*
* If for example the first index (<code>index_1==0</code>) of a tensor
* <code>t1</code> shall be contracted with the third index
- * (<code>index_2==2</code>) of a tensor <code>t2</code>, the invocation of
- * this function is
+ * (<code>index_2==2</code>) of a tensor <code>t2</code>, this function should
+ * be invoked as
* @code
* contract<0, 2>(t1, t2);
* @endcode
* If for example the first index (<code>index_1==0</code>) shall be
* contracted with the third index (<code>index_2==2</code>), and the second
* index (<code>index_3==1</code>) with the first index
- * (<code>index_4==0</code>) the invocation of this function is this function
- * is
+ * (<code>index_4==0</code>) of a tensor <code>t2</code>, this function should
+ * be invoked as
* @code
* double_contract<0, 2, 1, 0>(t1, t2);
* @endcode