\begin{equation}
\label{appex:eq-root-h-node-1}
\begin{split}
       P(H_k^{}|Pa(H_k^{})) &= Q_{Pa(H_k^{})}(H_k^{})\\
   \implies P_{Pa(H_k^{})}(H_k^{})&=  Q_{Pa(H_k^{})}(H_k^{})
\end{split}
\end{equation}
