documentation update

diff --git a/ginac/indexed.h b/ginac/indexed.h
index f4891490a09d7d8b84521e17773977025074c11b..aac4625c8d6f37a4ca06b461222ec3ff3c2ca993 100644 (file)
--- a/ginac/indexed.h
+++ b/ginac/indexed.h
@@ -172,7 +172,8 @@ public:
        exvector get_dummy_indices() const;
 
        /** Return a vector containing the dummy indices in the contraction with
-        *  another indexed object. */
+        *  another indexed object. This is symmetric: a.get_dummy_indices(b)
+        *  == b.get_dummy_indices(a) */
        exvector get_dummy_indices(const indexed & other) const;
 
        /** Check whether the object has an index that forms a dummy index pair