1. ∼A ≡ B

question 43

Multiple Choice

1. ∼A ≡ B
2. A • ∼C
-Which of the following propositions is an immediate (one-step) consequence in PL of the given premises?

• A) ∼(A ≡ B)
• B) B ≡ ∼A
• C) ∼∼A ≡ ∼B
• D) Options A, B, and C
• E) Options A and B, but not option C

---

Definitions:

Mesoderm

The middle layer of an embryo in multicellular organisms, giving rise to muscles, bones, and the circulatory system among other structures.

Water-Vascular System

A network of hydraulic canals unique to echinoderms, such as starfish, used for locomotion, feeding, and respiration.

Exoskeleton

External skeleton of some invertebrates; hard external parts that muscles attach to and move.

Shed

To cast off or discard something, such as skin or hair, through a natural process or to describe a simple, single-story structure used for storage.