I'm studying Infinitely Divisible random variables using this [Lecture Notes][1]. And I have a question that is driving me crazy. In the proof of the "only if" part of the **Levy-Khintchine representation** (Theorem 5.3), the **Theorem 5.13** contains an essential step. In this Theorem 5.13, the truncation function $h'$ must satisfy conditions (\ref{hhdjj}): \begin{equation}\label{hhdjj}\tag{5.4} h'(x)=1+o(|x|) \quad as\quad |x|\to 0\quad \hbox{ and }\quad h'(x)=O(1/|x|), \quad as \quad x\to\infty. \end{equation} However, in the proof of the "only if" part of the Theorem 5.3 (**page 17**), They approximate $\rho$ by a sequence of Compound Poisson random variables $\rho_n$ whose triple Levy-Khintchine representation and the use of Theorem 5.13 are described in the following print (Bottom of page 17): [![enter image description here][3]][3] So my big question is that they can't use Theorem 5.13 directly because $h\equiv 0$ doesn't satisfy the first condition in (\ref{hhdjj}). Am I making a faux pas by reading the notes? I appreciate your help. [1]: https://actuarweb.aegean.gr/levy2019/uploads/1/1/5/5/115582233/baurdoux_papapantoleon_levyprocesses.pdf [3]: https://i.sstatic.net/FhN1F.png