2. (5 points) A statement is in prenex normal form (PNF) if and only if it is of the form where each Qi, i = 1, 2, . . . , k, is either an existential quantifier or a universal quantifier, and P(xi, . . . , a is a predicate involving no quantifiers. For example,3x Vy(P(z, y) Q(y)) is in PNF, but r P(z) v yx Q(x) is not. For each logical statement below, give a logically equivalent statement that is in PNF (b) 3r P(x)Vr Q(x)