Aditivní

Aditivní is an adjective used in Czech to describe something that is additive, that adds or contributes something extra. The term is used across disciplines to denote a property, operation, or substance that increases or combines with other parts in an additive way. It is commonly contrasted with multiplicative or subtractive notions.

In mathematics, an additive object satisfies a rule of additivity. For a function f, this means f(x + y) = f(x) + f(y) for all x and y in its domain. Such functions are called additive functions. Linear functions f(x) = cx are additive, and, under certain regularity conditions, every additive function on the real numbers is linear; without those conditions, more exotic additive functions exist. In measure theory, an additive set function μ satisfies μ(A ∪ B) = μ(A) + μ(B) for disjoint sets A and B. When a set function is defined on a σ-algebra and is countably additive, it becomes a measure, and a probability measure is a measure with total mass 1.

In everyday usage, aditivní also describes substances added to other materials to achieve desired effects. Aditivní látky are additives used in foods for flavor, texture, preservation, or appearance; in fuels and cosmetics, they serve similar purposes. Such substances are typically regulated and must be identified on product labeling.

Etymology traces to Latin additivus, meaning “that which is added.” The concept of additivity appears in many fields, reflecting a common idea that the whole reflects the sum of its parts.