(mathematics) A function of a complex variable obtained by differentiating the logarithm of a gamma function; the digamma function / (physics) The Schrödinger wave function

(mathematics) A generalization of the indicator function for a fuzzy set which assigns a truth value (0 or 1) to each element.

(mathematics) a meromorphic function

(statistics) Any function used to obtain a set of samples from a given population

(mathematics) Any function, of multiple variables, whose value is independent of the order of the variables, i.e. f(a,b) = f(b,a).

(management) Any secondary business activity that supports the line functions of a business, but does not directly affect customers or profits

(mathematics) Any function whose value is the solution of a quadratic polynomial

(mathematical analysis) Any complex-valued measurable function whose range is finite.

(mathematics, logic) A Boolean function whose value is interpreted as truth or falsity

(mathematics) Any function whose domain is a vector space and whose value is its scalar field