> Learner: the tests for preceding or following sibling 'author'
> elements will only work within the context of children of 'book'
> elements, such as the 'author' elements. Evaluated in the context of
> the 'book', you never have 'author' element siblings at all (by
> design), so these tests always return false.
>

The xml file is:

<?xml version="1.0" encoding="utf-8"?>
<!-- Edited by XMLSpyB., taken from http://www.w3schools.com-->
<?xml-stylesheet type='text/xsl" href="xstylesheetexample.xslt" ?>
<bookstore>
...
	<book category="WEB">
		<title lang="en">XQuery Kick Start</title>
		<author>James McGovern</author>
		<author>Per Bothner</author>
		<author>Kurt Cagle</author>
		<author>James Linn</author>
		<author>Vaidyanathan Nagarajan</author>
		<year>2003</year>
		<price>49.99</price>
	</book>
	<book category="WEB">
		<title lang="en">Learning XML</title>
		<author>Erik T. Ray</author>
		<year>2003</year>
		<price>39.95</price>
	</book>
</bookstore>

Perhaps my description was erroneous, but my understanding of the
structure of this xml file is that the element 'author' for "Per..."
is an expression "following-sibling" for the preceding element
'author' for "James...". Is it wrong to conclude that the elements
'author' are classified as sibling elements for the book title "xquery
kick start"?

>
> I hope that helps.
>

Thanks, application of the example produces:

...
				,
			James Linn
				 and
			Vaidyanathan Nagarajan</p>
...

The stage is see whether xslt offers css-type capability to apply
formatting based upon certain conditions, in this case changing the
block-level line breaks to in-line span-level formatting for >1
sibling elements. Excuse me for more reading!