\Opgave 15

maximize
x1 + x2 + x3 + x4 + x5 + x6 + x7 

subject to

x1 + x3 <= 1
x1 + x4 <= 1
x1 + x5 <= 1
x1 + x6 <= 1
x2 + x4 <= 1
x2 + x5 <= 1
x2 + x6 <= 1
x2 + x7 <= 1
x3 + x5 <= 1
x3 + x6 <= 1
x3 + x7 <= 1
x4 + x6 <= 1
x4 + x7 <= 1
x5 + x7 <= 1

\ cut
\ x1 + x2 + x3 + x4 + x5 + x6 + x7 <= 2

bounds

x1 <= 1
x2 <= 1
x3 <= 1
x4 <= 1
x5 <= 1
x6 <= 1
x7 <= 1

\ integer
\ x1 x2 x3 x4 x5 x6 x7

end