Boolean forms refresher (SOP vs POS): In digital logic simplification, a sum-of-products (SOP) Boolean expression is formed by ORing together two or more product terms (each product term is an AND of literals). The statement that SOP “describes the ANDing of two or more OR functions” is being evaluated—does that accurately define SOP?

Introduction / Context:
Sum-of-products (SOP) and product-of-sums (POS) are the two canonical ways to write Boolean expressions used for logic design and simplification. Many exam questions test whether you can distinguish SOP from POS because mixing them up leads to wrong gate-level implementations (AND–OR vs OR–AND structures). The prompt claims SOP is “the ANDing of two or more OR functions.” We will evaluate this definition precisely.

Given Data / Assumptions:

• SOP means “sum” (OR) of “products” (ANDed literals).
• A product term is an AND of one or more literals (e.g., A·B·C’).
• POS means “product” (AND) of “sums” (ORed literals).
• Literals may be complemented or uncomplemented without changing the form classification.

Concept / Approach:
By definition, SOP is built by ORing several product terms: Y = P1 + P2 + P3, where each Pi is an AND of literals. Conversely, POS is built by ANDing several sum terms: Y = S1 · S2 · S3, where each Si is an OR of literals. Thus the statement in the stem swaps these: it describes POS, not SOP. Correct identification ensures you choose the right two-level gate structure (AND–OR for SOP, OR–AND for POS).

Step-by-Step Solution:

Verification / Alternative check:
Write a small example. SOP example: Y = A·B + A’·C. POS example: Y = (A + B)·(A’ + C). Implementations correspond to AND–OR (SOP) vs OR–AND (POS) at the gate level—another confirmation of the definitions.

Why Other Options Are Wrong:
“Correct” directly contradicts the standard definition. The other choices introduce conditions (single variable, De Morgan, literal polarity) that do not change how SOP/POS are defined.

Common Pitfalls:
Confusing the spoken order: “sum of products” means OR of ANDs, while “product of sums” means AND of ORs. Also, believing complements change the form—they do not.

Final Answer:
Incorrect