>     <xsl:for-each select="tokenize( 'a c', '[ ]')">
>       <xsl:apply-templates select="/doc/*[current() eq 
> string(@id)]" />
>     </xsl:for-each>

The select="..."
> expression does not depend on a context node, as it is an 
> absolute path from the document root. 

Ah, but which document? A path expression starting with "/" selects from the
root of the document that contains the context node - but there isn't a
context node. You need to set a variable outside the for-each (perhaps a
global variable) and select from that.

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