\begin{document} \ontology#testOntology \struct#test[root=true] \field \childRef[ref=a] \childRef[ref=b] \struct#a \field \childRef[ref=b] \struct#b[transparent=true] \primitive[type=string,optional=true] \begin{test} \a \include{./include_child.osml} \b Test \end{test} \end{document}