Which one of the following predicate formulae is NOT logically valid?Note that W is a predicate formula without any free occurrence of x.

Question

TuteeHUB · Accepted Answer

Ǝx(p(x) → W) ≡ ∀x p(x) → W

TuteeHUB · Answer

∀x(p(x) ∨ W) ≡ ∀x p(x) ∨ W

TuteeHUB · Answer

Ǝx(p(x) ∧ W) ≡ Ǝx p(x) ∧ W

TuteeHUB · Answer

∀x(p(x) → W) ≡ ∀x p(x) → W

1.	Which one of the following predicate formulae is NOT logically valid?Note that W is a predicate formula without any free occurrence of x.
A.	∀x(p(x) ∨ W) ≡ ∀x p(x) ∨ W
B.	Ǝx(p(x) ∧ W) ≡ Ǝx p(x) ∧ W
C.	∀x(p(x) → W) ≡ ∀x p(x) → W
D.	Ǝx(p(x) → W) ≡ ∀x p(x) → W
Answer» D. Ǝx(p(x) → W) ≡ ∀x p(x) → W

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