20  t3dg_1(
i, 
j, 
k) = t3dg_2(
i, 
j, 
k) - t3dg_3(
i, 
j, 
k);
 
   21  test_for_zero(t3dg_1(0, 0, 0) - (t3dg_2(0, 0, 0) - t3dg_3(0, 0, 0)),
 
   22                "T3dg(i,j,k)-T3dg(i,j,k)(0,0,0)");
 
   23  test_for_zero(t3dg_1(0, 0, 1) - (t3dg_2(0, 0, 1) - t3dg_3(0, 0, 1)),
 
   24                "T3dg(i,j,k)-T3dg(i,j,k)(0,0,1)");
 
   25  test_for_zero(t3dg_1(0, 0, 2) - (t3dg_2(0, 0, 2) - t3dg_3(0, 0, 2)),
 
   26                "T3dg(i,j,k)-T3dg(i,j,k)(0,0,2)");
 
   27  test_for_zero(t3dg_1(0, 1, 0) - (t3dg_2(0, 1, 0) - t3dg_3(0, 1, 0)),
 
   28                "T3dg(i,j,k)-T3dg(i,j,k)(0,1,0)");
 
   29  test_for_zero(t3dg_1(0, 1, 1) - (t3dg_2(0, 1, 1) - t3dg_3(0, 1, 1)),
 
   30                "T3dg(i,j,k)-T3dg(i,j,k)(0,1,1)");
 
   31  test_for_zero(t3dg_1(0, 1, 2) - (t3dg_2(0, 1, 2) - t3dg_3(0, 1, 2)),
 
   32                "T3dg(i,j,k)-T3dg(i,j,k)(0,1,2)");
 
   33  test_for_zero(t3dg_1(0, 2, 0) - (t3dg_2(0, 2, 0) - t3dg_3(0, 2, 0)),
 
   34                "T3dg(i,j,k)-T3dg(i,j,k)(0,2,0)");
 
   35  test_for_zero(t3dg_1(0, 2, 1) - (t3dg_2(0, 2, 1) - t3dg_3(0, 2, 1)),
 
   36                "T3dg(i,j,k)-T3dg(i,j,k)(0,2,1)");
 
   37  test_for_zero(t3dg_1(0, 2, 2) - (t3dg_2(0, 2, 2) - t3dg_3(0, 2, 2)),
 
   38                "T3dg(i,j,k)-T3dg(i,j,k)(0,2,2)");
 
   39  test_for_zero(t3dg_1(1, 0, 0) - (t3dg_2(1, 0, 0) - t3dg_3(1, 0, 0)),
 
   40                "T3dg(i,j,k)-T3dg(i,j,k)(1,0,0)");
 
   41  test_for_zero(t3dg_1(1, 0, 1) - (t3dg_2(1, 0, 1) - t3dg_3(1, 0, 1)),
 
   42                "T3dg(i,j,k)-T3dg(i,j,k)(1,0,1)");
 
   43  test_for_zero(t3dg_1(1, 0, 2) - (t3dg_2(1, 0, 2) - t3dg_3(1, 0, 2)),
 
   44                "T3dg(i,j,k)-T3dg(i,j,k)(1,0,2)");
 
   45  test_for_zero(t3dg_1(1, 1, 0) - (t3dg_2(1, 1, 0) - t3dg_3(1, 1, 0)),
 
   46                "T3dg(i,j,k)-T3dg(i,j,k)(1,1,0)");
 
   47  test_for_zero(t3dg_1(1, 1, 1) - (t3dg_2(1, 1, 1) - t3dg_3(1, 1, 1)),
 
   48                "T3dg(i,j,k)-T3dg(i,j,k)(1,1,1)");
 
   49  test_for_zero(t3dg_1(1, 1, 2) - (t3dg_2(1, 1, 2) - t3dg_3(1, 1, 2)),
 
   50                "T3dg(i,j,k)-T3dg(i,j,k)(1,1,2)");
 
   51  test_for_zero(t3dg_1(1, 2, 0) - (t3dg_2(1, 2, 0) - t3dg_3(1, 2, 0)),
 
   52                "T3dg(i,j,k)-T3dg(i,j,k)(1,2,0)");
 
   53  test_for_zero(t3dg_1(1, 2, 1) - (t3dg_2(1, 2, 1) - t3dg_3(1, 2, 1)),
 
   54                "T3dg(i,j,k)-T3dg(i,j,k)(1,2,1)");
 
   55  test_for_zero(t3dg_1(1, 2, 2) - (t3dg_2(1, 2, 2) - t3dg_3(1, 2, 2)),
 
   56                "T3dg(i,j,k)-T3dg(i,j,k)(1,2,2)");
 
   57  test_for_zero(t3dg_1(2, 0, 0) - (t3dg_2(2, 0, 0) - t3dg_3(2, 0, 0)),
 
   58                "T3dg(i,j,k)-T3dg(i,j,k)(2,0,0)");
 
   59  test_for_zero(t3dg_1(2, 0, 1) - (t3dg_2(2, 0, 1) - t3dg_3(2, 0, 1)),
 
   60                "T3dg(i,j,k)-T3dg(i,j,k)(2,0,1)");
 
   61  test_for_zero(t3dg_1(2, 0, 2) - (t3dg_2(2, 0, 2) - t3dg_3(2, 0, 2)),
 
   62                "T3dg(i,j,k)-T3dg(i,j,k)(2,0,2)");
 
   63  test_for_zero(t3dg_1(2, 1, 0) - (t3dg_2(2, 1, 0) - t3dg_3(2, 1, 0)),
 
   64                "T3dg(i,j,k)-T3dg(i,j,k)(2,1,0)");
 
   65  test_for_zero(t3dg_1(2, 1, 1) - (t3dg_2(2, 1, 1) - t3dg_3(2, 1, 1)),
 
   66                "T3dg(i,j,k)-T3dg(i,j,k)(2,1,1)");
 
   67  test_for_zero(t3dg_1(2, 1, 2) - (t3dg_2(2, 1, 2) - t3dg_3(2, 1, 2)),
 
   68                "T3dg(i,j,k)-T3dg(i,j,k)(2,1,2)");
 
   69  test_for_zero(t3dg_1(2, 2, 0) - (t3dg_2(2, 2, 0) - t3dg_3(2, 2, 0)),
 
   70                "T3dg(i,j,k)-T3dg(i,j,k)(2,2,0)");
 
   71  test_for_zero(t3dg_1(2, 2, 1) - (t3dg_2(2, 2, 1) - t3dg_3(2, 2, 1)),
 
   72                "T3dg(i,j,k)-T3dg(i,j,k)(2,2,1)");
 
   73  test_for_zero(t3dg_1(2, 2, 2) - (t3dg_2(2, 2, 2) - t3dg_3(2, 2, 2)),
 
   74                "T3dg(i,j,k)-T3dg(i,j,k)(2,2,2)");