disp('Example 1 for Phase I,II')
disp('original problem (P) data with objective row  z  -c'' 0   is: ')
A0=[
1    1 0   1 -2    0
0 1 2 0 1 4
0 0 1 -1 1 1 ]
pause
disp('change to  auxiliary problem (A) with artificial vrbles and new objective row: ')
A1=[
1    0 0   0 0   1  1   0
0 1 2 0 1 1 0 4
0 0 1 -1 1  0 1 1 ]
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_5 leaves' )
A=piv(A,2,2)
pause
disp('x_2 enters basis and x_6 leaves' )
A=piv(A,3,3)
disp('optimal tableau with basis B={1,2}')
pause
disp('initial problem again so pivot to get optimal basis B')
A=A0
disp('x_1 enters basis' )
A=piv(A,2,2)
disp('x_2 enters basis' )
A=piv(A,3,3)
pause
disp('x_3 enters basis and x_1 leaves' )
A=piv(A,2,4)
disp('x_4 enters basis and x_2 leaves' )
A=piv(A,3,5)
