<?xml version="1.0" encoding="UTF-8"?>
<element name="BookStore" xmlns="http://relaxng.org/ns/structure/1.0"
         datatypeLibrary="http://www.w3.org/2001/XMLSchema-datatypes">
    <oneOrMore>
        <element name="Book">
            <element name="Title">
                <text/>
            </element>
            <element name="Author">
                <text/>
            </element>
            <element name="Date">
                <text/>
            </element>
            <element name="ISBN">
                <text/>
            </element>
            <element name="Publisher">
                <text/>
            </element>
            <optional>
                <element name="NumPages"> 
                    <data type="nonNegativeInteger"/>
                </element>
                <optional>
                    <element name="Hardcover"> 
                        <data type="boolean"/>
                    </element>
                    <optional>
                        <element>     
                            <anyName/>
                            <text/>
                        </element>
                        <zeroOrMore>
                            <element>     
                                <anyName/>
                                <text/>
                            </element>
                        </zeroOrMore>
                    </optional>
                </optional>
            </optional>

        </element>
    </oneOrMore>
</element>