Examine whether the following statement pattern is a tautology, a contradiction or a contingency.
(p ∧ ~ q) → (~ p ∧ ~ q)
SOLUTION
| p | q | ~p | ~q | p∧~q | ~p∧~q | (p∧~q)→(~p∧~q) |
| T | T | F | F | F | F | T |
| T | F | F | T | T | F | F |
| F | T | T | F | F | F | T |
| F | F | T | T | F | T | T |
The truth values in the last column are not identical. Hence, it is contingency.
