( P AND Q ) AND ( ~ P OR ~ Q ) AND ( P AND Q ) AND ( ~ P OR Q )
Is this a contradiction?
Work: Well, lol, I got it is a contradiction. There is always one false in each row. So I assume it is a contradiction.
( P AND Q ) AND ( ~ P OR ~ Q ) AND ( P AND Q ) AND ( ~ P OR Q )
Is this a contradiction?
Work: Well, lol, I got it is a contradiction. There is always one false in each row. So I assume it is a contradiction.