Re: [Moderator Action] how to model "at least one element ..."

The traditional approach to this is ((a,b?)|b).  If you allow either
order then it's ((a,b?)|(b,a?)).  So in XML Schema syntax that's 

 <xs:choice>
  <xs:sequence>
   <xs:element ref="a"/>
   <xs:element ref="b" minOccurs="0"/>
  </xs:sequence>
  <xs:element ref="b"/>
 </xs:choice>

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2001, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@cogsci.ed.ac.uk
		     URL: http://www.ltg.ed.ac.uk/~ht/

Received on Friday, 9 March 2001 11:42:15 UTC