1<grammar xmlns="http://relaxng.org/ns/structure/1.0"> 2 3 <start> 4 <ref name="AddressBook"/> 5 </start> 6 7 <define name="AddressBook"> 8 <element name="addressBook"> 9 <zeroOrMore> 10 <ref name="Card"/> 11 </zeroOrMore> 12 </element> 13 </define> 14 15 <define name="Card"> 16 <element name="card"> 17 <ref name="Name"/> 18 <ref name="Email"/> 19 </element> 20 </define> 21 22 <define name="Name"> 23 <element name="name"> 24 <text/> 25 </element> 26 </define> 27 28 <define name="Email"> 29 <element name="email"> 30 <text/> 31 </element> 32 </define> 33 34</grammar> 35