9{
   12 
   16 
   17  
   19  t2(
i, 
j) = t2_1(
i, 
j);
 
   20 
   21  
   22 
   23  
   24 
   25  t2(
j, 
i) += t2_2(
i, 
j);
 
   26  test_for_zero(t2(0, 0) - (t2_1(0, 0) + t2_2(0, 0)), 
"T2(j,i)+=T2(i,j)(0,0)");
 
   27  test_for_zero(t2(1, 0) - (t2_1(1, 0) + t2_2(0, 1)), 
"T2(j,i)+=T2(i,j)(0,1)");
 
   28  test_for_zero(t2(2, 0) - (t2_1(2, 0) + t2_2(0, 2)), 
"T2(j,i)+=T2(i,j)(0,2)");
 
   29  test_for_zero(t2(0, 1) - (t2_1(0, 1) + t2_2(1, 0)), 
"T2(j,i)+=T2(i,j)(1,0)");
 
   30  test_for_zero(t2(1, 1) - (t2_1(1, 1) + t2_2(1, 1)), 
"T2(j,i)+=T2(i,j)(1,1)");
 
   31  test_for_zero(t2(2, 1) - (t2_1(2, 1) + t2_2(1, 2)), 
"T2(j,i)+=T2(i,j)(1,2)");
 
   32  test_for_zero(t2(0, 2) - (t2_1(0, 2) + t2_2(2, 0)), 
"T2(j,i)+=T2(i,j)(2,0)");
 
   33  test_for_zero(t2(1, 2) - (t2_1(1, 2) + t2_2(2, 1)), 
"T2(j,i)+=T2(i,j)(2,1)");
 
   34  test_for_zero(t2(2, 2) - (t2_1(2, 2) + t2_2(2, 2)), 
"T2(j,i)+=T2(i,j)(2,2)");
 
   35}
FTensor::Index< 'i', SPACE_DIM > i
FTensor::Index< 'j', 3 > j
void test_for_zero(const T &t, const std::string &s)