MINIMIZE
obj: - 2 x3
SUBJECT TO
c1: + x2 - x1 <= 10
c2: + x3 + x2 + x1 <= 20
BOUNDS
2.1 <= x1 <= 30
0 <= x2 <= +inf
2 <= x3 <= 3
GENERALS
x1 x3
SEMI-CONTINUOUS
x1 x3
END