Re: optional, but at least one required

Hi Brian,

Then a model like (a|b|c)+ looks like exactly what want.

Best Regards,
George
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George Cristian Bina
<oXygen/> XML Editor, Schema Editor and XSLT Editor/Debugger
http://www.oxygenxml.com


Brian Bonner wrote:
> George, Michael,  thanks.
> 
> I'm sorry I wasn't complete.  Yes, multiple occurrences of a, b and c
> are allowed.  That's a critical piece I left out.
> 
> 
> So, someone could create:
> 
> <options>
>      <a/>
> </options>
> 
> <options>
>      <a/>
>      <b/>
> </options>
> 
> <options>
>       <b/>
> </options>
> 
> <options>
>       <a/>
>       <b/>
>       <c/>
> </options>
> 
> and several others,
> 
> but not:
> 
> <options/>
> 
> So each of them are optional, but *at least* one of them must be
> specified and multiple can be specified at once.
> 
> I think George's model which imposes ordering on the elements might do
> the trick.  I'll give that a shot.
> 
> Thank you.
> 
> Brian