disp('Example 2 Phase I,II ')
disp('original problem (P) data with objective row  z  -c'' 0     is: ')
A0=[
1   -1 0   0  0    0
0 3 5 2 -1 7
0 2 5  3 1 3 ]
pause
disp('change to  auxiliary problem (A) with artificial vrbles and new objective row: ')
A1=[
1    0 0   0 0   1  1   0
0 3 5 2 -1 1 0 7 
0 2 5  3 1 0 1 3  ]
disp('pivot on x_5 and then x_6 ' )
pause
A=A1;
A=piv(A,2,6)
A=piv(A,3,7)
pause
disp('x_1 enters basis and x_6 leaves' )
A=piv(A,3,2)
disp('Optimal tableau with w^*<0 implies INFEASIBLE(P)')
