This message of warning appears at the line 967, which says:
\begin{enumerate}
\item Dac\u{a} $(a_{n})_{n \geq 1} \subseteq D$ este un \c{s}ir cu $\lim_{n \to \infty} a_{n} \in D$, atunci $\lim_{n \to \infty} f(a_{n}) = f(\lim_{n \to \infty}a_{n})$, adic\u{a} o func\c{t}ie continu\u{a} comut\u{a} cu limite de \c{s}iruri.
\end{enumerate}
In the log file:
underfull \hbox (badness 1173) in paragraph
