evaluable

Evaluable is an adjective meaning capable of being evaluated. In fields such as mathematics, logic, and computer science, it is used to describe expressions, terms, or propositions whose value or truth can be determined according to a given set of rules.

In mathematics, an expression like 3 × (4 + 2) is evaluable and simplifies to 18. An expression with a free variable, such as x + 1, is evaluable as a function, but not to a single number until x is specified. Expressions may be non-evaluable if they involve undefined operations (for example, division by zero) or if they contain objects outside the intended domain.

In programming and logic, evaluability is tied to the language's evaluation semantics. An expression is evaluable if it reduces to a result without ambiguity. Some languages support partial evaluation or lazy evaluation, where only the necessary parts are evaluated. Problems such as non-termination or side effects can affect evaluability, making some expressions effectively non-evaluable in a given context.

Etymology and related terms: the word derives from evaluate, from Latin valēre meaning "to be worth" or "to be strong," with the English -able suffix forming evaluable. Related concepts include evaluation, evaluative, and partial evaluation.