+/** More reliable version of the form. The former assumes that e is an
+ * expanded epxression. */
+exvector get_all_dummy_indices_safely(const ex & e);
+
+/** Returns b with all dummy indices, which are listed in va, renamed
+ * if modify_va is set to TRUE all dummy indices of b will be appended to va */
+ex rename_dummy_indices_uniquely(exvector & va, const ex & b, bool modify_va = false);
+
+/** Returns b with all dummy indices, which are common with a, renamed */
+ex rename_dummy_indices_uniquely(const ex & a, const ex & b);
+
+/** Same as above, where va and vb contain the indices of a and b and are sorted */
+ex rename_dummy_indices_uniquely(const exvector & va, const exvector & vb, const ex & b);
+
+/** Similar to above, where va and vb are the same and the return value is a list of two lists
+ * for substitution in b */
+lst rename_dummy_indices_uniquely(const exvector & va, const exvector & vb);
+
+/** This function returns the given expression with expanded sums
+ * for all dummy index summations, where the dimensionality of
+ * the dummy index is a nonnegative integer.
+ * Optionally all indices with a variance will be substituted by
+ * indices with the corresponding numeric values without variance.
+ *
+ * @param e the given expression
+ * @param subs_idx indicates if variance of dummy indixes should be neglected
+ */
+ex expand_dummy_sum(const ex & e, bool subs_idx = false);