dHiHj = [ 0, 75.5 , 65.6, 66.3 ; 
          0, 0, 65.5, 66.5 ; 
          0, 0, 0, 37.5; 
          0, 0, 0, 0 ];
t = dHiHj + dHiHj' ;

H3 = A
H1 = B
H2 = D
H4 = C
