> functions as values in Mathematics just isn't considered as "normal" outside of fields concerned with the fundamental basis of mathematics. It seems to be fa

> functions as values in Mathematics just isn't considered as "normal" outside of fields concerned with the fundamental basis of mathematics. It seems to be fairly common in linear algebra. The usual way to represent a linear function is as a matrix, and a function on that matrix is a function on a function. You also get fields of polynomials, in which differentiation is a linear operator.