Chapter 2.2, Problem 49ES

In 47-50 (a) use the logical equivalences $p\to q=~p\nu q$ and and $P\leftrightarrow q=\left(~p\nu q\right)\Lambda \left(~q\nu p\right)$ to rewrite the given statement for ms without using the symbol $\to$ or $\leftrightarrow$ , statement for ms without using the symbol $\to$ or $\leftrightarrow$ , and (b) use the logical equivalence $\to$ or $\leftrightarrow$ , and (b) use the logical equivalence $p\nu q=~\left(~p\Lambda ~q\right)$ to rewrite each statement form using only A and ~..

$\left(p\to r\right)\leftrightarrow \left(q\to r\right)$