10. Let P(x) and Q(x) be predicates and let D = {a, b}. Use the expand method to show that x(P(x) ( yQ(y))) xy(P(x) Q(y)) You can use replacement rules for connectives but not for quantifiers.

11. Let P(x, y) be a predicate. Specify a domain and give an argument to show that in general xyP(x, y) 6 yx P(x, y)