Derivation by restriction from <any>

Is it possible to derive by restriction starting with an <any>?

e.g.

<complexType name="basetype">
  <sequence>
    <any maxOccurs="unbounded"/>
  </sequence>
</complexType>

<complexType name="newtype">
  <complexContent>
    <restriction base="my:basetype">
      <sequence>
        <element name="e1" type="string"/>
        <element name="e2" type="integer" minOccurs="0"/>
        <element name="e3" type="date" minOccurs="0"/>
      </sequence>    
    </restriction>
  </complexContent>
</complexType>

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Simon.Cox@csiro.au  CSIRO Exploration & Mining
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