Which of the following is true?
p⇒q≡∼p⇒∼q
~(p⇒∼q)≡∼p∧q
~(~p⇒∼q)≡∼p∧q
~(~p⇔q)≡[~(p⇒q)∧~(q⇒p)]
~(p⇒q)≡p∧~q∴ ~(~p⇒∼q)≡∼p∧~(~q)≡∼p∧q Thus, ~(~p⇒∼q)≡∼p∧q