[xsl] Kleene Operators

[Terry Badger <terry_badger@xxxxxxxxx>]

I have been using Michael Kay's XSLT book and see that the regex, XSL and DTD
occurrence operators are defined in set theory. I wonder how important this is
when we use them. I guess my question is: does something very useful happen as
the result of using these operators in XML activities that would not have
happened had we used something else?
Terry