Core Boolean operations: Identify the choice that is NOT one of the three basic Boolean operations used to build digital logic.

Introduction / Context:
Digital logic is constructed from a small set of primitive Boolean operations. Mastery of these operations—AND, OR, and NOT—enables the design and analysis of combinational and sequential circuits, as well as simplification with Boolean algebra and Karnaugh maps.

Given Data / Assumptions:

• The three elemental operations are being considered.
• We are asked to spot the item that is not a Boolean primitive.
• Terminology follows standard digital electronics convention.

Concept / Approach:
Boolean algebra is defined over binary variables using AND (·), OR (+), and NOT (inversion). While many other useful operations exist (XOR, NAND, NOR), they are derived from the three basics. The word “FOR” is simply an English preposition, not a Boolean operator.

Step-by-Step Reasoning:
List standard primitives: AND, OR, NOT.Compare each option to the set: OR ✓, NOT ✓, AND ✓, FOR ✗.Therefore, the non-Boolean item is FOR.

Verification / Alternative check:
Consider functional completeness: NAND or NOR alone can implement all three basics, further confirming that Boolean logic relies on AND/OR/NOT at its foundation, not an operator named “FOR.”

Why Other Options Are Wrong:

• OR, NOT, AND are indeed basic Boolean operations and appear in every introductory logic text and IC family datasheet.

Common Pitfalls:

• Confusing XOR with a basic primitive. XOR is fundamental in practice but is algebraically derived from AND, OR, and NOT.
• Assuming natural-language words map to logic terms; only specific defined operators are used.

Final Answer:
FOR