Exercise 2.32 (Monotone Functions). For which value of n are the following functions monotone?

1 f1(x1, . . . , xn) = x1x2 ∨ x1x3 ∨ · · · xn−1xn (the disjunctions of all conjunctions consisting of two non-negated variables);

2 f2(x1, . . . , xn) = x1x2 . . . xn−1xn → (x1 ⊕ x2 ⊕· · ·⊕xn−1 ⊕ xn).