = "\w\*\*(\d*)"
+        pattern = "\w\^(\d*)"
         finder = re.compile(pattern)
         power = {}
         for (k,v) in self._coef.items():
@@ -135,12 +135,12 @@ class FormalExp(object):
 
     def __str__(self):
         return " + ".join([str(v) + str(k) for k,v in self._coef.items()])
-    
+
 if __name__ == '__main__':
     fe1 = FormalExp({"x": 1, "":2})    
-    print(fe1)
-    fe2 = FormalExp({"x**12": 5, "":2})    
-    print(fe2)
+    print(fe1.get_postfix())
+    fe2 = FormalExp({"x^12": 5, "":2})    
+    print(fe2.get_postfix())
     fe3 = fe1 * fe2
     for s in fe3:
         print(s)
diff --git a/render.py b/render.py
index 05bf1ce..995f430 100644
--- a/render.py
+++ b/render.py
@@ -243,13 +243,12 @@ tex_render = Render(tex_infix, tex_postfix, tex_other, type_render = tex_type_re
 
 if __name__ == '__main__':
     exp = [2, 5, '+', 1, '-', 3, 4, '*', '/']
-    print(txt(exp))
+    print(txt_render(exp))
     exp = [2, 5, '+', 1, '-', 3, 4, '*', '/', 3, '+']
-    print(tex(exp))
+    print(tex_render(exp))
     exp = [2, 5, '+', 1, '-', 3, 4, '*', '/', 3, '+']
     print(post2in_fix(exp))
     
-
 # -----------------------------
 # Reglages pour 'vim'
 # vim:set autoindent expandtab tabstop=4 shiftwidth=4: