x_{3}(k)  x_{1}(k + 1) 
 x_{1}(k)  x_{3}(k)  x_{2}(k + 1) 
 x_{1}(k)  x_{2}(k)  x_{3}(k + 1) 
0  0 
 0  0  0 
 0  0  1 
1  1 
 0  1  0 
 0  1  0 


 1  0  1 
 1  0  1 


 1  1  0 
 1  1  1 