For any statements p, q, prove that (a) ¬ (p ↑

For any statements p, q, prove that
(a) ¬ (p ↑ q) ⇔ (¬ p ↑ ¬ q)
(b) ¬(p ↑ q) ⇔ (¬ p ↑ ¬ q)