Prove that the following statement pattern is a contradiction.
(p ∧ q) ∧ (~p ∨ ~q)
SOLUTION
| p | q | ~p | ~q | p∧q | ~p∨~q | (p∧q)∧(~p∨~q) |
| T | T | F | F | T | F | F |
| T | F | F | T | F | T | F |
| F | T | T | F | F | T | F |
| F | F | T | T | F | T | F |
All the truth values in the last column are F. Hence, it is a contradiction.
