2funktioner

2funktioner is a Swedish term that can refer to several related ideas rather than a single standardized concept. Depending on the context, it may denote a function with two inputs—a binary function—or a design pattern in which two functions work together to achieve a result. The exact meaning is therefore context dependent.

In mathematics, a binary function is a function of two arguments. Formally, f: X × Y → Z takes a pair (x, y) and produces z. Notation f(x, y) is common. Examples include addition f(x, y) = x + y, or a function computing a distance with two coordinates. The study focuses on the domain, codomain, and how the output depends on both inputs; concepts like partial evaluation, symmetry, and associativity may arise.

In computer science, the idea often appears as a function with arity two. In functional programming, two-argument functions can be curried into a chain of single-argument functions: add(x)(y) = x + y. Function composition uses two functions to produce a new one, e.g., h = f ∘ g. Two-function design can also refer to modular patterns where one function validates input and another performs processing, supporting separation of concerns.

In Swedish educational material, 2funktioner may be used when teaching about combining two functions, comparing two different functions, or illustrating the concept of a function of two variables in algebra and analytic geometry.

See also: binary function, arity, currying, function composition.