Mappings and Functions
Tim Denvir · 1986
Sets alone are of limited use. We need ways of associating sets together. This can be done yz means of mappings, functions and relations. The terms ‘function’ and ‘mapping’ are usually used synonymously by mathematicians to denote the same concept. When one represents this concept in programming languages, one normally finds that a distinction arises between two kinds of function or mapping. One kind is fixed and usually not finite, while the other is ‘variable’ or ‘dynamic’ and usually finite. The first kind is typically ‘represented’, that is implemented, as a program function or procedure, whereas the second kind is typically implemented by means of a variety of program language data structures such as arrays.