15    return a(1, 0, 0, 1) * b(1, 0, 0, 1) + 
a(2, 0, 0, 1) * b(2, 0, 0, 1)
 
   16           + 
a(0, 1, 0, 1) * b(0, 1, 0, 1) + 
a(2, 1, 0, 1) * b(2, 1, 0, 1)
 
   17           + 
a(0, 2, 0, 1) * b(0, 2, 0, 1) + 
a(1, 2, 0, 1) * b(1, 2, 0, 1)
 
   18           + 
a(1, 0, 0, 2) * b(1, 0, 0, 2) + 
a(2, 0, 0, 2) * b(2, 0, 0, 2)
 
   19           + 
a(0, 1, 0, 2) * b(0, 1, 0, 2) + 
a(2, 1, 0, 2) * b(2, 1, 0, 2)
 
   20           + 
a(0, 2, 0, 2) * b(0, 2, 0, 2) + 
a(1, 2, 0, 2) * b(1, 2, 0, 2)
 
   21           + 
a(1, 0, 1, 0) * b(1, 0, 1, 0) + 
a(2, 0, 1, 0) * b(2, 0, 1, 0)
 
   22           + 
a(0, 1, 1, 0) * b(0, 1, 1, 0) + 
a(2, 1, 1, 0) * b(2, 1, 1, 0)
 
   23           + 
a(0, 2, 1, 0) * b(0, 2, 1, 0) + 
a(1, 2, 1, 0) * b(1, 2, 1, 0)
 
   24           + 
a(1, 0, 1, 2) * b(1, 0, 1, 2) + 
a(2, 0, 1, 2) * b(2, 0, 1, 2)
 
   25           + 
a(0, 1, 1, 2) * b(0, 1, 1, 2) + 
a(2, 1, 1, 2) * b(2, 1, 1, 2)
 
   26           + 
a(0, 2, 1, 2) * b(0, 2, 1, 2) + 
a(1, 2, 1, 2) * b(1, 2, 1, 2)
 
   27           + 
a(1, 0, 2, 0) * b(1, 0, 2, 0) + 
a(2, 0, 2, 0) * b(2, 0, 2, 0)
 
   28           + 
a(0, 1, 2, 0) * b(0, 1, 2, 0) + 
a(2, 1, 2, 0) * b(2, 1, 2, 0)
 
   29           + 
a(0, 2, 2, 0) * b(0, 2, 2, 0) + 
a(1, 2, 2, 0) * b(1, 2, 2, 0)
 
   30           + 
a(1, 0, 2, 1) * b(1, 0, 2, 1) + 
a(2, 0, 2, 1) * b(2, 0, 2, 1)
 
   31           + 
a(0, 1, 2, 1) * b(0, 1, 2, 1) + 
a(2, 1, 2, 1) * b(2, 1, 2, 1)
 
   32           + 
a(0, 2, 2, 1) * b(0, 2, 2, 1) + 
a(1, 2, 2, 1) * b(1, 2, 2, 1);