In: Advanced Math
Give a proof or counterexample, whichever is appropriate.
1. NOT (∃x, (P(x) OR Q(x) OR R(x))) is logically equivalent to ∀x, ((NOT P(x)) AND (NOT Q(x)) AND (NOT R(x))).
2. NOT (∃x, (P(x) AND Q(x) AND R(x))) is logically equivalent to ∀x, ((NOT P(x)) OR (NOT Q(x)) OR (NOT R(x))).
3. NOT (∃x, (P(x) ⇒ Q(x))) is logically equivalent to ∀x, (P(x)⇒ NOT Q(x)).
4. NOT (∃x, (P(x) ⇒ Q(x))) is logically equivalent to ∀x, (P(x) AND (NOT Q(x))).
5. ∃x, (P(x) OR Q(x)) is logically equivalent to (∃x, P(x)) OR (∃x, Q(x)).
6. ∃x, (P(x) AND Q(x)) is logically equivalent to (∃x, P(x)) AND (∃x, Q(x)).
7. ∀x, (P(x) OR Q(x)) is logically equivalent to (∀x, P(x)) OR (∀x, Q(x)).
8. ∀x, (P(x) AND Q(x)) is logically equivalent to (∀x, P(x)) AND (∀x, Q(x)).
9. ∀x, (P (x) ⇒ Q(x)) is logically equivalent to (∀x, (x)) ⇒ (∀x, Q(x)).