! Mar2007 Wolsey, 1998, John Wiley (book from ISEG/UTL)
! 7.3 "Branch and bound: an example", p 95
! z_max = 7; X = (2, 1)

MAX 4 x1 - x2
SUBJECT TO
7.2) 7 x1 -2 x2 <= 14
7.3)         x2 <= 3
7.4) 2 x1 -2 x2 <= 3
END
! Now, the first {no. of} variables are integer
GIN 2
! GIN x1
! GIN x2