Which of the following statements are logically equivalent?
(A) Some animals are birds.

(B) Some birds are animals.

(C) Some animals are not non-birds.

(D) Some animals are non-birds.

(E) Some non-birds are not non-animals.

Choose the most appropriate answer from the options given below:

Correct option is A

The statements (A) Some animals are birds, (B) Some birds are animals, and (C) Some animals are not non-birds are logically equivalent. They all express the same relationship between birds and animals.
· (A) and (B) are simple rephrasings of each other using the commutative property of “some” (they describe the same relationship in reverse order).
· (C), “Some animals are not non-birds,” is a double negative, which simplifies to “Some animals are birds,” making it logically equivalent to (A) and (B).
· However, (D) and (E) are not logically equivalent to these statements, as they introduce different relationships about “non-birds.”
Information Booster:
1. Logical Equivalence: Two statements are logically equivalent if they imply each other.
2. Double Negation: Statement I uses a double negative, which simplifies to the same meaning as (A) and (B).
3. Commutative Property: In categorical logic, “Some A are B” is logically equivalent to “Some B are A.”