10                                                               {
   11 
   18 
   20  t4ddg_1(
i, 
j, 
k, 
l) = t2s_2(
i, 
j) * t2s_3(
k, 
l);
 
   22  t4_1(
i, 
j, 
k, 
l) = t2_1(
i, 
j) * t2_2(
k, 
l);
 
   23 
   24  {
   25 
   27 
   28    t4_2(
i, 
j, 
k, 
l) = t4ddg_1(
i, 
j, 
m, 
n) * t4_1(
m, 
n, 
k, 
l);
 
   29 
   31    for (int ii = 0; ii != 3; ++ii) {
   32      for (int jj = 0; jj != 3; ++jj) {
   33        for (int kk = 0; kk != 3; ++kk) {
   34          for (int ll = 0; ll != 3; ++ll) {
   35            for (int mm = 0; mm != 3; ++mm) {
   36              for (int nn = 0; nn != 3; ++nn) {
   37                t4_3(ii, jj, kk, ll) +=
   38                    t4ddg_1(ii, jj, mm, nn) * t4_1(mm, nn, kk, ll);
   39              }
   40            }
   41          }
   42        }
   43      }
   44    }
   45 
   46    for (int ii = 0; ii != 3; ++ii)
   47      for (int jj = 0; jj != 3; ++jj)
   48        for (int kk = 0; kk != 3; ++kk)
   49          for (int ll = 0; ll != 3; ++ll) {
   51                          "t4_2(i, j, k, l) = t4ddg_1(i, j, m, n) * "
   52                          "t4_1(m, n, k, l)");
   53          }
   54  
   55      t4_4(
i, 
j, 
k, 
l) = t4_1(
m, 
n, 
k, 
l) * t4ddg_1(
i, 
j, 
m, 
n);
 
   56 
   57 
   58    for (int ii = 0; ii != 3; ++ii)
   59      for (int jj = 0; jj != 3; ++jj)
   60        for (int kk = 0; kk != 3; ++kk)
   61          for (int ll = 0; ll != 3; ++ll) {
   63                          "t4_2(i, j, k, l) = t4ddg_1(i, j, m, n) * "
   64                          "t4_1(m, n, k, l)");
   65          }
   66 
   67  
   68  }
   69 
   70}
FTensor::Index< 'i', SPACE_DIM > i
const double n
refractive index of diffusive medium
FTensor::Index< 'l', 3 > l
FTensor::Index< 'j', 3 > j
FTensor::Index< 'k', 3 > k
FTensor::Index< 'm', 3 > m
void test_for_zero(const T &t, const std::string &s)