ABSTRACT
Let E be a topological space and let f : E → R be a function. We shall say that f is of Baire zero class if f is continuous at all points
of E (i.e., f is continuous on E). The family of all continuous functions acting from E into R is usually
denoted by the symbol C(E,R). In accordance with the definition above, we will also use the notation Ba0(E,R) for the same family of functions. Thus, we have
Ba0(E,R) = C(E,R).
