Implementing simplified SOP (sum-of-products) Which universal gate family allows simplified sum-of-products expressions to be realized directly using only that one gate type, generally with little or no increase in circuit complexity?

Introduction / Context:
Practical logic design often targets a single universal gate to simplify procurement, layout, and timing. Knowing how to implement canonical forms such as sum-of-products (SOP) or product-of-sums (POS) using universal gates is foundational for digital design and optimization.

Given Data / Assumptions:

• Simplified SOP expression is available (for example, from Karnaugh map minimization).
• Universal gates: NAND and NOR.
• Goal: use a single type of universal gate with minimal complexity overhead.

Concept / Approach:
NAND gates are functionally complete. Any SOP network (AND terms feeding an OR) can be implemented exclusively with NAND by applying De Morgan's transformations. Specifically, an OR of AND terms can be built with a NAND–NAND structure: first-level NANDs form the product terms (with appropriate input inversions as needed), and a final NAND implements the OR via inversion rules.

Step-by-Step Solution:

Verification / Alternative check:
Compare gate counts: A two-level AND-OR network maps to a two-level NAND-NAND network with similar or fewer total gates and no increase in logic depth for the simplified SOP.

Why Other Options Are Wrong:

• NOR: More natural for POS implementations (OR-AND dual), not SOP.
• AND/OR and OR/AND: These are not universal single-gate families; they describe mixed-gate two-level forms.

Common Pitfalls:
Forgetting to manage signal inversion at outputs of NAND stages; misapplying De Morgan's laws leading to unintended polarity.

Final Answer:
NAND