<schema xmlns=“www.w3.org/2001/XMLSchema

targetNamespace="http://FOO" xmlns:foo="http://FOO">

<element name="foo" type="foo:type.A"/>

<simpleType name="type.A">
        <restriction>
                <simpleType>
                        <list itemType="integer"/>                      
                </simpleType>
                <length value="3"/>
        </restriction>
</simpleType>

<!--restriction base="foo:type.base.A">

</restriction-->

<simpleType name="type.base.A">
        <restriction>
                <simpleType>
                        <list itemType="integer"/>                              
                </simpleType>
        </restriction>
</simpleType>

</schema>