1 <?xml version=
"1.0" encoding=
"utf-8"?>
2 <xs:schema xmlns:
xs=
"http://www.w3.org/2001/XMLSchema">
3 <xs:element name=
"odd-page" type=
"xs:string"/>
4 <xs:element name=
"even-page" type=
"xs:string"/>
5 <xs:element name=
"book">
8 <xs:sequence minOccurs=
"0" maxOccurs=
"unbounded">
9 <xs:element ref=
"odd-page"/>
10 <xs:element ref=
"even-page"/>
12 <xs:element ref=
"odd-page" minOccurs=
"0"/>