(biology) Any function of the body that is essential for maintaining life, especially breathing and circulation.

(mathematics) A function whose range is a subset of the set of real numbers.

(mathematics) A function whose range is a subset of the set of complex numbers.

(mathematical analysis) A function which is equal to 1 for all points in its domain which belong to a given set, and is equal to 0 for all points in the domain which do not belong to that given set.

(mathematical analysis) A function which is Borel measurable.

plural of simple function

plural of cubic function

plural of composite function

plural of constant function

plural of even function