Consider the universe of all subsets of the set A = {a, b, c}. Let the variables x and y denote subsets of A. Find the truth value of each of the statements, and explain your answer. If the statement is false, give a counterexample.
(a) (x (y [x ⊆ y]
(b) (x (y [(x ⊆ y) ˅ (y ⊆ x)]
(c) ∃x (y [x ⊆ y]
(d) (x ∃y [x ⊆ y]