What expression is spoken concerning logic symbols when working with two variables?

The correct expression spoken concerning logic symbols when working with two variables is "X and Y Quantity NOT." This expression is commonly used in the context of logical operations, specifically when referring to the logical NOT operation applied to the conjunction of two variables, X and Y.

In logic, the term "Quantity NOT" implies the negation of a combined logical statement or operation. This phrase suggests that we are taking the result of the operation involving both variables (in this case, the AND operation between X and Y) and then inverting that result. The AND operation requires that both variables must be true for the entire statement to be true, while the NOT operation negates the result.

This understanding forms a fundamental part of digital logic and Boolean algebra, where manipulations of variables using logical symbols are essential for designing circuits and understanding logical propositions.