Let T be an arbitrary tautology and be an arbitrary contradiction. Show that the following are logically equivalent. 1. (pq)(qp) 2. (p(qr))((pq)(pr)) 3. (p) 4. (pq)((pq)p) Exercise 5 Show that the following formulas are tautologies. 1. (pp) 2. (((pq)q)p) 3. ((pp)p) 4. (p(q(qp)))