Are there general methods that can be applied when using the Borel-Cantelli Lemma, to get a statement about a sequence of random variables?
Revision of Borel-Cantelli, $(X_n)_{n \geq 1}$ sqn of $\geq 0$ identical RVs with $E(X) < \infty$ then $X_n/n \to 0$ a.s., are my arguments correct?