[Bug 4551] K-NormalizeUnicodeFunc-13

http://www.w3.org/Bugs/Public/show_bug.cgi?id=4551





------- Comment #4 from mike@saxonica.com  2007-05-31 10:01 -------
>It almost seems as if a type which matches no values should have the unusual quantifier of zero.

I handled it that way at one time but it caused too many problems. I now type
error() as item(), which works for optimistic typing - it means that error()
will never cause a static type error, except in the pathological case where the
required type is empty-sequence(), because item() overlaps every other type.
(Perhaps I should have chosen item()? which would work for empty-sequence() as
well...)