$\st^{*}[h,k]=\overline{\st[k,h]}$, $h,k \in \dom \st$; for the diagonal of $\st$ the notation $\st[\cdot]$ will be used. A (sesquilinear) form is said to be sectorial with vertex at the origin and semi-angle $\alpha$, $\alpha \in [0,\pi/2)$, if $$\label{sec}
 |\st_{\I} [h]|  \le  (\tan \alpha) \, \st_{\r} [h],
 \quad
 h \in \dom \st,$$ where the real part $\st_{\rm r}$ and the imaginary part $\st_{\I}$ are defined by $$\label{secc}
\st_{\rm r}=\frac{\st+\st^{*}}{2}, \quad \st_{\rm i}=\frac{\st-\st^{*}}{2i},
\quad \dom \st_{\rm r}=\dom \st_{\I}=\dom \st.$$ A sesquilinear form will be called a form in the rest of this note. Observe that the form $\st_{\rm r}$ is nonnegative and that the form $\st_{\rm i}$ is symmetric, while $\st=\st_{\rm r}+i\,\st_{\rm i}$. A sectorial form $\st$ is said to be *closed* if $$h_n \to h, \quad \st[h_n-h_m] \to 0 \quad \Rightarrow \quad
h \in \dom \st \quad \mbox{and} \quad \st[h_n-h] \to 0.$$ A sectorial form $\st$ is closed if and only if its real part $\st_r$ is closed; see [@Kato].

The connection between maximal sectorial relations and closed sectorial forms is given in the so-called first representation theorem; cf. [@Ar96], [@HSSW17], [@Kato], [@RB90].

\[s-first\] Let $\st$ be a closed sectorial form in a Hilbert space $\sH$ with vertex at the origin and 