Chapter 1.3, Problem 9E

For each of these compound propositions, use the conditional-disjunction equivalence (Example 3) to find an equivalent compound proposition that does not involve conditionals.

a) $\neg p\to \neg q$

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

c) $\left(\neg q\to p\right)\to \left(p\to \neg q\right)$