diff --git a/src/arithmetic_container.py b/src/arithmetic_container.py
index 19b08723dfdd208b7c6244de359834652dca36d7..23845cad83bd64445ae8da4262b61cbdc230c9d6 100644
--- a/src/arithmetic_container.py
+++ b/src/arithmetic_container.py
@@ -131,6 +131,16 @@ class ArithmeticList(list):
     def __repr__(self):
         return "ArithmeticList(%s)" % list.__repr__(self)
 
+    def plus(self, other):
+        """Return a copy of self extended by the entries from the iterable
+        C{other}.
+        
+        Makes up for the loss of the C{+} operator (which is now arithmetic).
+        """
+        result = ArithmeticList(self)
+        result.extend(other)
+        return result
+