<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified">

	<xs:element name="base">
		<xs:complexType>
			<xs:sequence>
				<xs:element ref="i1" maxOccurs="unbounded"/>
			</xs:sequence>
		</xs:complexType>
	</xs:element>
	
	<xs:element name="i1">
		<xs:complexType mixed="true">
			<xs:choice minOccurs="0" maxOccurs="unbounded">
				<xs:element ref="i2"/>
			</xs:choice>
		</xs:complexType>
	</xs:element>
	
	<xs:element name="i2">
		<xs:complexType mixed="true">
			<xs:choice minOccurs="0" maxOccurs="unbounded">
				<xs:element ref="i"/>
			</xs:choice>
		</xs:complexType>
	</xs:element>
	
	<xs:element name="i" type="xs:string"/>
</xs:schema>