[xsl] problem with boolean AND expression [false AND false ->true] in xslt2.0

["Robby Pelssers" <robby.pelssers@xxxxxxxxx>]

Hi all,

I have the weirdest problem with the result of a AND expression of 2
booleans.  I'm using Saxon8.7 FYI.
    <xsl:variable name="symbolAndParameterAreEqual"
select="deep-equal($previousRow/Entry[1], $currentRow/Entry[1]) and
deep-equal($previousRow/Entry[2], $currentRow/Entry[2])"
as="xs:boolean"/>

    <xsl:comment>
    symbol matches precedingrow = <xsl:value-of
select="deep-equal($previousRow/entry[1], $currentRow/entry[1])"/>
    parameter matches precedingrow = <xsl:value-of
select="deep-equal($previousRow/entry[2], $currentRow/entry[2])"/>
    both are equal = <xsl:value-of
select="$symbolAndParameterAreEqual"/>
    </xsl:comment>

Results in
<!--
    symbol matches precedingrow = false
    parameter matches precedingrow = false
    both are equal = true
-->

The deep-equal function always returns the good result but when
combining the two Boolean results in an AND expression they always
return True.

Anyone who can shed any light onto this problem?

Kind regards,
Robby Pelssers
http://robbypelssers.blogspot.com/