Let p, q, r be boolean variables and let U be the universe consisting of all propositional formulas in variables 11, q, 1'. That is, U consists of all valid formulas using any of the symbols p, q, r, 0, 1,-I, V, A, => , 4:) ,(,). Forexample,p => (p 4:) q) andpA (-IqA r) are elements of U. Define the following subsets of U: 0 A consists of all formulas f such that f evaluates to 1 in at least 4 rows of its truth table, 0 B consists of all formulas f such that the formula f V p is a tautology. Prove or disprove each of the following: 1.AB 2.BA