Let f R*[a, g] for all > a. Show that f R*[a, ] if

Let f ∈ R*[a, g] for all γ > a. Show that f ∈ R*[a, ∞] if and only if for every ε > 0 there exists K(ε) > a such that if q > p > K(ε), then |∫qp f| < ε.