Using @validation and @type?

Dear XSL-list,

I'm beginning to explore schema-aware processing, and for a real project I
need to create some temporary elements with attributes that I would like to
treat as integers. In the non-schema-aware version I explicitly pass the
attributes through the number() function when I need integer behavior, and
that does what I want, but I thought that if I typed the values as
xs:integer when creating them they would be recognized as instances of that
type when used, and would have integer behavior, so that I could
avoid using the number() function explicitly.

I created a small test sample below that replicates the problem I see in my
real code, and I would be grateful if someone could please advise about
what I've misunderstood. What I think I'm doing is creating a a variable
that contains <cell> elements with @row attributes that are typed as
xs:integer, and that therefore should behave as integers when I use them.
But when I test in the <xsl:for-each> at the end whether they are instances
of integers, the system reports that they are not. I'm running the tests at
the command line with Saxon EE and the -sa and -it switches. Thank you for
any guidance you might be able to provide.

Best,

David
__

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="xs" version="3.0">
    <xsl:output method="xml" indent="yes"/>
    <xsl:template name="xsl:initial-template">
        <xsl:variable name="test" as="element(test)">
            <test xsl:validation="preserve">
                <xsl:for-each select="1 to 5">
                    <cell>
                        <xsl:attribute name="row" type="xs:integer"
select="."/>
                        <xsl:text>Hi!</xsl:text>
                    </cell>
                </xsl:for-each>
            </test>
        </xsl:variable>
        <xsl:for-each select="$test//cell">
            <xsl:message select="@row, @row instance of xs:integer"/>
        </xsl:for-each>
        <root>
            <xsl:sequence select="$test"/>
        </root>
    </xsl:template>
</xsl:stylesheet>