"Nu este nimeni în bibliotecă."

Translation: There is nobody in the library.

[Lng52-._]

I suppose you can also say, "There is no one in the library".

[AmadeusMinu]

There isnt anybody in the library

[Pyropunk]

Why the double negative?

[manuna84]

That's quite common for Slavic languages, and I believe for Spanish too. It is not boolean logic :)

[Yevhen381991]

No hay nadie - double negative in Spanish
Никого нет (to nobody is not) - double negative in Russian