Problems trying to run FXSLT-XSLT2

I guessed that running runningTotal.xsl against booklist.xml
might be a reasonable test, but it fails rather miserably:

At line 46 in file:///home/colin/fxslt/runningTotal.xsl:
Fatal error: XP0017: XPath syntax error in %Go??%@...e-set($vrtfSingleBookAmounts)/*%Go??%@:
    Unknown function: saxon:node-set
At line 46 in file:///home/colin/fxslt/runningTotal.xsl:
Fatal error: XP0017: XPath syntax error in %Go??%@...e-set($vrtfSingleBookAmounts)/*%Go??%@:
    Unknown function: saxon:node-set
At line 51 in file:///home/colin/fxslt/runningTotal.xsl:
Fatal error: XP0017: XPath syntax error in %Go??%@...n:node-set($vrtfRunningTotal)/*%Go??%@:
    Unknown function: saxon:node-set
At line 51 in file:///home/colin/fxslt/runningTotal.xsl:
Fatal error: XP0017: XPath syntax error in %Go??%@...n:node-set($vrtfRunningTotal)/*%Go??%@:
    Unknown function: saxon:node-set
Could not compile stylesheet: There were error compiling the stylesheet

What's an XSLT2 version doing trying to use saxon:node-set? 
XSLT2 doesn't need any node-set extension functions.
-- 
Colin Paul Adams
Preston Lancashire