EXERCISE $1\mathrm{.}1\mathrm{.}13$ Mimic the manipulation in $(1\mathrm{.}7)$ to show that not$(pvvqvvr)$ is logically equivalent to $not{p}^{{?}^{?}}not{q}^{{?}^{?}}$notr.

EXERCISE $1\mathrm{.}1\mathrm{.}14$ Use DeMorgan's laws and symbolic manipulation to show