diff --git a/src/operation.py b/src/operation.py
index d3e752fbd70176310d3b959e9a97b47caa510183..ac96c1b117d8feb77bc8318aac4a07c2cb76e347 100644
--- a/src/operation.py
+++ b/src/operation.py
@@ -6,7 +6,7 @@ def degree(x):
 
     
 def gcd_extended(x, y):
-    
+    pass
 
 
 
diff --git a/src/traits.py b/src/traits.py
index aa6222ab9822d71ef55384f2307b5fb2a56972f0..9fe8d0ddae0c0315cd2a63e110c5b75844a31d93 100644
--- a/src/traits.py
+++ b/src/traits.py
@@ -31,11 +31,11 @@ class Traits:
 
         "Degree" is used as in the definition of a Euclidean ring,
         see [Bosch], p. 42
-        """"
+        """
         raise NotImplementedError
 
     def gcd_extended(self, q, r): 
-        """Returns a tuple 
+        """Returns a tuple ..."""
 
     def gcd(self): raise NotImplementedError
     def lcm(self): raise NotImplementedError