Confused with Xpath expression! Need Help.

[Vivek Saxena]

Hi,
Following question is from "Test 3 " of XMLWhiz. I am having problem to
under stand the Xpath expression.

How many elements will be output when the following XSL sheet is applied to the following 
XML document?
--------------------XSL Document-------------------------
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> 
<xsl:template match="/">
<xsl:element name='Root'>
<xsl:call-template name="v3"/>
</xsl:element>
</xsl:template>
<xsl:template name="v3">
<xsl:variable name="v3List" select="//a[not(following::x=.)] | //x[not(preceding::a=.)] "/>
<xsl:for-each select="$v3List">
<a><xsl:value-of select="."/></a>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
--------------------XML Document-------------------------
<Root>
<B>
<a>1</a>
<a>2</a>
<a>1</a>
<x>3</x>
<x>4</x>
<x>2</x>

</B>
<B>
<a>3</a>
<a>1</a>
<a>2</a>
<a>3</a>
<x>5</x>
<x>4</x>
<x>1</x>
</B>
</Root>

What is the difference between
"//a[(following::x)]"
&
"//a[(following::x=.)]"

I know with "//a[(following::x)]" we will get all "a" elements which has "x" as following element.
I have no idea about the expression
"//a[(following::x=.)]".
Please help me !

Thanks
[ March 10, 2003: Message edited by: Vivek Saxena ]

[Vivek Saxena]

Any help would great!
Waiting.
Thanks

[Raj Yelnare]

When I did use the stylesheet as
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<xsl:element name='Root'>
<xsl:call-template name="v3"/>
</xsl:element></xsl:template>
<xsl:template name="v3">
<xsl:variable name="v3List" select="//a[not(following::x=.)] | //x[not(preceding::a=.)] "/>
<xsl:for-each select="$v3List"><a><xsl:value-of select="."/>
</a></xsl:for-each>
</xsl:template>
</xsl:stylesheet>
The browser gave me
3432354
When I included the stylesheet as
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:template match="/">
<xsl:element name='Root'>
<xsl:call-template name="v3"/>
</xsl:element></xsl:template>
<xsl:template name="v3">
<xsl:variable name="v3List" select="//a[not(following::x)] | //x[not(preceding::a=.)] "/>
<xsl:for-each select="$v3List"><a><xsl:value-of select="."/>
</a></xsl:for-each>
</xsl:template>
</xsl:stylesheet>
The browser gave me
3454

[Vivek Saxena]

This is what i don't understand. There is a difference between "//a[(following::x)]" &
"//a[(following::x=.)]" but i am not able to find/define the difference in words.
Any help would be appreciated.
Thanks

[Roseanne Zhang]

//a[following::x]
Select all a elements which has x in its following axis.
//a[following::x = .]
Select all a elements which has x in its following axis and the x node value equals the node a's value.

[Vivek Saxena]

Oh , Now i get it.
Thanks you Roseanne.
Thanks