## Discrete Mathematics with Applications 4th Edition

The negation of "if p then q" is logically equivalent to "p and not q:" ~(p $\rightarrow$ q) $\equiv$ p $\land$ ~q. For sentences involving AND or OR, recall De Morgan's Laws: The negation of AND: ~(p $\land$ q) $\equiv$ ~p$\lor$ ~q The negation of OR: ~(p $\lor$ q) $\equiv$ ~p$\land$ ~q