Hi Guys

Thanks for all the input. Dimitre, your suggestion is something I had
tried as well. Unfortunately I don't think it quite works... Well,
more specially it *does* work for the one example I posted, but
imagine if I added another book below the last one with the author
Mary. (I put an updated XML snippet below) The the output for John is:
1, 3, 5,
(Since the 5th book is no longer the last book overall, a comma is
added after the 5.)

The reason I am trying to use XPath is I am being forced to use Altova
StyleVision for this project, and as far as I am aware,  StyleVision
won't let me do this any other way (i.e. using the XLST or XQuery).

After I posted this, I realized the problem is actually more
complicated than I had previously thought. The point is actually to
create a detailed list of books, sorted by title (title is just
another element inside book) with a summary on top telling which books
below correspond to the given authors by the position the book appears
in the report. I put an example below. So I don't know if this is
going to be possible.  If anyone has any other thoughts, either for
the first problem as an intellectual exercise, or to the 'revised'
situation--including using XSLT or XQuery--that'd be great. Otherwise
thanks for all the input!

Output example
Books by John: 1, 2, 5
Books by Mary: 3, 6
Books by Mark: 4

Book 1:
Title: A Book Title Starting With 'A'
Author: John

Book 2:
Title: Books Are Fun!
Author: John

Book 3:
Title: Can You Tell Me How To Get To Sesame Street?
Author Mary
...



XML Example
<?xml version="1.0" encoding="UTF-8"?>
<Library>
<Branch>
<book>
<author>John</author>
</book>
<book>
<author>Mary</author>
</book>
</Branch>
<Branch>
<book>
<author>John</author>
</book>
<book>
<author>Mark</author>
</book>
<book>
<author>John</author>
</book>
<book>
<author>Mary</author>
</book>
</Branch>
</Library>


On Dec 2, 10:26 pm, "Dimitre Novatchev" <dimit...@tpg.com.au> wrote:
> "Joe Kesselman" <keshlam-nos...@comcast.net> wrote in message
>
> news:gqmdnXmD4cUuFszanZ2dnUVZ_tLinZ2d@c......
>
> >>           /(if(author='John')
>
> > I believe if/then/else expressions require XPath 2.0 or XQuery. If that's
> > what you have available, go for it;
>
> Yes, this was the code in the OP first post.
>
> Cheers,
> Dimitre Novatchev