mjo/clan/clan_element.py: fix parent of inner_product()

The inner product of two clan elements should live in the base ring of
the clan.

diff --git a/mjo/clan/clan_element.py b/mjo/clan/clan_element.py
index 7c0314252d61df460336ec1c9d98f99263038057..b125d1c2e0237e97cb5b122973760f02cf6ec83e 100644 (file)
--- a/mjo/clan/clan_element.py
+++ b/mjo/clan/clan_element.py
@@ -24,6 +24,7 @@ class ClanElement(IndexedFreeModuleElement):
 
         SETUP::
 
+            sage: from mjo.clan.random import random_clan
             sage: from mjo.clan.t_algebra_clan import RealSymmetricClan
 
         EXAMPLES:
@@ -39,8 +40,18 @@ class ClanElement(IndexedFreeModuleElement):
             ....:      if j == i )
             True
 
+        TESTS:
+
+        The result should live in the clan's base ring::
+
+            sage: C = random_clan()
+            sage: x = C.random_element()
+            sage: y = C.random_element()
+            sage: x.inner_product(y) in C.base_ring()
+            True
+
         """
-        return sum(
+        return self.base_ring().sum(
             xi*yj*self.parent().inner_product_on_basis(bi, bj)
             for (bi, xi) in self.items()
             for (bj, yj) in other.items()