Solution
= Solution
Monotone convergence gives $\int F=\sum_k2^k\lambda(E_k)$. Since $F\le f\le2F$, $f$ is integrable exactly when this <series> is finite.
= Solution
Monotone convergence gives $\int F=\sum_k2^k\lambda(E_k)$. Since $F\le f\le2F$, $f$ is integrable exactly when this <series> is finite.