\ontology#poem{
	\struct#poem[root=true]
		\field
			\childRef[ref=stanza]
	\struct#stanza[transparent=true]
		\syntax
			\close{\paragraph}
		\field
			\childRef[ref=line]
			\childRef[ref=indentation]
	\struct#line[transparent=true]
		\syntax
			\close{\newline}
		\primitive[type=string]
	\struct#indentation
		\syntax
			\open{\indent}
			\close{\dedent}
		\field
			\childRef[ref=line]
			\childRef[ref=indentation]
}