title: Nested sequence in XSD
body: <p>I would like to validate this XML:</p>
  
  <pre><code>&lt;meta&gt;
      &lt;house&gt;
          &lt;big ... /&gt;
          &lt;little ... /&gt;
          &lt;big ... /&gt;
      &lt;/house&gt;
  
      &lt;flat&gt;
          &lt;red ... /&gt;
          &lt;red ... /&gt;
          &lt;yellow ... /&gt;
      &lt;/flat&gt;
  &lt;/meta&gt;
  </code></pre>
  
  <p>I wrote that.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"&gt;
      &lt;xs:element name="meta"&gt;
          &lt;xs:complexType&gt;
              &lt;xs:sequence minOccurs="0" maxOccurs="unbounded"&gt;
                  &lt;xs:element name="house"&gt;
                      &lt;xs:complexType&gt;
                          &lt;xs:sequence minOccurs="0" maxOccurs="unbounded"&gt;
                              &lt;xs:element name='big' /&gt;
                              &lt;xs:element name='little' /&gt;
                          &lt;/xs:sequence&gt;
                      &lt;/xs:complexType&gt;
                  &lt;/xs:element&gt;
                  &lt;xs:element name="flat"&gt;
                      &lt;xs:complexType&gt;
                          &lt;xs:sequence minOccurs="0" maxOccurs="unbounded"&gt;
                              &lt;xs:element name='red'/&gt;
                              &lt;xs:element name='yellow'/&gt;
                          &lt;/xs:sequence&gt;
                       &lt;/xs:complexType&gt;
                   &lt;/xs:element&gt;
              &lt;/xs:sequence&gt;
          &lt;/xs:complexType&gt;
      &lt;/xs:element&gt;
  &lt;/xs:schema&gt;
  </code></pre>
  
  <p>But that does not validate my example.
  Without 'house' or 'flat', and only meta, that worked.</p>
  
  <p>Where could be my problem ?</p>