Abstract: | The following problem is considered. Given a real-valued function f defined on a topological space X, when can one find a countable familyf n :n∈ω of continuous real-valued functions on X that approximates f on finite subsets of X? That is, for any finite set F?X and every real number ε>0 one can choosen∈ω such that ∥f(x)?fn(x)∥<ε for everyx∈F. It will be shown that the problem has a positive solution if and only if X splits. A space X is said to split if, for any A?X, there exists a continuous mapf A:X→R ω such that A=f A ?1 (A). Splitting spaces will be studied systematically. |