nonvariables

Nonvariables are quantities that do not vary within a given context. In mathematics and related disciplines, a nonvariable is a constant or fixed parameter that remains unchanged during the evaluation of an expression or a model. This term contrasts with variables, symbols that can assume different values depending on input, conditions, or time.

Nonvariables appear in several settings. In algebra, constants and constant terms are nonvariables; for example, in the polynomial f(x) = 3x + 7, the numbers 3 and 7 are nonvariables because neither depends on x. In a linear model such as y = ax + b, if a and b are fixed numbers chosen before evaluation, they function as nonvariables; if instead a or b is allowed to vary, they become variables.

In programming and computer science, nonvariables include literals and fixed values that do not change during a program's execution, distinguishing them from variables that store data which can be reassigned. In logic and formal systems, constants play a role analogous to nonvariables, serving as fixed symbols with a single interpretation within a given theory or model.

Notes: Nonvariable is not always used as a formal technical term in standard textbooks; it is often used informally to emphasize the distinction between fixed quantities and variables.

See also: variable, constant term, parameter, literal, constant (mathematics).