funktioon

Funktioon is a theoretical construct used in discussions of functional abstraction in mathematics and computer science. The term is not standardized in established sources but is sometimes employed in instructional or speculative contexts to denote an idealized function-like operation.

Definition and scope: A funktioon is an abstract mapping that assigns to each input from its domain a single output in its codomain. Like a mathematical function, it may have a defined domain, a codomain, and a rule that specifies the output. In programming-related usage, a funktioon is treated as a first-class value that can be stored, passed as an argument, and returned from other functions. It supports composition: if f and g are funktioon, then the composition f ∘ g is itself a funktioon.

Properties: In pure contexts, funktioon is deterministic and referentially transparent; its evaluation depends only on its input. Variants may be partial (not defined for all inputs) or include side effects when used in effectful programming models. The concept emphasizes immutability and predictable composition.

Examples: A square funktioon maps x to x*x; an add3 funktioon maps x to x+3. The composition square ∘ add3 maps x to (x+3)^2. In education, funktioon is often used as a neutral stand-in for a function to illustrate composition, higher-order functions, and currying.

See also: Function, Higher-order function, Function composition, Pure function, Mapping.