If there exist infinitely many non negative terms in a sequence, can we say that $\lim \sup \geq 0 $?
Actually I'm trying to understand a proof of "$\lim \sup \sqrt[\leftroot{-2}\uproot{2}\ n]{|a_n|} < 1 $ Then the series $ \sum |a_n|$ convegres" and in the proof it is written that $\lim \sup \geq 0$. So naturally, this question arises.