Issue with correctness

[NathanDang97]

Hi,

I think I have noticed a slight bug in terms of the correctness of the truth-table computation. Attached image is an example. Specifically, the last row of the truth-table should be evaluated to 0, i.e. since the last clause is evaluated to 0 and thus by the nature of logical-and, the formula should be evaluated to 0 under that specific assignment.