質問: ¬(p ⇒ q) and p ∧ ¬q show that the following pairs of propositions are logically equivalent.
回答: the given left side is not (p --> q) = not ( not p or q) = <-- implication identity p and not q <-- demorgan's lawwhich is the right sidenow by truth table=========================================== p q ~q p->q left side right side t t f t f f t f t f t t f t f t f f f f t t f f