Rewrite each of these statements so that negations appear only within predicates (that is, so that no negation is outside a quantifier or an expression involving logical connectives). a) ¬∃y∃xp (x, y) b) ¬∀x∃yp (x, y) c) ¬∃y(q(y) ∧ ∀x¬r(x, y)) d) ¬∃y(∃xr(x, y) ∨ ∀xs(x, y)) e) ¬∃y(∀x∃zt (x, y, z) ∨ ∃x∀zu (x, y, z))