can you use inheritance (extension) in relax ng?

Hi,

I was wondering how something like this would be represented in RNG:

<xs:complexType name="SiteNode">
    <xs:sequence>
      <xs:group ref="lsb:core.elems"/>
    </xs:sequence>
    <xs:attributeGroup ref="lsb:navigable.attrs"/>
  </xs:complexType>

<xs:element name="folder">
    <xs:complexType>
      <xs:complexContent>
        <xs:extension base="lsb:SiteNode">
          <xs:sequence>
            <xs:group ref="lsb:folder.elems"/>
          </xs:sequence>
        </xs:extension>
      </xs:complexContent>
    </xs:complexType>
  </xs:element>

Does RNG support extending elements like above?

Thanks,
-Rob