<grammar xmlns=“relaxng.org/ns/structure/1.0”>
<define name="inline"> <zeroOrMore> <choice> <text/> <element name="bold"> <ref name="inline"/> </element> <element name="italic"> <ref name="inline"/> </element> <ref name="inline.extra"/> </choice> </zeroOrMore> </define> <define name="inline.extra"> <notAllowed/> </define>
</grammar>