Function Arity

Overview

Function arity describes the number of parameters that a function takes.

Arity

Arity refers to the number of arguments in a function.

• Unary
  {% f(x) %}
• Binary A two place function is a function with two variables.
  {% f(x_1,x_2) %}
  Binary functions form the core of algebra. (The common examples of binary functions being addition and multiplication).
• N-Arity
  {% f(x_1,x_2, ... ,x_n) %}

Equivalences

In computer science, n-arity functions are often recast as unary functions in one of two ways

• as a function of a single ordered pair
• as a curried function

By recasting all functions as unary functions, the space of functions and types over which the functions operate becomes a category.