  Let $S$ be a symmetric linear relation in the Pontyagin space $\left(
\mathcal{K},\, \left[ .,. \right] \right)$ and let $\Pi=\left(
\mathcal{\mathcal{H}}, \Gamma_{0}, \Gamma_{1} \right)$ be the corresponding
boundary triple. We prove that the corresponding Weyl function $Q$ satisfies
$Q\in N_{\kappa }(\mathcal{H})$. Conversely, for regular $Q\in N_{\kappa
}(\mathcal{H})$, we find linear relation $S \subsetneq A$, where $A$ is
representing self-adjoint linear relation of $Q$, and we prove that $Q$ is the
Weyl function of the relation $S$. We also prove $\hat{A}=\ker \Gamma_{1}$,
where $\hat{A}$ is the representing relation of the $\hat{Q}:=-Q^{-1}$. In
addition, if we assume that the derivative at infinity $Q^{'}\left( \infty
\right):=\lim \limits_{z \to \infty}{zQ(z)}$ is a boundedly invertible operator
then we are able to decompose $A$, $\hat{A}$ and $S^{+}$ in terms of $S$, i.e.
we express relation matrices of $A$, $\hat{A}$ and $S^{+}$ in terms of $S$,
which is a bounded operator in this case.
