* #variable= 5 #constraint= 4
*
* this is a dummy instance
*
1 x1 +4 x2 -2 x5 >= 2;
-1 x1 +4 x2 -2 x5 >= +3;
12345678901234567890 x4 +4 x3 >= 10;
* an equality constraint
2 x2 +3 x4 +2 x1 +3 x5 = 5;