Which one of the following well-formed formulae in predicate calculus is NOT valid?

Question

TuteeHUB · Accepted Answer

NA

TuteeHUB · Answer

(∀x p(x) ⇒ ∀x q(x)) ⇒ (∃x ¬ p(x) ∨ ∀x q(x))

TuteeHUB · Answer

(∃x p(x) ∨ ∃x q(x)) ⇒ ∃x (p(x) ∨ q(x))

TuteeHUB · Answer

∃x (p(x) ∧ q(x)) ⇒ (∃x p(x) ∧ ∃x q(x))

TuteeHUB · Answer

∀x (p(x) ∨ q(x)) ⇒ (∀x p(x) ∨ ∀x q(x))

1.	Which one of the following well-formed formulae in predicate calculus is NOT valid?
A.	(∀x p(x) ⇒ ∀x q(x)) ⇒ (∃x ¬ p(x) ∨ ∀x q(x))
B.	(∃x p(x) ∨ ∃x q(x)) ⇒ ∃x (p(x) ∨ q(x))
C.	∃x (p(x) ∧ q(x)) ⇒ (∃x p(x) ∧ ∃x q(x))
D.	∀x (p(x) ∨ q(x)) ⇒ (∀x p(x) ∨ ∀x q(x))
Answer» E.

Discussion