Which of the following statements is a tautology?
(1) ~(p ∨ ~q) → p ∨ q
(2) ~(p ∧ ~q) → p ∨ q
(3) ~(p ∨ ~q) → p ∧ q
(4) p ∨ (~q) → p ∧ q
Answer is (1) ~(p ∨ ~q)→p ∨ q
