1<grammar xmlns="http://relaxng.org/ns/structure/1.0"> 2 3 <define name="inline"> 4 <zeroOrMore> 5 <ref name="inline.class"/> 6 </zeroOrMore> 7 </define> 8 9 <define name="inline.class"> 10 <choice> 11 <text/> 12 <element name="bold"> 13 <ref name="inline"/> 14 </element> 15 <element name="italic"> 16 <ref name="inline"/> 17 </element> 18 </choice> 19 </define> 20 21</grammar> 22