> > $seq[>>EXP]    everything in $seq after the first item that 
> satisfies EXP
> > $seq[>>=EXP]   everything in $seq after and including -"-
> > $seq[<<EXP]    everything in $seq before the first item 
> that satisfies EXP
> > $seq[<<=EXP]   everything in $seq before and including -"-
> 
> couldn't one get there with, say,
> sequence-before(sequence, item+)

Not really. How would you do "return the subsequence of $S before the first
element that has @page='2'"?

It has to be higher-order.

Any solution that involves first finding the index position of the first
element that has @page='2' and then selecting by position is a bit of a
hack, and a solution that involves recursion is beyond the abilities of 90%
of the user base.

Michael Kay
http://www.saxonica.com/