The one place for your designs
To enable design management, you'll need to meet the requirements. If you need help, reach out to our support team for assistance.
Incorrect answer with PB Solver
I am seeing a strange issue with solving a PBO problem using SAT4J: version NIGHTLY.v20151101
Attached are 2 opb files: min-nonbuggy.opb and min.opb
Differences between the files: Both files differ from line 18 onwards. "min.opb" is an extension of min-nonbuggy.opb. Note that both files have same objective function that needs to be minimized.
The first file ("min-nonbuggy.opb") returns correct answer with optimum value as "4" with x12=0, x14 = 0 and x17=0. I agree with this answer. I also verified this by manually solving the constraints and objective function.
The second file ("min.opb") returns answer with optimum value as "5" with x12=1, x14=0 and x17=0. I think this is wrong.
(I am interested in values that appear in objective function only)
This is quite surprising given that - no additional constraint involving "x12" appears in "min.opb". So x12 should be 0 regardless of value of x17. Isn't it? Why is the answer returned as x12=1?