[relax-ng] Why is the start element always mandatory when a grammar isused

Hi,

Just out of curiousity, is there a reason why as soon as a grammar
element is used a start element is mandatory even when there is no
ambiguity about the root element such as in:

<grammar>
 <define name="bar">
  <element name="bar">
   <empty/>
  </element>
 </define>
 <element name="foo">
  <ref name="bar"/>
 </element>
</grammar>

Is there any reason other than making the simplification of the schema
easier to describe and implement?

Thanks

Eric

-- 
See you in San Diego.
                               http://conferences.oreillynet.com/os2002/
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Eric van der Vlist       http://xmlfr.org            http://dyomedea.com
(W3C) XML Schema ISBN:0-596-00252-1 http://oreilly.com/catalog/xmlschema
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