1. The problem statement, all variables and given/known data This is an exercise from 'How to Prove it - A Structured Approach' (Exercise 7a, page 54) . So far a a really great book. 2. Relevant equations The DeMorgan, Absorption, Idempotent, Double Negation, Commutative, Associative, Distributive, Tautology, Contradiction, Conditional and Contrapositive law is what the book has gone through so far. 3. The attempt at a solution I have been banging my head at this for hours. Constructing a truth table is trivial. But i havent been able to go from one formula to the other by use of the stated laws. All exercises up to this have just required a few applications of the laws. So all my attempts at solving this so far have been mostly pages of jumping between formulas using the applicable laws. I really feel like im missing something. So any help would be greatly appreciated!