Problem 4. Consider the following predicates P, Q, and R. The domain of all predicates is the set of all positive integers. . P(x) : is even Q(x,y): 7% > Ty R(x, y, z): +y+z Indicate whether each of the following logical expressions is a proposition or a predicate. If the expression is a proposition, give its truth value and show your work. If the expression is a predicate, explain why. 4(a) P(9) 4(b) P(2) 4(c) Py) 4(d) Q(12,2) 4(e) P(13) AQ(12) 4(1) R(1,2,3) P(8)