ABSTRACT
This chapter is concerned with the definition of the limit of a function as the argument approaches a given value, and also with the definition of what is meant by a “continuous function.” Limits and continuity of functions, in works on ordinary mathematics, are defined in terms involving number. Many functions are discontinuous for one or several values of the variable, but continuous for all other values. The actual fact is that, though continuous functions are more familiar, they are the exceptions: there are infinitely more discontinuous functions than continuous ones. A function is continuous at a point where its value is the same as the limit of its values for approaches either from above or from below.
