Re: Extending a choice model group in the derived type

If the minOccurs of the choice group is 0 then the derivation can be done by
first extending the content model and then restricting it:

(x|y)? extended into (x|y)? (x|y|z)? restricted into (x|y|z)? (by dropping
an emtiable particle).

--Stefan

> 
> If I have a base type B with the following content mode
>  
> B = (x | y) 
>  
> is there a way to create a derived type D with content model
>  
> D = (x |y |z) 
>  
>  
>  
> I thought of extension but at best I can create 
>  
> D = (x|y) z 
>  
> Restriction similarly doesn't work. Perhaps there is some clever way to do
> this with substitution groups I haven't thought of. 
> 

Received on Thursday, 22 August 2002 15:11:13 UTC