Re: Difference for attribute values

[Murata Makoto <mura034@attglobal.net>]

James Clark wrote:

> I am wondering whether we could allow <difference> in a very limited
> fashion that would be sufficient to support this use case.  For example,
> allowing <difference> where each operand matches exactly one string. 
> This would be easy to implement.  Wouldn't it also have the benefit of
> making the language as a whole closed under difference?

I like this idea.  

Is <not> for <text/> only, or is it for <data ..> as well?  If 
we allow <data> to have <not>, we have to use equality 
check.  But it's there already.

Cheers,

Makoto